pvlib

Deprecations

Deprecate pvlib.location.Location.pytz . Use tz instead. ( GH2343 , GH2757 )

Rename pvlib.irradiance.ghi_from_poa_driesse_2023() to ghi_from_poa_driesse_2024() . The year now reflects the publication date. The old name will be removed in v0.17.0. ( GH2774 , GH2777 )

Bug fixes

Fix pvlib.temperature.fuentes() truncating the output if poa_global input was data type integer. Users can expect modeled cell temperature values to increase slightly. ( GH2608 , GH2745 )

Fix a regression in pvlib.tracking.calc_surface_orientation() introduced in v0.15.1 ( GH2702 ) that caused a broadcasting ValueError when tracker_theta was a 2-D (or higher rank) array. ( GH2747 , GH2749 )

Document that timestamps returned by get_era5() represent the end of the averaging interval, consistent with ERA5 conventions. ( GH2772 , GH2773 )

Fix header parsing in pvlib.iotools.read_nsrdb_psm4() with quoted commas in column names. This allows spectral-on-demand files to be read. ( GH2736 , GH2771 )

Update get_meteonorm_tmy() to comply with the updated Meteonorm API. As part of this, the data_version parameter now has no effect and will be removed in the future. ( GH2781 )

Enhancements

Add the front_side_fraction parameter to pvlib.snow.loss_townsend() to support Townsend snow-loss workflows for bifacial systems. ( GH2755 , GH2756 )

Add the following parameters to get_nasa_power() when map_variables=True : temp_dew , precipitable_water , relative_humidity , ghi_extra , dhi_clear , longwave_down , and albedo . ( GH2731 , GH2753 , GH2762 )

Documentation

Clarify that pvlib.soiling.hsu() has an implicit minimum soiling ratio of approximately 0.6563 due to the mathematical form of the model. ( GH2534 , GH2743 )

Clarify how Linke turbidity values can be provided to pvlib.clearsky.ineichen() via pvlib.clearsky.lookup_linke_turbidity() . ( GH2598 , GH2746 )

Testing

Add test coverage for pvlib.irradiance.dirint() with np.array and pd.Series inputs. ( GH2751 , GH2752 )

Contributors

@Omesh37

@gaoflow

Cliff Hansen ( @cwhanse )

@shethkajal7

Arthur Onno ( @ArthurOnnoTerabase )

Adam R. Jensen ( @AdamRJensen )

@JoLo90

Karl Hill ( @karlhillx )

Rajiv Daxini ( @RDaxini )

Vincent Filter ( @vfilter )

Klaus Jäger ( @solartube )

Carolina Crespo ( @cbcrespo )

Ioannis Sifnaios ( @IoannisSifnaios )

Anton Driesse ( @adriesse )

Mark Mikofski ( @mikofski )

Rodrigo Amaro e Silva ( @ramaroesilva )

Will Hobbs ( @williamhobbs )

Echedey Luis ( @echedey-ls )

Cliff Hansen ( @cwhanse )

Will Holmgren ( @wholmgren )

Kevin Anderson ( @kandersolar )

Bug fixes

Fix a bug in pvlib.scaling.latlon_to_xy() where latitude scaling was incorrectly applied to both latitude and longitude components. ( GH2614 , GH2712 )

Fix a division-by-zero condition in pvlib.transformer.simple_efficiency() when load_loss = 0 . ( GH2645 , GH2646 )

Update URLs in pvlib.iotools.psm4 to use nlr.gov instead of nrel.gov. ( GH2701 , GH2705 )

Fix a bug in pvlib.iotools.get_era5() where conversion of precipitation in meters to cm was underestimated by a factor of 10,000 when map_variables=True . ( GH2724 , GH2725 )

Enhancements

Use k and cap_adjustment from pvlib.pvsystem.Array.module_parameters in pvlib.pvsystem.PVSystem.pvwatts_dc() ( GH2714 , GH2715 )

Include ross and faiman_rad in the allowed models within pvlib.pvsystem.PVSystem.get_cell_temperature() ( GH2625 , GH2631 )

Accelerate the internals of ephemeris() . ( GH2626 )

Accelerate the internals of singlediode() when method='lambertw' . ( GH2732 , GH2723 )

Accept negative axis_tilt values in singleaxis() . ( GH2702 , GH1976 )

Documentation

Add examples for pvlib.modelchain.ModelChain.run_model_from_poa() and run_model_from_effective_irradiance() ( GH1043 , GH2621 )

Add the following terms to the Nomenclature page ( GH2564 , GH2663 ):

clearness_index

clearsky_index

aod

iam

aod500

Add an overview of IAM modeling functionality in new documentation page Incidence angle modifier . ( GH2683 )

Add AI checkbox to PR template, and auto-generate a comment on PRs from first-time contributors regarding AI and contributing guidelines. ( GH2617 , GH2624 )

Clarify pvlib.pvsystem.PVSystem parameter module_type is optional. ( GH2634 , GH2713 )

Fix a broken docstring reference to grounddiffuse in pvlib.irradiance.poa_components() ( GH2089 , GH2708 )

Add Core guidelines to the Introduction to contributing page. ( GH2716 , GH2726 )

Testing

Add test to verify that simple_efficiency() produces consistent results for vectorized and scalar inputs. ( GH2649 , GH2661 )

Maintenance

Update all NREL references to NLR (National Laboratory of the Rockies) following the laboratory rename and domain migration from nrel.gov to nlr.gov . Rename NREL_API_KEY environment variable to NLR_API_KEY . ( GH2701 , GH2705 )

Contributors

Aman Srivastava ( @aman-coder03 )

Rajiv Daxini ( @RDaxini )

Echedey Luis ( @echedey-ls )

Cliff Hansen ( @cwhanse )

Anton Driesse ( @adriesse )

Kevin Anderson ( @kandersolar )

Jason Curtis ( @jason-curtis )

Rohan Saxena ( @r0hansaxena )

Marco Fumagalli ( @fuma900 )

Jean-Baptiste Pasquier ( @pasquierjb )

Rodrigo Amaro e Silva ( @ramaroesilva )

James Fulton ( @dfulu )

Will Holmgren ( @wholmgren )

Mark Campanelli ( @markcampanelli )

Chirag Sharma ( @Chirag3841 )

Will Hobbs ( @williamhobbs )

Adam R. Jensen ( @adamrjensen )

Breaking Changes

Removed expired parameter name deprecations ( GH2662 , GH2666 ):

Parameter clearsky_ghi in pvlib.irradiance.clearsky_index()

Parameters ghi_clearsky and dni_clearsky in pvlib.irradiance.dirindex()

Parameter clearsky_dni in pvlib.irradiance.dni()

Documentation

Update gallery examples to work with pandas==3 ( GH2664 ).

Contributors

Echedey Luis ( @echedey-ls )

Aman Srivastava ( @aman-coder03 )

Cliff Hansen ( @cwhanse )

Adam R. Jensen ( @adamrjensen )

Will Holmgren ( @wholmgren )

Rajiv Daxini ( @RDaxini )

Anton Driesse ( @adriesse )

Kevin Anderson ( @kandersolar )

Breaking Changes

Following the removal of the NSRDB PSM3 API, the pvlib.iotools.get_psm3() , pvlib.iotools.read_psm3() , and pvlib.iotools.parse_psm3() functions are removed. ( GH2581 , GH2582 )

Rename output column names to be prefixed with "poa_" when return_components=True in haydavies() , perez() , and perez_driesse() . ( GH2529 , GH2627 )

Enhancements

Add fit_desoto_batzelis() , a function to estimate parameters for the De Soto single-diode model from datasheet values. ( GH2563 )

Add batzelis() , a function to estimate maximum power, open circuit, and short circuit points using parameters for the single-diode equation. ( GH2563 )

Add batzelis() , a function to estimate maximum power open circuit, and short circuit points from datasheet values. ( GH2563 )

Add method='chandrupatla' (faster than brentq and slower than newton , but convergence is guaranteed) as an option for pvlib.pvsystem.singlediode() , i_from_v() , v_from_i() , max_power_point() , bishop88_mpp() , bishop88_v_from_i() , and bishop88_i_from_v() . ( GH2497 , GH2498 )

Add Marion 2008 non-linear irradiance adjustment factor to pvlib.pvsystem.pvwatts_dc() . ( GH2566 , GH2569 )

Accelerate singlediode() when scipy>=1.15 is installed. ( GH2497 , GH2571 )

Add get_era5() , a function for accessing ERA5 reanalysis data. ( GH2573 )

Add get_merra2() , a function for accessing MERRA-2 reanalysis data. ( GH2572 )

Add spectral_factor_polo() , a function for estimating spectral mismatch factors for vertical PV façades. ( GH2406 , GH2491 )

Documentation

Provide an overview of single-diode modeling functionality in Single diode models . ( GH2565 )

Provide an overview of temperature modeling functionality in Temperature models . ( GH2591 )

Fix typo in parameter name atmos_refract in pvlib.solarposition.spa_python() and pvlib.spa.solar_position() . ( GH2532 , GH2592 )

Testing

Add Python 3.14 to test suite. ( GH2590 )

Update pytest configuration in pyproject.toml to work with pytest 9.0. ( GH2596 )

Correct argument and value order in test_sde() , in tests of _fit_sandia_cocontent() . ( GH2613 , GH2615 )

Requirements

Advance minimum solarfactors to v1.6.1. ( GH2656 )

Contributors

Will Hobbs ( @williamhobbs )

Cliff Hansen ( @cwhanse )

Joseph Radford ( @josephradford )

Jesús Polo ( @jesuspolo )

Adam R. Jensen ( @adamrjensen )

Echedey Luis ( @echedey-ls )

Anton Driesse ( @adriesse )

Rajiv Daxini ( @RDaxini )

Kevin Anderson ( @kandersolar )

Mark Mikofski ( @mikofski )

Will Holmgren ( @wholmgren )

Ioannis Sifnaios ( @IoannisSifnaios )

Mark Campanelli ( @markcampanelli )

Aman Srivastava ( @aman-coder03 )

Vincent Filter ( @vfilter )

Deprecations

Deprecate pvlib.modelchain.get_orientation() . ( GH2495 )

Rename parameter name apparent_azimuth to solar_azimuth in singleaxis() . ( GH2479 , GH2480 )

Bug fixes

Fix detect_clearsky() to use inferred window length when infer_limits=True . ( GH2542 , GH2550 )

Enhancements

Add option to use the latest parameters for the Huld PV array model huld() . ( GH2461 , GH2486 )

Add option to specify k coefficient in ross() . ( GH2506 , GH2521 )

Add iotools functions to retrieve irradiance and weather data from Meteonorm: get_meteonorm_forecast_basic() , get_meteonorm_forecast_precision() , get_meteonorm_observation_realtime() , get_meteonorm_observation_training() , and get_meteonorm_tmy() . ( GH2499 )

Add pvlib.iotools.get_nasa_power() to retrieve data from NASA POWER free API. ( GH2500 )

pvlib.spectrum.spectral_factor_firstsolar() no longer emits warnings when airmass and precipitable water values fall out of range. ( GH2512 )

Allow reading TMY data from a Path or file-like object in read_tmy3() . ( GH2544 )

Documentation

Update pvlib.irradiance module documentation to include links to parameter definitions from the nomenclature page, ensure consistent parameter description structure, add units to all parameters where required, and other miscellaneous edits. ( GH2205 , GH2248 , GH2311 )

Substantiate definitions of solar/surface azimuth/zenith and aoi on the Nomenclature page. ( GH2448 , GH2503 )

Add a new reference page for the spectrum ( Spectrum ) to the Modeling Topics section of the user guide, documenting pvlib-python’s spectrum functionality, which includes a comparison table of spectral mismatch estimation models. ( GH2329 , GH2353 )

Fix FAQ URL in README.md . ( GH2488 )

Requirements

Drop support for Python 3.9 (reaches End of Life in Oct 2025). ( GH2547 )

Advance minimum numpy to 1.21.2. ( GH2547 )

Advance minimum scipy to 1.7.2. ( GH2547 )

Advance minimum pandas to 1.3.3. ( GH2547 )

Maintenance

Switch to using Trusted Publishing for deploying releases to PyPI. ( GH2511 , GH2549 )

Contributors

Elijah Passmore ( @eljpsm )

Omar Bahamida ( @OmarBahamida )

Cliff Hansen ( @cwhanse )

Ioannis Sifnaios ( @IoannisSifnaios )

Rajiv Daxini ( @RDaxini )

Rodrigo Amaro e Silva ( @ramaroesilva )

Kevin Anderson ( @kandersolar )

Mikaella Brewer ( @brwerx )

Will Holmgren ( @wholmgren )

Jeremy Lucas ( @jerluc )

Adam R. Jensen ( @AdamRJensen )

Will Hobbs ( @williamhobbs )

Echedey Luis ( @echedey-ls )

Anton Driesse ( @adriesse )

Mark Mikofski ( @mikofski )

Mathias Aschwanden ( @maschwanden )

@leopardracer

Breaking Changes

The functions read_pvgis_hourly() and get_pvgis_hourly() now return (data,meta) following the iotools convention instead of (data,inputs,meta) . The inputs dictionary is now included in meta , which has changed structure to accommodate it. ( GH2462 )

The functions read_pvgis_tmy() and get_pvgis_tmy() now return (data,meta) following the iotools convention instead of (data,months_selected,inputs,meta) . ( GH2470 )

get_pvgis_tmy() now defaults to coerce_year=1990 , whereas the default behavior previously was to use the years of the selected months for the TMY index. ( GH2474 )

Remove outputformat='basic' option in get_pvgis_tmy() . ( GH2416 )

Deprecations

The following parse_ functions in pvlib.iotools are deprecated, with the corresponding read_ functions taking their place: ( GH2444 , GH2458 , GH2467 , GH2466 )

parse_epw()

pvlib.iotools.parse_psm3()

parse_cams()

parse_bsrn()

The server parameter in get_cams() has been renamed to url to be consistent with the other iotools. GH2463

Rename parameter name g_poa_effective to effective_irradiance in pvwatts_dc() and pvwatts_dc() . ( GH1253 , GH2235 )

Bug fixes

pvlib.iotools.get_pvgis_tmy() now returns the correct dtypes when when outputformat='epw' . ( GH2399 , GH2417 )

Enhancements

pvlib.ivtools.sdm is now a subpackage. ( GH2252 , GH2256 )

Add a function for estimating PVsyst SDM parameters from IEC 61853-1 matrix data ( fit_pvsyst_iec61853_sandia_2025() ). ( GH2185 , GH2429 )

The parameters for the Ix and Ixx points are now optional when using pvlib.pvsystem.sapm() directly and through PVSystem and ModelChain . ( GH2402 , GH2433 )

Add optional arguments temperature_ref and irradiance_ref to sapm() ( GH2432 , GH2434 )

Add NREL NSRDB PSM v4 API client to pvlib.iotools . See get_nsrdb_psm4_aggregated() , get_nsrdb_psm4_tmy() , get_nsrdb_psm4_conus() , get_nsrdb_psm4_full_disc() , and read_nsrdb_psm4() . ( GH2326 , GH2378 , GH2445 )

pvlib.bifacial.infinite_sheds no longer emits “invalid value” warnings when supplying irradiance arrays with nighttime zero values. ( GH2450 , GH2451 )

Add 'semi_integrated' parameters for the PVsyst temperature model. ( GH2330 , GH2415 )

Documentation

Add a supporting reference to pvlib.atmosphere.get_relative_airmass() ( GH2390 , GH2424 )

Document how np.nan values are handled by average_photon_energy() ( GH2423 , GH2426 )

Clarify which SAPM coefficients are required by the module parameter in sapm() ( GH2392 , GH2435 )

Add gallery example on calculating irradiance at crop level for agriPV systems. ( GH2459 )

Update references in get_extra_radiation() ( GH2333 , GH2347 )

Update references in get_cams() and read_cams() ( GH2427 , GH2457 )

Fix Edit on GitHub links in stable documentation so they point to the tagged repository version matching the build environment (e.g., v0.12.0). ( GH2456 , GH2460 )

Fix a minor issue with calculation of solar position in the OEDI 9068 gallery page. ( GH2468 )

Requirements

wheel is no longer a build dependency. ( GH2439 )

Maintenance

Update pyproject.toml to replace deprecated license table and classifiers. ( GH2440 , GH2441 )

Contributors

Cliff Hansen ( @cwhanse )

Rajiv Daxini ( @RDaxini )

Will Hobbs ( @williamhobbs )

Kevin Anderson ( @kandersolar )

Will Holmgren ( @wholmgren )

Muhammad Rebaal ( @Muhammad-Rebaal )

Echedey Luis ( @echedey-ls )

omahs ( @omahs )

Adam R. Jensen ( @AdamRJensen )

Marion Schroedter-Homscheidt ( @mschroedter )

Anton Driesse ( @adriesse )

Mark Mikofski ( @mikofski )

Ioannis Sifnaios ( @IoannisSifnaios )

Mark Campanelli ( @markcampanelli )

Paul Gilman ( @cpaulgilman )

Yu Xie ( @xieyupku )

Grant Buster ( @grantbuster )

Breaking Changes

The pvlib.location.Location.pytz attribute is now read only. The pytz attribute is now set internally to be consistent with the pvlib.location.Location.tz attribute. ( GH2340 , GH2341 )

Users must now provide ModelChain.spectral_model , or the 'no_loss' spectral model is assumed. ModelChain no longer attempts to infer the spectral model from PVSystem attributes. ( GH2017 , GH2253 )

Remove deprecated pvlib.pvsystem.sapm_spectral_loss() ; use spectral_factor_sapm() instead. ( GH2243 , GH2244 )

read_tmy3() now defaults to map_variables=True . Additionally, the deprecated recolumn parameter is now removed. ( GH2324 , GH2408 )

Remove pvlib.atmosphere.first_solar_spectral_correction() , deprecated in v0.10.0. Use spectral_factor_firstsolar() instead. ( GH2130 , GH2131 )

Remove deprecated pvlib.spectrum.get_am15g() function; use get_reference_spectra() instead. ( GH2409 )

Change default method of get_sun_rise_set_transit() to 'spa' instead of 'pyephem' . ( GH2410 )

Bug fixes

Add a check to fully_covered_nrel() and coverage_nrel() . The check uses snow depth on the ground to improve modeling for systems with shallow tilt angles. The check adds a new, optional parameter snow_depth . ( GH1171 , GH2292 )

Fix a bug in pvlib.bifacial.infinite_sheds.get_irradiance_poa() which may have yielded non-zero ground irradiance when the sun was below the horizon. ( GH2245 , GH2359 )

Fix a bug where pvlib.transformer.simple_efficiency() could only be imported using the from pvlib.transformer syntax. ( GH2388 )

ModelChain now requires only a minimal set of parameters to run the SAPM electrical model. ( GH2369 , GH2393 )

Correct keys for First Solar modules in spectral_factor_pvspec() . ( GH2398 , GH2400 )

Ensure proper tz and pytz types in Location . To ensure that the time zone in Location remains internally consistent if/when the time zone is updated, the tz attribute is now the single source of time-zone truth, is the single time-zone setter interface, and its getter returns an IANA string. ( GH2340 , GH2341 )

get_pvgis_tmy() with outputformat='csv' now works with the updated data format returned by PVGIS. ( GH2344 , GH2395 )

Enhancements

gti_dirint() now raises an informative message when input data don’t include values with AOI<90. ( GH1342 , GH2347 )

Reduce space requirements by excluding tests and test files from wheel. Zipped wheel is now 66% of the previous size, and installed size is 50% of the previous size. ( GH2271 , GH2277 )

Documentation

Fix Procedural and Object Oriented simulation examples having slightly different results in Intro Tutorial . ( GH2366 , GH2367 )

Restructure the user guide with subsections. ( GH2302 , GH2310 )

Add references for pvlib.snow.loss_townsend() . ( GH2383 , GH2384 )

Add ghi_clear to the Nomenclature page. ( GH2272 , GH2397 )

Add output variable naming clarifaction to pvlib.pvsystem.calcparams_desoto() and pvlib.pvsystem.calcparams_pvsyst() . ( GH716 , GH2405 )

Testing

Move tests folder to /tests and data exclusively used for testing to /tests/data . ( GH2271 , GH2277 )

Add Python 3.13 to test suite. ( GH2201 , GH2258 )

Add tests for all input types for the pvlib.location.Location.tz attribute. ( GH2340 , GH2341 )

Add tests for time-conversion functions in pvlib.tools . ( GH2340 , GH2341 )

Maintenance

Fix ReadTheDocs builds by upgrading readthedocs.yml configuration ( GH2357 , GH2358 )

asv 0.4.2 upgraded to asv 0.6.4 to fix CI failure due to pinned older conda. ( GH2352 )

Contributors

Rajiv Daxini ( @RDaxini )

Cliff Hansen ( @cwhanse )

Jason Lun Leung ( @jason-rpkt )

Manoj K S ( @manojks1999 )

Kurt Rhee ( @kurt-rhee )

Ayush jariyal ( @ayushjariyal )

Kevin Anderson ( @kandersolar )

Echedey Luis ( @echedey-ls )

Mark Campanelli ( @markcampanelli )

Max Jackson ( @MaxJackson )

Anton Driesse ( @adriesse )

Adam R. Jensen ( @AdamRJensen )

Ioannis Sifnaios ( @IoannisSifnaios )

Will Holmgren ( @wholmgren )

Sophie Pelland ( @sophie-pelland )

Will Hobbs ( @williamhobbs )

Karel De Brabandere ( @kdebrab )

Kenneth J. Sauer ( @kjsauer )

Deprecations

Deprecate terms dni_clearsky and clearsky_dni , replace with dni_clear and ghi_clear . Affected functions are dirindex() , dni() and clearsky_index() .

Enhancements

Add rh_from_tdew() and tdew_from_rh() . ( GH1744 , GH2286 )

fit_desoto() now allows input of initial parameter guesses. ( GH1014 , GH2291 )

Bug Fixes

get_irradiance() accepts float inputs. ( GH1338 , GH2227 )

Handle DST transitions that happen at midnight in pvlib.solarposition.hour_angle() ( GH2132 GH2133 )

Change dni_extra to a required parameter in pvlib.irradiance.ghi_from_poa_driesse_2023() ( GH2279 GH2331 )

julian_day_dt() now accounts for the 10 day difference between Julian and Gregorian calendars prior to the year 1582. ( GH2077 , GH2249 )

Correct sign of temperature coefficient dEgdT in fit_desoto_sandia() . Results may differ slightly from previous versions. ( GH2311 , GH2322 )

Documentation

Edit docstrings for dc_ohms_from_percent() and dc_ohmic_losses() for clarity. ( GH1601 , GH2229 )

Add ‘freestanding’ and ‘insulated’ racking_model options for cell temperature calculation in PVSystem , SingleAxisTrackerMount , and FixedMount docstrings. Various formatting edits for clarity. ( GH1942 , GH2232 )

Update reindl() to include definitions of terms and a new “notes” section ( GH2183 , GH2193 )

Clarify the error message in detect_clearsky() when windows contain fewer than three data points ( GH2005 , GH2281 )

Clarify mounting cases for parameters for sapm_module() , sapm_cell() and pvsyst_cell() . ( GH1323 , GH2293 )

Add an example to retrieve_sam() docstring to demonstrate how to retrieve a database from the SAM repo. ( GH2313 )

Add a new citation style guide ( References ) to the contributing page. ( GH2202 , GH2226 )

Explain how to write docstrings for new functions in Example Docstring ( GH2081 , GH2254 )

Add a section in the style guide for parameter naming and units best practices. See Parameter names and units . ( GH2205 , GH2248 )

Add a new Nomenclature page, in place of the Variables and Symbols page, using the sphinx glossary directive. ( GH1421 , GH2234 )

Add the following variables to the Nomenclature page:

spectra and spectra_components ( GH2150 , GH2264 )

Testing

Update test files to track new PVGIS 5.3 data. ( GH2305 )

Maintenance

Add a decorator to deprecate renamed keyword arguments in functions, pvlib._deprecation.renamed_kwarg_warning() . ( GH2237 )

Contributors

Cliff Hansen ( @cwhanse )

Rajiv Daxini ( @RDaxini )

Dave Pitts ( @dgapitts )

Kurt Rhee ( @kurt-rhee )

Mark Mikofski ( @mikofski )

Roma Koulikov ( @matsuobasho )

Echedey Luis ( @echedey-ls )

Kevin Anderson ( @kandersolar )

Scott Nelson ( @scttnlsn )

Ioannis Sifnaios ( @IoannisSifnaios )

Adam R. Jensen ( @AdamRJensen )

Anton Driesse ( @adriesse )

Will Holmgren ( @wholmgren )

Umay Akkoseoglu ( @uakkoseo )

Mark Campanelli ( @markcampanelli )

@iblasi

Hiromasa Ihara ( @miettal )

Yunho Kee ( @yhkee0404 )

Hamilton Kibbe ( @hamiltonkibbe )

Felix Korbelius ( @FelixKoTU )

Michael Deceglie ( @mdeceglie )

Will Hobbs ( @williamhobbs )

Todd Karin ( @toddkarin )

Lucas Schneeberger ( @lucasschn )

Enhancements

Add new function to calculate the average photon energy, average_photon_energy() . ( GH2135 , GH2140 )

Add new losses function that accounts for non-uniform irradiance on bifacial modules, power_mismatch_deline() . ( GH2045 , GH2046 )

Add new parameters for min/max absolute air mass to spectral_factor_firstsolar() . ( GH2086 , GH2100 )

Add roll_utc_offset and coerce_year arguments to get_pvgis_tmy() to allow user to specify time zone, rotate indices of TMY to begin at midnight, and force indices to desired year. ( GH2139 , GH2138 )

Restructured the pvlib/spectrum folder by breaking up the contents of pvlib/spectrum/mismatch.py into pvlib/spectrum/mismatch.py, pvlib/spectrum/irradiance.py, and pvlib/spectrum/response.py. ( GH2125 , GH2136 , GH2151 )

Added function for calculating wind speed at different heights, windspeed_powerlaw() . ( GH2118 , GH2124 )

delta_t can now be specified with an array in the SPA functions. The numba implementation now also allows calculation of delta_t internally. ( GH2189 , GH2190 )

The multithreaded SPA functions no longer emit a warning when calculating solar positions for short time series. ( GH2170 )

Implemented closed-form solution for alpha in detect_clearsky() , obviating the call to scipy.optimize, which was prone to runtime errors, and minimizing computation. ( GH2171 , GH2216 , GH2217 ).

Bug fixes

To prevent simulation output from differing slightly based on the time zone of the time stamps, models that use day of year for sun position and irradiance calculations now determine the day of year according to the UTC equivalent of the specified time stamps. The following functions are affected: lookup_linke_turbidity() , get_extra_radiation() , disc() , dirint() , spectrl2() . ( GH2054 , GH2055 )

hour_angle() and sun_rise_set_transit_geometric() now raise ValueError when given timezone-naive inputs, instead of assuming UTC. ( GH2055 )

Testing

Updated the tests for get_pvgis_tmy() and read_pvgis_tmy() as the default API endpoint has changed from 5.1 to 5.2. ( GH2222 )

Removed unused times input from dni_et fixture. ( GH2105 , GH2156 )

Documentation

Added new gallery example pages for:

Demonstrating the application of several spectral mismatch factor models. ( GH2107 , GH2114 )

Demonstrating the application of average_photon_energy() . ( GH2194 , GH2206 )

Calculating cell temperature for floating PV. ( GH2110 )

Demonstrating how to use different Perez coefficients in a ModelChain. ( GH2127 , GH2148 )

Fixed examples in shaded_fraction1d() . ( GH2215 )

Updated model description, added equation variable definitions, and created a new “notes” section in haydavies() and klucher() . ( GH2183 , GH2191 , GH2192 )

Document units with Wm⁻² instead of W/m^2 throughout pvlib.irradiance . ( GH2205 , GH2191 )

Split the contributing page into several pages. ( GH2210 , GH2219 )

Requirements

Python 3.9 or greater. ( GH2213 )

Minimum numpy version increased to v1.19.3. ( GH2213 )

Contributors

Echedey Luis ( @echedey-ls )

Yunho Kee ( @yhkee0404 )

Chris Deline ( @cdeline )

Ioannis Sifnaios ( @IoannisSifnaios )

Leonardo Micheli ( @lmicheli )

Rajiv Daxini ( @RDaxini )

Mark A. Mikofski ( @mikofski )

Ben Pierce ( @bgpierc )

Jose Meza ( @JoseMezaMendieta )

Kevin Anderson ( @kandersolar )

Luiz Reis ( @luizreiscver )

Carlos Cárdenas-Bravo ( @cardenca )

Marcos R. Escudero ( @marc-resc )

Bernat Nicolau ( @BernatNicolau )

Eduardo Sarquis ( @EduardoSarquis )

Adam R. Jensen ( @AdamRJensen )

Andrew B Godbehere ( @agodbehere )

Cliff Hansen ( @cwhanse )

Anton Driesse ( @adriesse )

Miguel Angel Sevillano Bendezú ( @msevillanob )

Erfan ( @Metal-Bat )

Will Holmgren ( @wholmgren )

Kurt Rhee ( @kurt-rhee )

@PhilBrk8

Mark Campanelli ( @markcampanelli )

Breaking changes

The deprecated pvlib.modelchain.basic_chain has now been removed. ( GH1862 )

Remove the poa_horizontal_ratio function and all of its references. ( GH1697 , GH2021 )

Updated MIDC_VARIABLE_MAP to reflect changes in instrumentation. ( GH2006 )

pvlib.iotools.read_srml_month_from_solardat was deprecated in v0.10.0 and has now been completely removed. The function is replaced by get_srml() . ( GH1779 , GH1989 )

The leap_day parameter in pvlib.iotools.get_psm3() now defaults to True instead of False. ( GH1481 , GH1991 )

pvlib.iotools.get_psm3() , pvlib.iotools.read_psm3() , and pvlib.iotools.parse_psm3() all now have map_variables=True by default. ( GH1425 , GH2094 )

The deprecated ivcurve_pnts parameter of pvlib.pvsystem.singlediode() is removed. Use pvlib.pvsystem.v_from_i() and pvlib.pvsystem.i_from_v() instead. ( GH2101 )

Deprecations

The pvlib.irradiance.SURFACE_ALBEDOS dictionary has been moved to pvlib.albedo.SURFACE_ALBEDOS . ( GH2095 )

Function pvlib.spectrum.get_am15g() has been deprecated in favor of the new function pvlib.spectrum.get_reference_spectra() . Use pvlib.spectrum.get_reference_spectra(standard="ASTM G173-03")["global"] instead. ( GH2039 )

Enhancements

Add a simple transformer efficiency model pvlib.transformer.simple_efficiency() . ( GH1269 , GH2053 )

Add function pvlib.shading.shaded_fraction1d() , to calculate the shade perpendicular to axis_azimuth . The function is applicable to both fixed-tilt and one-axis tracking systems. ( GH1689 , GH1725 , GH1962 )

Add function pvlib.albedo.inland_water_dvoracek() , to calculate the albedo for inland water bodies. ( GH2079 )

Added conversion functions from spectral response ([A/W]) to quantum efficiency ([unitless]) and vice versa. The conversion functions are pvlib.spectrum.sr_to_qe() and pvlib.spectrum.qe_to_sr() respectively. ( GH2040 , GH2041 )

Add function pvlib.spectrum.spectral_factor_pvspec() , which calculates the spectral mismatch factor as a function of absolute airmass and clearsky index using the PVSPEC model. ( GH1950 , GH2065 , GH2072 )

Add function pvlib.spectrum.spectral_factor_jrc() , which calculates the spectral mismatch factor as a function of airmass and clearsky index using the JRC model. ( GH1950 , GH2065 , GH2087 , GH2088 )

Added extraterrestrial and direct spectra of the ASTM G173-03 standard with the new function pvlib.spectrum.get_reference_spectra() . ( GH1963 , GH2039 )

Added function pvlib.shading.direct_martinez() to calculate shading losses by taking into account the amount of bypass diodes of a module. ( GH2063 , GH2070 )

Add function pvlib.irradiance.diffuse_par_spitters() to calculate the diffuse fraction of Photosynthetically Active Radiation (PAR) from the global diffuse fraction and the solar zenith. ( GH2047 , GH2048 )

Default altitude in pvlib.location.Location now comes from lookup_altitude() ( GH1516 , GH1850 )

Documentation

Configure mathjax to left-align and indent equations in docstrings. ( GH2056 )

Contributors

Cliff Hansen ( @cwhanse )

Kurt Rhee ( @kurt-rhee )

Mark Mikofski ( @mikofski )

Siddharth Kaul ( @k10blogger )

Ioannis Sifnaios ( @IoannisSifnaios )

Mark Campanelli ( @markcampanelli )

Rajiv Daxini ( @RDaxini )

Nicolas Martinez ( @nicomt )

@PhilBrk8

John Obrecht ( @jmobrecht )

Echedey Luis ( @echedey-ls )

Adam R. Jensen ( @AdamRJensen )

Anton Driesse ( @adriesse )

Will Holmgren ( @wholmgren )

Will Hobbs ( @williamhobbs )

Kevin Anderson ( @kandersolar )

Bug fixes

Compatibility with numpy 2.0. ( GH2026 , GH2027 )

Improved reliability of pvlib.singlediode.bishop88_mpp() , pvlib.singlediode.bishop88_i_from_v() and pvlib.singlediode.bishop88_v_from_i() by improving the initial guess for the newton and brentq algorithms. ( GH2013 , GH2032 )

Corrected equation for Ixx0 in pvlib.pvsystem.sapm() . ( GH2016 , GH2019 )

Fixed pvlib.pvsystem.retrieve_sam() silently ignoring the path parameter when name was provided. Now an exception is raised requesting to only provide one of the two parameters. ( GH2018 , GH2020 )

Documentation

Fix variable name typo at docs\examples\system-models\plot_oedi_9068.py . ( GH1996 )

Remove “Comparison with PVLib for Matlab” page from the User Guide. ( GH2010 , GH2012 )

Requirements

Minimum version of Python increased from 3.7 to 3.8. ( GH1975 , GH2029 )

Minimum version of scipy advanced from 1.5.0 to 1.6.0. ( GH2027 )

Contributors

Cliff Hansen ( @cwhanse )

@apct69

Mark Mikofski ( @mikofski )

Echedey Luis ( @echedey-ls )

Adam R. Jensen ( @adamrjensen )

Anton Driesse ( @adriesse )

Scott Meredith ( @smmeredith )

Alexander Morgan ( @alexandermorgan )

Kevin Anderson ( @kandersolar )

Enhancements

Added the Huld PV model used by PVGIS ( GH1940 )

Add get_solargis() for retrieving Solargis irradiance data. ( GH1969 )

Added function pvlib.shading.projected_solar_zenith_angle() , a common calculation in shading and tracking. ( GH1734 , GH1904 )

Added get_solrad() for fetching irradiance data from the SOLRAD ground station network. ( GH1967 )

Added metadata parsing to read_solrad() to follow the standard iotools convention of returning a tuple of (data, meta). Previously the function only returned a dataframe. ( GH1968 )

Bug fixes

Fixed an error in solar position calculations when using pandas.DatetimeIndex with unit other than 'ns' ( GH1932 ). The following functions were affected:

ModelChain and get_solarposition() with the nrel_numpy and nrel_numba methods

spa_python()

sun_rise_set_transit_spa()

nrel_earthsun_distance()

hour_angle()

sun_rise_set_transit_geometric()

ModelChain now raises a more useful error when temperature_model_parameters are specified on the passed system instead of on its arrays . ( GH1759 ).

pvlib.irradiance.ghi_from_poa_driesse_2023() now correctly makes use of the xtol argument. Previously, it was ignored. ( GH1970 , GH1971 )

Fixed incorrect unit conversion of precipitable water used for the Solcast iotools functions. ( GH1969 )

infer_temperature_model now raises a more useful error when the temperature model cannot be inferred ( GH1946 )

The default URL for retrieving irradiance data from the SRML network was updated in get_srml() ( GH1957 , GH1922 )

Documentation

Improved references and description for get_ground_diffuse() . ( GH1883 , GH1953 )

Fixed broken URLs in various places. ( GH1957 , GH1960 )

Added a gallery example with a model for OEDI system 9068. ( GH1985 )

Requirements

Minimum version of pandas advanced from 0.25.0 to 1.3.0. ( GH1969 )

Minimum version of numpy advanced from 1.16.0 to 1.17.3. ( GH1969 )

Contributors

Patrick Sheehan ( @patricksheehan )

Echedey Luis ( @echedey-ls )

Kevin Anderson ( @kandersolar )

Cliff Hansen ( @cwhanse )

Roma Koulikov ( @matsuobasho )

Adam R. Jensen ( @AdamRJensen )

Peter Dudfield ( @peterdudfield )

Anton Driesse ( @adriesse )

Mark Mikofski ( @mikofski )

Will Holmgren ( @wholmgren )

Jules Chéron ( @jules-ch )

Enhancements

Added the continuous Perez-Driesse transposition model. pvlib.irradiance.perez_driesse() ( GH1841 , GH1876 )

Added a reverse transposition algorithm using the Perez-Driesse model. pvlib.irradiance.ghi_from_poa_driesse_2023() ( GH1901 , GH1907 )

pvlib.bifacial.infinite_sheds.get_irradiance() and pvlib.bifacial.infinite_sheds.get_irradiance_poa() now include shaded fraction in returned variables. ( GH1871 )

Added get_solcast_tmy() , get_solcast_historic() , get_solcast_forecast() and get_solcast_live() to read data from the Solcast API. ( GH1313 , GH1875 )

Added convert() and fit() that convert between IAM models, and that fit an IAM model to data. ( GH1824 , GH1827 )

Add pvlib.iotools.read_solaranywhere() and pvlib.iotools.get_solaranywhere() for reading and retrieving SolarAnywhere solar irradiance data. ( GH1497 , GH1310 )

Bug fixes

Fixed CAMS error message handler in pvlib.iotools.get_cams() . ( GH1799 , GH1905 )

Fix mapping of the dew point column to temp_dew when map_variables is True in pvlib.iotools.get_psm3() . ( GH1920 )

Fix pvlib.modelchain.ModelChain to use attribute clearsky_model . ( GH1924 )

Testing

Replace use of deprecated pkg_resources . ( GH1881 , GH1882 )

Added Python 3.12 to test suite. ( GH1886 )

Documentation

Create Weather data User’s Guide page. ( GH1754 )

Fixed a plotting issue in the IV curve gallery example. ( GH1895 )

Added two examples to demonstrate reverse transposition. ( GH1907 )

Fixed detect_clearsky() example in Clear sky . ( GH1914 )

Clarified purpose of ModelChain.clearsky_model . ( GH1924 )

Requirements

Minimum version of scipy advanced from 1.4.0 to 1.5.0. ( GH1918 , GH1919 )

Contributors

Arjan Keeman ( @akeeman )

Miguel Sánchez de León Peque ( @Peque )

Will Hobbs ( @williamhobbs )

Anton Driesse ( @adriesse )

Abigail Jones ( @ajonesr )

Cliff Hansen ( @cwhanse )

Gilles Fischer ( @GillesFischerV )

Adam R. Jensen ( @AdamRJensen )

@matsuobasho

Harry Jack ( @harry-solcast )

Kevin Anderson ( @kandersolar )

Lorenzo Riches ( @lorenzo-solcast )

Hugh Cutcher ( @hugh-solcast )

Echedey Luis ( @echedey-ls )

Will Holmgren ( @wholmgren )

Miroslav Šedivý ( @eumiro )

Mark Mikofski ( @mikofski )

Phoebe Pearce ( @phoebe-p )

Eva-Maria Grommes ( @EwaGomez )

Enhancements

Added .pan/.ond reader function pvlib.iotools.read_panond() . ( GH1747 , GH1749 )

Added support for dates to be specified as strings in the iotools get functions: get_pvgis_hourly() , get_cams() , get_bsrn() , and read_midc_raw_data_from_nrel() . ( GH1800 )

Added support for asymmetric limiting angles in pvlib.tracking.singleaxis() and SingleAxisTrackerMount . ( GH1777 , GH1809 , GH1852 )

Added option to infer threshold values for pvlib.clearsky.detect_clearsky() ( GH1808 , GH1784 )

Added a continuous version of the Erbs diffuse-fraction/decomposition model. pvlib.irradiance.erbs_driesse() ( GH1755 , GH1834 )

Added interp() option as AOI losses model in ModelChain and PVSystem . ( GH1742 , GH1832 )

PVSystem objects with a single Array can now be created without wrapping the Array in a list first. ( GH1831 , GH1854 )

Bug fixes

pvlib.iotools.get_psm3() no longer incorrectly returns clear-sky DHI instead of clear-sky GHI when requesting ghi_clear . ( GH1819 )

pvlib.singlediode.bishop88() with method='newton' no longer crashes when passed pandas.Series of length one. ( GH1787 , GH1822 )

PVSystem now correctly passes n_ar module parameter to pvlib.iam.physical() when this IAM model is specified or inferred. ( GH1832 )

Testing

Added GitHub action to lint file changes with Flake8, replacing Stickler-CI. ( GH776 , GH1722 , GH1723 , GH1786 )

Documentation

Added docstring detail for pvlib.iam.schlick_diffuse() . ( GH1811 , GH1812 )

Specified that pvlib.singlediode.bishop88() , pvlib.singlediode.bishop88_i_from_v() , and pvlib.singlediode.bishop88_v_from_i() parameters breakdown_factor , breakdown_voltage , and breakdown_exp should be floats. ( GH1820 , GH1821 )

Fix and update example in pvlib.pvsystem.retrieve_sam() . ( GH1741 , GH1833 )

Fix error in pvlib.iotools.get_pvgis_hourly() documentation of surface_azimuth . ( GH1724 , GH1838 )

Update definition of snow_events parameter for pvlib.snow.loss_townsend() . ( GH1839 , GH1840 )

Added gallery example demonstrating how horizon profile data from pvlib.iotools.get_pvgis_horizon() , can be used to apply horizon shading to time series dni and global poa data. ( GH1849 )

Contributors

Connor Krening ( @ckrening )

Adam R. Jensen ( @AdamRJensen )

Michal Arieli ( @MichalArieli )

Abigail Jones ( @ajonesr )

Taos Transue ( @reepoi )

Echedey Luis ( @echedey-ls )

Todd Karin ( @toddkarin )

NativeSci ( @nativesci )

Anton Driesse ( @adriesse )

Lukas Grossar ( @tongpu )

Areeba Turabi ( @aturabi )

Saurabh Aneja ( @spaneja )

Miroslav Šedivý ( @eumiro )

kjsauer ( @kjsauer )

Jules Chéron ( @jules-ch )

Cliff Hansen ( @cwhanse )

Will Holmgren ( @wholmgren )

Mark Mikofski ( @mikofski )

Kevin Anderson ( @kandersolar )

To resolve an installation issue with pvfactors and shapely , this release drops the optional pvfactors dependency and replaces it with solarfactors , a fork of pvfactors maintained by the pvlib community. This change should not affect any user code. ( GH1796 , GH1797 , GH1657 )

Breaking changes

After being deprecated for over a year, the pvlib.forecast module is now removed entirely. ( GH1766 )

The following, originally deprecated in v0.9.0 (September 1, 2021) , is now removed: ( GH1770 )

The pvlib.tracking.SingleAxisTracker class

The various model-specific PVSystem inverter and cell temperature methods

Attribute “pass-through” from ModelChain to ModelChainResult

Attribute “pass-through” from PVSystem to Array

The eta_m parameter in pvlib.temperature.pvsyst_cell()

Reorder arguments of pvlib.pvsystem.PVSystem.i_from_v() , pvlib.pvsystem.i_from_v() , pvlib.pvsystem.v_from_i() , pvlib.singlediode._lambertw_i_from_v() , and pvlib.singlediode._lambertw_v_from_i() to match pvlib.pvsystem.singlediode() . ( GH1718 , GH1719 )

Map wind direction to 'wind_direction' instead of 'wind_dir' in pvlib.iotools.read_srml() and pvlib.iotools.read_srml_month_from_solardat ( GH1773 )

get_pvgis_tmy() and read_pvgis_tmy() now rename columns to standard pvlib names by default ( map_variables=True ) ( GH1772 )

In get_pvgis_tmy() , the map_variables keyword parameter now comes before the url keyword parameter. ( GH1795 )

Modified the surface_azimuth parameter in pvlib.iotools.get_pvgis_hourly() to conform to the pvlib azimuth convention (counterclockwise from north). Previously 0 degrees represented south. ( GH1724 , GH1739 )

For consistency with the rest of pvlib, the pw parameters are renamed to precipitable_water in pvlib.spectrum.spectral_factor_firstsolar() . ( GH1768 )

For consistency with the rest of pvlib, the tilt parameter is renamed to surface_tilt in pvlib.soiling.hsu() . ( GH1717 , GH1738 )

Several undocumented functions in pvlib.iotools.midc , pvlib.iotools.srml , and pvlib.iotools.surfrad are now private. ( GH1756 , GH1769 )

Deprecations

The ivcurve_pnts parameter of pvlib.pvsystem.singlediode() is deprecated. Use pvlib.pvsystem.v_from_i() and pvlib.pvsystem.i_from_v() instead. ( GH1626 , GH1743 )

Functions for calculating spectral modifiers have been moved to pvlib.spectrum : pvlib.atmosphere.first_solar_spectral_correction() is deprecated and replaced by spectral_factor_firstsolar() , and pvlib.pvsystem.sapm_spectral_loss() is deprecated and replaced by spectral_factor_sapm() . ( GH1628 )

Removed the get_ecmwf_macc and read_ecmwf_macc iotools functions as the MACC dataset has been removed by ECMWF (data period 2003-2012). Instead, ECMWF recommends to use CAMS global reanalysis (EAC4) from the Atmosphere Data Store (ADS). See also pvlib.iotools.get_cams() . ( GH1691 , GH1654 )

The recolumn parameter in pvlib.iotools.read_tmy3() , which maps TMY3 column names to nonstandard alternatives, is now deprecated. We encourage using map_variables (which produces standard pvlib names) instead. ( GH1517 , GH1623 )

pvlib.iotools.read_srml_month_from_solardat is deprecated and replaced by pvlib.iotools.get_srml() . ( GH1779 )

Enhancements

Added two new irradiance decomposition models: pvlib.irradiance.orgill_hollands() ( GH1730 ) and pvlib.irradiance.louche() ( GH1705 ).

The return values of pvlib.pvsystem.calcparams_desoto() , pvlib.pvsystem.calcparams_cec() , and pvlib.pvsystem.calcparams_pvsyst() are all numeric types and have the same Python type as the effective_irradiance and temp_cell parameters. ( GH1626 , GH1700 )

Added map_variables parameter to pvlib.iotools.read_tmy3() ( GH1517 , GH1623 ), pvlib.iotools.read_srml() , and pvlib.iotools.read_srml_month_from_solardat ( GH1773 ).

Added pvlib.iotools.get_srml() that is similar to pvlib.iotools.read_srml_month_from_solardat but is able to fetch multiple months of data using the start and end parameters. ( GH1779 )

Allow passing keyword arguments to scipy.optimize.brentq() and scipy.optimize.newton() solvers in bishop88_mpp() , bishop88_i_from_v() and bishop88_v_from_i() . Among others, tolerance and number of iterations can be set. ( GH1249 , GH1764 )

Improved ModelChainResult.repr ( GH1236 )

Exposes several functions useful for bifacial and shading calculations ( GH1666 ):

pvlib.bifacial.utils.vf_row_sky_2d()

pvlib.bifacial.utils.vf_row_sky_2d_integ()

pvlib.bifacial.utils.vf_row_ground_2d()

pvlib.bifacial.utils.vf_row_ground_2d_integ()

pvlib.bifacial.utils.vf_ground_sky_2d()

pvlib.bifacial.utils.vf_ground_sky_2d_integ()

pvlib.shading.ground_angle()

Added a function pvlib.spectrum.spectral_factor_caballero() to estimate spectral mismatch modifiers from atmospheric conditions. ( GH1296 )

Add optional encoding parameter to pvlib.iotools.read_tmy3() . ( GH1732 , GH1737 )

Added function to retrieve horizon data from PVGIS pvlib.iotools.get_pvgis_horizon() . ( GH1290 , GH1395 )

Update the URL used in the pvlib.iotools.get_cams() function. The new URL supports load-balancing and redirects to the fastest server. ( GH1688 , GH1740 )

pvlib.iotools.get_psm3() now has a url parameter to give the user the option of controlling what NSRDB endpoint is used. ( GH1736 )

pvlib.iotools.get_psm3() now uses the new NSRDB 3.2.2 endpoint for hourly and half-hourly single-year datasets. ( GH1591 , GH1736 )

The default solar position algorithm (NREL SPA) is now 50-100% faster. ( GH1748 )

Added functions to retrieve daily precipitation, temperature, and snowfall data from the NOAA’s ACIS service: get_acis_prism() , get_acis_nrcc() , get_acis_mpe() , get_acis_station_data() , and get_acis_available_stations() . ( GH1293 , GH1767 )

Bug fixes

Prevent small negative values of v_oc in pvlib.singlediode._lambertw() which result from accumulated roundoff error. ( GH1780 , GH1673 , GH1782 )

Corrects an error in view factor calculations which are part of pvlib.bifacial.infinite_sheds.get_irradiance() . The error affects rear surface irradiance by a few W/m2. As part of the correction, average view factors are now computed by exact formulas rather than by numerical integration. ( GH1665 , GH1666 )

data can no longer be left unspecified in pvlib.modelchain.ModelChain.run_model_from_effective_irradiance() . ( GH1713 , GH1720 )

d2mutau and NsVbi are now correctly passed through pvlib.pvsystem.max_power_point() instead of being hardcoded. ( GH1733 )

pvlib.iam.physical() no longer returns NaN when n=1 and aoi>90 . This bug was introduced in v0.9.5. ( GH1706 , GH1707 )

Testing

Migrated to mamba-org/setup-micromamba. ( GH1746 , GH1758 )

Documentation

Updated the description of the interval parameter in pvlib.iotools.get_psm3() . ( GH1702 , GH1712 )

Fixed outdated nbviewer links. ( GH1721 , GH1726 )

Requirements

With the removal of pvlib.forecast , the following packages are no longer listed as (optional) dependencies: netCDF4 , cftime , and siphon . ( GH1766 )

Contributors

Taos Transue ( @reepoi )

Nicholas Riedel-Lyngskær ( @nicorie )

Adam R. Jensen ( @AdamRJensen )

Echedey Luis ( @echedey-ls )

Cliff Hansen ( @cwhanse )

Cédric Leroy ( @cedricleroy )

Jean-Baptiste Pasquier ( @pasquierjb )

Mark Mikofski ( @mikofski )

Lakshya Garg ( @Lakshyadevelops )

Ben Pierce ( @bgpierc )

Joseph Palakapilly ( @JPalakapillyKWH )

Anton Driesse ( @adriesse )

Will Holmgren ( @wholmgren )

Karel De Brabandere ( @kdebrab )

Josh Stein ( @jsstein )

Kevin Anderson ( @kandersolar )

Siddharth Kaul ( @k10blogger )

Kshitiz Gupta ( @kshitiz305 )

Stefan de Lange ( @langestefan )

Jose Antonio Caballero ( @Jacc0027 )

Andy Lam ( @andylam598 )

@ooprathamm

Devon Watt ( @d-watt )

Todd Karin ( @toddkarin )

Corey Pullium ( @cpullium )

Starting with this version, new releases are no longer distributed through the pvlib conda channel . We recommend conda users install from the conda-forge channel instead (see Installation ).

Enhancements

Added the optional string_factor parameter to pvlib.snow.loss_townsend() . ( GH1636 , GH1653 )

Added optional n_ar parameter to pvlib.iam.physical() to support an anti-reflective coating. ( GH1501 , GH1616 )

boland() is another diffuse fraction, DF, estimation method similar to Erbs but uses a single logistic exponential correlation between DF and clearness index, kt, that is continuously differentiable and bounded between zero and one. ( GH1179 )

Add model='gueymard2003' , the airmass model used for REST and REST2, to get_relative_airmass() . ( GH1655 )

Added an optional model parameter to pvlib.bifacial.infinite_sheds.get_irradiance() and pvlib.bifacial.infinite_sheds.get_irradiance_poa() to enable use of the hay-davies sky diffuse irradiance model instead of the default isotropic model. ( GH1668 )

Added an optional vectorize parameter to pvlib.bifacial.infinite_sheds.get_irradiance() and pvlib.bifacial.infinite_sheds.get_irradiance_poa() which, when set to True , enables faster calculation but with increased memory usage. ( GH1680 , GH1682 )

Update the ADR inverter model parameter database by appending the ADR equivalents of all inverters in the current (2019) Sandia inverter model parameter database. ( GH1695 )

Use Horner’s Method to evaluate polynomials in disc() , may decrease runtime by 20%. ( GH1180 , GH1183 )

Bug fixes

Added a limit to pvlib.snow.loss_townsend() to guard against incorrect loss results for systems that are near the ground. ( GH1636 , GH1653 )

Fixed incorrect mapping of requested parameters names when using pvlib.iotools.get_psm3() . Also fixed the random reordering of the dataframe columns. ( GH1629 , GH1647 , GH1648 )

When using utc_time_range with pvlib.iotools.read_ecmwf_macc() , the time index subset is now selected with nearest instead of before and after for consistency with cftime>=1.6.0 . ( GH1609 , GH1656 )

pvsyst_temperature_coeff() no longer raises a scipy deprecation warning (and is slightly more accurate). ( GH1644 , GH1674 )

Testing

Added Python 3.11 to test suite. ( GH1582 )

Updated PSM3 test data files to match the new version 3.2.2 data returned by the PSM3 API. ( GH1591 , GH1652 )

Testing pvlib.pvsystem.singlediode() , pvlib.pvsystem.v_from_i() , and pvlib.pvsystem.i_from_v() against precisely generated IV curve data. ( GH411 , GH1573 )

Documentation

Remove LGTM.com integration. ( GH1550 , GH1651 )

Benchmarking

Added benchmarks for pvlib.bifacial.infinite_sheds . ( GH1627 )

Requirements

Removed unnecessary nose test requirement. ( GH1637 )

Contributors

Kevin Anderson ( @kanderso-nrel )

Will Holmgren ( @wholmgren )

Cliff Hansen ( @cwhanse )

Adam R. Jensen ( @adamrjensen )

Pratham Chauhan ( @ooprathamm )

Karel De Brabandere ( @kdebrab )

Mark Mikofski ( @mikofski )

Anton Driesse ( @adriesse )

Michael Deceglie ( @mdeceglie )

Saurabh Aneja ( @spaneja )

John Moseley ( @johnMoseleyArray )

Areeba Turabi ( @aturabi )

Mark Campanelli ( @markcampanelli )

Taos Transue ( @reepoi )

Tim Townsend

Tom Arjannikov ( @Arjannikov )

Enhancements

Multiple code style issues fixed that were reported by LGTM analysis. ( GH1275 , GH1559 )

Added a direct IAM model pvlib.iam.schlick() which can be used with marion_diffuse() , and a diffuse IAM model pvlib.iam.schlick_diffuse() . ( GH1562 , GH1564 )

Added a function to calculate one of GHI, DHI, and DNI from values of the other two. complete_irradiance() . ( GH1565 , GH1567 )

Added optional return_components parameter to pvlib.irradiance.haydavies() to return individual diffuse irradiance components. ( GH1553 , GH1568 )

Added a module temperature model that accounts for radiative losses to the sky in a simplified way, using the Faiman model as an example. faiman_rad() ( GH1594 , GH1595 )

Added a function pvlib.ivtools.utils.astm_e1036() to perform ASTM E1036 extraction of IV curve parameters. ( GH1585 )

Added the ADR PV module efficiency model and a function to find its parameters from field or lab measurements ( pvefficiency_adr() and fit_pvefficiency_adr() ). ( GH1544 , GH1602 )

Bug fixes

Fixed bug in pvlib.shading.masking_angle() and pvlib.bifacial.infinite_sheds._ground_angle() where zero gcr input caused a ZeroDivisionError. ( GH1576 , GH1589 )

Fixed bug in pvlib.tools._golden_sect_DataFrame() so that a result is returned when the search interval is length 0 (which occurs in pvlib.pvsystem.singlediode() if v_oc is 0.) ( GH1603 , GH1606 )

Testing

Corrected a flawed test for get_ground_diffuse() . ( GH1569 , GH1575 )

Documentation

Added an FAQ page to the docs: Frequently Asked Questions . ( GH1546 , GH1549 )

Fixed equation in pvlib.iam.martin_ruiz() docstring. ( GH1561 , GH1599 )

Fixed an error in pvlib.singlediode.bishop88_mpp() docstring. ( GH1613 , GH1615 )

Added three gallery examples demonstrating how the new ADR PV model can be used for time series simulation. ( GH1544 , GH1602 )

Benchmarking

Removed time_tracker_singleaxis function from tracking.py. ( GH1508 , GH1535 )

Requirements

Minimum version of scipy advanced from 1.2.0 to 1.4.0. ( GH483 , GH1617 )

Contributors

Kirsten Perry ( @kperrynrel )

Christian Orner ( @chrisorner )

Saurabh Aneja ( @spaneja )

Marcus Boumans ( @bowie2211 )

Michael Deceglie ( @mdeceglie )

Yu Xie ( @xieyupku )

Anton Driesse ( @adriesse )

Cliff Hansen ( @cwhanse )

Kevin Anderson ( @kanderso-nrel )

Karel De Brabandere ( @kdebrab )

Naman Priyadarshi ( @Naman-Priyadarshi )

Adam R. Jensen ( @AdamRJensen )

Echedey Luis ( @echedey-ls )

Mark Mikofski ( @mikofski )

Mark Campanelli ( @markcampanelli )

Will Holmgren ( @wholmgren )

@avarf

Marios Theristis ( @mtheristis )

Enhancements

New class and function translate module temperature model parameters GenericLinearModel() generic_linear() ( GH1442 , GH1463 )

Low resolution altitude lookup map lookup_altitude() ( GH1516 , GH1518 )

New module to calculate spectral mismatch from field spectral measurements get_example_spectral_response() pvlib.spectrum.get_am15g() calc_spectral_mismatch_field() ( GH1523 , GH1524 )

Added Townsend-Powers monthly snow loss model: pvlib.snow.loss_townsend() ( GH1246 , GH1251 , GH1468 )

Documentation

Clarified description of cross-axis slope in pvlib.tracking ( GH1530 )

Removed the kwarg closed from pd.date_range in the examples since it is deprecated for pandas >= 1.4.0. ( GH1540 )

Contributors

João Guilherme ( @joaoguilhermeS )

Nicolas Martinez ( @nicomt )

Anton Driesse ( @adriesse )

Cliff Hansen ( @cwhanse )

Kevin Anderson ( @kanderso-nrel )

Mark Mikofski ( @mikofski )

Will Holmgren ( @wholmgren )

Mark Campanelli ( @markcampanelli )

Adam R. Jensen ( @AdamRJensen )

Abhishek Parikh ( @abhisheksparikh )

Taos Transue ( @reepoi )

( @chiragpachori )

Enhancements

albedo can now be provided as a column in the weather DataFrame input to pvlib.modelchain.ModelChain.run_model() . ( GH1387 , GH1478 )

albedo is now available as an input to pvlib.pvsystem.PVSystem.get_irradiance() and pvlib.pvsystem.Array.get_irradiance() . ( GH1478 )

pvlib.iotools.read_surfrad() now also accepts remote files with https links in addition to files on the SURFRAD FTP server. ( GH1459 )

Add pvlib.tracking.calc_surface_orientation() for calculating single-axis tracker surface_tilt and surface_azimuth from rotation angles. ( GH1471 , GH1480 )

Improve error message about uneven time intervals for detect_clearsky() and prilliman() . ( GH1476 , GH1490 )

Add support for PEP517 & PEP518 with setuptools build backend. ( GH1495 )

Bug fixes

pvlib.irradiance.get_total_irradiance() and pvlib.solarposition.spa_python() now raise an error instead of silently ignoring unknown parameters. ( GH1437 )

Fix a bug in pvlib.solarposition.sun_rise_set_transit_ephem() where passing localized timezones with large UTC offsets could return rise/set/transit times for the wrong day in recent versions of ephem . ( GH1449 , GH1448 )

pvlib.iotools.read_tmy3() is now able to accept midnight timestamps as either 24:00 (which is the standard) as well as 00:00. Previously 00:00 timestamps would incorrectly be moved one day forward. ( GH1494 )

pvlib.iotools.get_psm3() now raises a deprecation warning if the leap_day parameter is not specified in a single-year request. Starting in pvlib 0.11.0 leap_day will default to True instead of False. ( GH1481 , GH1511 )

Testing

Switched CI testing provider from Azure to GitHub Actions. ( GH1306 )

Speed up CI setup using micromamba instead of conda. ( GH1493 )

Drop python 3.6 (reached end of life Dec 2021) and add 3.10 to test matrix. ( GH1507 )

Documentation

Added a reference to pvlib.inverter.sandia_multi() . ( GH1479 )

Add gallery example of simulating rearside irradiance for a fixed-tilt array with pvfactors. ( GH1470 )

Updated reference links to CAMS Radiation. ( GH1515 , GH1529 )

Benchmarking

Updated version of numba in asv.conf from 0.36.1 to 0.40.0 to solve numba/numpy conflict. ( GH1439 , GH1440 )

Added benchmarks for the pvlib.scaling module. ( GH1445 )

Added a basic CI asv check. ( GH1446 , GH1454 )

Requirements

Python 3.7 or greater. ( GH1507 )

Minimum pandas version increased to v0.25.0, released July 18, 2019. ( GH1448 )

Contributors

Adam R. Jensen ( @AdamRJensen )

Naman Priyadarshi ( @Naman-Priyadarshi )

Chencheng Luo ( @roger-lcc )

Prajwal Borkar ( @PrajwalBorkar )

Cliff Hansen ( @cwhanse )

Kevin Anderson ( @kanderso-nrel )

Cliff Hansen ( @cwhanse )

Jules Chéron ( @jules-ch )

Kurt Rhee ( @kurt-rhee )

Will Hobbs ( @williamhobbs )

Stephen Schneider ( @sjschneider )

@Kaesekopf

@hf-kklein

Mark Campanelli ( @campanelli-sunpower )

Anton Driesse ( @adriesse )

Kristen Wagner ( @kwagnercpr )

Mark Mikofski ( @mikofski )

Deprecations

Moved pvlib.bifacial.pvfactors_timeseries() to pvlib.bifacial.pvfactors.pvfactors_timeseries() . pvlib.bifacial is now a sub-package. ( GH717 )

pvlib.modelchain.basic_chain is deprecated. See pvlib.modelchain.ModelChain.with_pvwatts() and pvlib.modelchain.ModelChain.with_sapm() for alternative simplified ModelChain interfaces, although note that the inputs do not directly translate. ( GH1401 )

All functionality in the pvlib.forecast module is deprecated. For details, see forecasts . ( GH1057 , GH1426 )

Enhancements

Added map_variables option to pvlib.iotools.get_psm3() and pvlib.iotools.read_psm3() ( GH1374 )

Added pvlib.bifacial.infinite_sheds , containing a model for irradiance on front and back surfaces of bifacial arrays. ( GH717 )

Added map_variables option to read_crn() ( GH1368 )

Added pvlib.temperature.prilliman() for modeling cell temperature at short time steps ( GH1081 , GH1391 )

Bug fixes

Address round-off effects in pvlib.ivtools.utils._schumaker_qspline() ( GH1311 , GH1315 )

Fixed a bug in pvlib.spectrum.spectrl2() where negative spectral irradiance values were returned when the sun is behind the plane of array ( GH1348 , GH1349 )

Fixed bug in pvlib.iotools.get_pvgis_hourly() where the optimal_surface_tilt argument was not being passed to the optimalinclination request parameter ( GH1356 )

Fixed bug in pvlib.bifacial.pvfactors.pvfactors_timeseries() where scalar surface_tilt and surface_azimuth inputs caused an error ( GH1127 , GH1332 , GH1361 )

Added -99999 to list of values to map to nan in read_crn() ( GH1372 , GH1368 )

Changed the metadata entry for the wind speed unit to “Wind Speed Units” in the PSM3 iotools function ( GH1375 )

Improved convergence when determining the maximum power point using for pvlib.pvsystem.singlediode() with method='lambertw' . Tolerance is determined for the voltage at the maximum power point, and is improved from 0.01 V to 1e-8 V. ( GH1087 , GH1089 )

Testing

Updated test values to match the new values returned by the PVGIS TMY API. The difference is very minor (0.01 W/m2, affecting only a few beam irradiance values) ( GH1396 )

Documentation

Fix documentation return error in pvlib.forecast.ForecastModel.cloud_cover_to_transmittance_linear() ( GH1367 , GH1370 )

Add gallery example illustrating bifacial simulation using the pvlib.bifacial.pvfactors.pvfactors_timeseries() function and either pvlib.modelchain.ModelChain or procedural functions. ( GH1394 )

Fix some typos ( GH1414 )

Clarify the descriptions of delta_t in several solar position functions ( GH1429 )

Changed $C$ to $\degree C$ in the plot_singlediode.py file ( GH1434 )

Requirements

numpy >= 1.16.0 is now required for all python versions. ( GH1400 )

Fix an installation issue with dataclasses on python 3.6 ( GH1302 , GH1422 )

Contributors

Cliff Hansen ( @cwhanse )

@Antoine-0

@Carlosbogo

Christian Weickhmann ( @cweickhmann )

Kevin Anderson ( @kanderso-nrel )

Adam R. Jensen ( @AdamRJensen )

Johann Loux ( @JoLo90 )

Saurabh Aneja ( @spaneja )

Jack Kelly ( @JackKelly )

Somasree Majumder( @soma2000-lang )

Naman Priyadarshi ( @Naman-Priyadarshi )

Will Holmgren ( @wholmgren )

Mark Mikofksi ( @mikofski )

Will Hobbs ( @williamhobbs )

Uday Guntupalli ( @uguntupalli )

Shashwata Roy ( @RoyCoding8 )

Breaking changes

Moved functions related to inverters from pvsystem.py to inverter.py . Functions are renamed to follow a more consistent pattern, as follows ( GH886 , GH1136 ):

pvlib.pvsystem.snlinverter is now pvlib.inverter.sandia()

pvlib.pvsystem.pvwatts_ac is now pvlib.inverter.pvwatts()

pvlib.pvsystem.adrinverter is now pvlib.inverter.adr()

Argument ac_model for pvlib.modelchain.ModelChain now accepts 'sandia' , 'pvwatts' and 'adr' for the inverter models. ( GH886 , GH1136 )

Calling pvlib.pvsystem.PVSystem.sapm_celltemp() without setting PVSystem.temperature_model_parameters , or a valid combination of PVsystem.module_type and PVsystem.racking_model , will now raise an exception. ( GH1030 , GH1033 , GH1136 )

Deprecated arbitrary keyword arguments for pvlib.location.Location , pvlib.pvsystem.PVSystem , pvlib.tracking.SingleAxisTracker , and pvlib.modelchain.ModelChain . Supplying arbitrary keyword to these objects result in TypeErrors in v0.9. ( GH1029 , GH1053 , GH1136 )

pvlib.pvsystem.LocalizedPVSystem and pvlib.pvsystem.LocalizedSingleAxisTracker have been removed. Use pvlib.location.Location , pvlib.pvsystem.PVSystem , pvlib.tracking.SingleAxisTracker , and pvlib.modelchain.ModelChain instead. ( GH1029 , GH1034 , GH1053 , GH1136 )

irradiance.liujordan and ForecastModel.cloud_cover_to_irradiance_liujordan have been removed. ( GH1136 )

ModelChain.snlinverter changed to ModelChain.sandia_inverter . ModelChain.adrinverter changed to ModelChain.adr_inverter . ( GH1150 )

The orientation_strategy parameter has been removed from the various pvlib.modelchain.ModelChain constructors and surface_tilt , surface_azimuth are now required parameters for pvlib.modelchain.basic_chain ( GH1028 , GH1181 )

Removed the **kwargs parameters from sapm() and calcparams_desoto() and calcparams_cec() ( GH1118 , GH1222 )

Switched the order of the outputs from the PSM3 iotools, notably pvlib.iotools.get_psm3() and pvlib.iotools.read_psm3() ( GH1245 , GH1268 )

Changed the naming of the inputs startdate / enddate to start / end in get_ecmwf_macc() ( GH1245 , GH1268 )

Change the naming of the inputs lat / lon to latitude / longitude in get_pvgis_tmy() ( GH1245 , GH1268 )

Deprecations

The following ModelChain attributes are deprecated. They have been moved to the ModelChainResult class that is accessible via ModelChain.results :

ModelChain.ac

ModelChain.airmass

ModelChain.aoi

ModelChain.aoi_modifier

ModelChain.cell_temperature

ModelChain.dc

ModelChain.diode_params

ModelChain.effective_irradiance

ModelChain.losses

ModelChain.solar_position

ModelChain.spectral_modifier

ModelChain.total_irrad

ModelChain.tracking

ModelChain.weather

ModelChain.times

The following PVSystem cell temperature methods have been deprecated and consolidated into the new wrapper method get_cell_temperature() ( GH1211 ):

sapm_celltemp()

pvsyst_celltemp()

faiman_celltemp()

fuentes_celltemp()

noct_sam_celltemp()

The eta_m parameter for pvsyst_cell() is replaced by parameter module_efficiency . ( GH1188 , GH1218 )

The following attributes of pvlib.pvsystem.PVSystem and pvlib.tracking.SingleAxisTracker have been deprecated in favor of the corresponding pvlib.pvsystem.Array attributes:

PVSystem.albedo

PVSystem.module

PVSystem.module_parameters

PVSystem.module_type

PVSystem.modules_per_string

PVSystem.racking_model

PVSystem.strings_per_inverter

PVSystem.surface_tilt

PVSystem.surface_azimuth

PVSystem.temperature_model_parameters

The pvlib.tracking.SingleAxisTracker class is deprecated and replaced by using pvlib.pvsystem.PVSystem with the new pvlib.pvsystem.SingleAxisTrackerMount ( GH1176 )

Enhancements

Added read_pvgis_hourly() and get_pvgis_hourly() for reading and retrieving hourly solar radiation data and PV power output from PVGIS. ( GH1186 , GH849 )

Added map_variables option to get_pvgis_tmy() and read_pvgis_tmy() ( GH1250 , GH1268 )

Add get_bsrn() and read_bsrn() for retrieving and reading BSRN solar radiation data files. ( GH1254 , GH1145 , GH1015 )

Add get_cams() , parse_cams() , and read_cams() for retrieving, parsing, and reading CAMS Radiation and McClear time-series files. ( GH1175 )

In ModelChain , attributes which contain output of models are now collected into ModelChain.results . ( GH1076 , GH1067 )

Added Array class to represent an array of modules separately from a PVSystem . ( GH1076 , GH1067 )

Added FixedMount and SingleAxisTrackerMount classes to use with the new Array class ( GH1176 )

Added capability for modeling a PV system with multiple arrays in PVSystem . Updates the PVSystem API to operate on and return tuples where each element of the tuple corresponds to the input or output for a specific Array . ( GH1076 , GH1067 )

Support for systems with multiple Arrays added to ModelChain . This includes substantial API enhancements for accepting different weather input for each Array in the system. ( GH1076 , GH1067 )

Support for sandia_multi() and pvwatts_multi() added to PVSystem and ModelChain (as ac_model='sandia' and ac_model='pvwatts' ). ( GH1076 , GH1067 , GH1132 , GH1117 , GH1150 )

ModelChain ‘run_model’ methods now automatically switch to using 'effective_irradiance' (if available) for cell temperature models, when 'poa_global' is not provided in input weather or calculated from input weather data.

pvwatts_dc() now scales the DC power by pvsystem.PVSystem.modules_per_strings and pvsystem.PVSystem.strings_per_inverter . Note that both attributes still default to 1. ( GH1138 )

get_ac() is added to calculate AC power from DC power. Use parameter model to specify which inverter model to use. ( GH1147 , GH998 , GH1150 )

Added noct_sam() , a cell temperature model implemented in SAM. ( GH1177 , GH1195 )

Added pvsyst_temperature_coeff() to calculate the temperature coefficient of power for the pvsyst module model. ( GH1190 )

get_total_irradiance() and get_sky_diffuse() now fill in airmass if required and not provided. These functions now raise a ValueError if dni_extra is required and not provided. ( GH949 , GH1225 )

Bug fixes

Corrected an error in perez() where the horizon irradiance component was prevented from taking negative values. Negative values are intentional according to the original publication. Changes in output are expected to be small and primarily occur at low irradiance conditions. ( GH1238 , GH1239 )

Pass weather data to solar position calculations in prepare_inputs_from_poa() . ( GH1065 , GH1140 )

Reindl model fixed to generate sky_diffuse=0 when GHI=0. ( GH1153 , GH1154 )

Fix floating point round-off issue in aoi_projection() ( GH1185 , GH1191 )

Update GFS product names for GFS v16. ( GH1202 , GH1203 )

Take into account EgRef , dEgdT , irrad_ref and temp_ref when calling calcparams_cec() . ( GH1215 , GH1216 )

Corrected methodology error in wvm() . Tracks with fix in PVLib for MATLAB. ( GH1206 , GH1213 )

Corrected an error affecting detect_clearsky() when data time step is not one minute. Error was introduced in v0.8.1. ( GH1241 , GH1242 )

Corrected error affecting _compute_wavelet() when passing a pandas time series with a sampling rate faster than 1 second. ( GH1257 , GH1258 )

Changed deprecated use of .astype() to .view() in solarposition . ( GH1256 , GH1261 , GH1262 )

Fix singleaxis() AOI wrong when sun behind module. ( GH1273 , GH1221 )

Fix get_data() failure to correct for non-UTC timezones. ( GH1237 , GH1285 )

Fixed HRRR by changing model name to reflect change on the server. ( GH1291 , GH1292 )

Testing

Added init.py to pvlib/tests and subdirectories. This follows pytest recommendations for package layout and imports from conftest.py . Solves issue with test discovery in vscode. ( GH1204 )

Documentation

Update intro tutorial to highlight the use of historical meteorological data and to make the procedural and OO results match exactly. ( GH1116 , GH1144 )

Add a gallery example showing how to appropriately use interval-averaged weather data for modeling. ( GH1152 )

Update documentation links in pvlib.iotools.get_psm3() ( GH1169 )

Use Mount classes in introtutorial and pvsystem docs pages ( GH1267 )

Clarified how statistics are calculated for pvlib.clearsky.detect_clearsky() ( GH1070 , GH1243 )

Add gallery examples using the new Mount classes ( GH1266 )

Add “powered by pvlib” logos ( GH1277 )

Requirements

dataclasses is required for python 3.6 ( GH1076 )

h5py is now a required dependency. This replaces tables , which was formerly an optional dependency. ( GH1299 , GH1252 , GH1286 )

Contributors

Will Holmgren ( @wholmgren )

Cliff Hansen ( @cwhanse )

Will Vining ( @wfvining )

Anton Driesse ( @adriesse )

Mark Mikofski ( @mikofski )

Nate Croft ( @ncroft-b4 )

Kevin Anderson ( @kanderso-nrel )

Adam R. Jensen ( @AdamRJensen )

Joshua Stein ( @jsstein )

Tony Lorenzo ( @alorenzo175 )

Damjan Postolovski ( @dpostolovski )

Miguel Sánchez de León Peque ( @Peque )

Joe Ranalli ( @jranalli )

Chas Schweizer ( @cpr-chas )

Yoann Louvet ( @YoannUniKS )

Brandon Carpenter ( @hashstat )

@kahemker

@zhammond147

@PeterGrant

@rockstaedt

@MichaelHopwood

@EricDuminil

@FeiYao-Edinburgh

Deprecations

pvlib.irradiance.liujordan is deprecated. pvlib.irradiance.campbell_norman() replaces pvlib.irradiance.liujordan .

Enhancements

Add a numpy-based implementation of the SPECTRL2 spectral irradiance model pvlib.spectrum.spectrl2() ( GH1062 )

Create fuentes_celltemp() and add temperature_model='fuentes' option to ModelChain . ( GH1042 ) ( GH1073 )

Added pvlib.temperature.ross() for cell temperature modeling using only NOCT. ( GH1045 )

pvlib.clearsky.detect_clearsky() now uses centered rolling windows instead of left-aligned rolling windows. ( GH1074 )

The ‘times’ and ‘window_length’ parameters are now optional kwargs in pvlib.clearsky.detect_clearsky() . If omitted, ‘times’ is set equal to the index of parameter ‘measured’, and ‘window_length’ is set to 10 minutes. ( GH1074 )

Added pvlib.inverter.sandia_multi() and pvlib.inverter.pvwatts_multi() for modeling inverters with multiple MPPTs ( GH457 , GH1085 , GH1106 )

Added optional attributes parameter to pvlib.iotools.get_psm3() and added the option of fetching 5- and 15-minute PSM3 data. ( GH1086 )

Added pvlib.irradiance.campbell_norman() for estimating DNI, DHI and GHI from extraterrestrial irradiance. This function replaces pvlib.irradiance.liujordan ; users of pvlib.irradiance.liujordan should note that pvlib.irradiance.campbell_norman() expects different parameters. ( GH1104 )

pvlib.forecast.ForecastModel.cloud_cover_to_irradiance_campbell_norman() replaces pvlib.forecast.ForecastModel.cloud_cover_to_irradiance_liujordan . ( GH1104 )

Bug fixes

Fix issue with pvlib.temperature.fuentes() with timezone-aware inputs. ( GH1071 , GH1072 )

Raise ValueError from pvlib.modelchain.ModelChain.prepare_inputs() when input does not have a ‘dhi’ column. ( GH1092 , GH1093 )

Add missing modules (including shading and scaling ) to init.py . ( GH1103 )

Testing

Add airspeed velocity performance testing configuration and a few benchmarks. ( GH419 , GH1049 , GH1059 )

Add Python 3.9 CI configurations. ( GH1102 , GH1112 )

Update test_pvgis.py to be more flexible about the PVGIS copyright notice ( GH1121 )

Documentation

Update sphinx to 3.1.2 and use the recursive option in autosummary class template. ( GH1055 , GH1075 )

Add gallery example about backtracking on sloped terrain. ( GH1077 )

Add toggle button for code prompts to make copying code easier ( GH1096 )

Add project urls to setup.py for pypi page ( GH1119 )

Contributors

Kevin Anderson ( @kanderso-nrel )

Siyan (Veronica) Guo ( @veronicaguo )

Will Holmgren ( @wholmgren )

Cliff Hansen ( @cwhanse )

Will Vining ( @wfvining )

Michael Jurasovic ( @jurasofish )

Aziz Ben Othman ( @AzizCode92 )

Anton Driesse ( @adriesse )

Mark Mikofski ( @mikofski )

Junaid Fatehi ( @jhfatehi )

Breaking changes

The ivtools.py module has been reorganized into a subpackage and functions in ivtools.py have been renamed ( GH708 ):

Functions for fitting diode models are now in pvlib.ivtools.sdm

pvlib.ivtools.fit_sdm_cec_sam() is now pvlib.ivtools.sdm.fit_cec_sam()

pvlib.ivtools.fit_sdm_desoto() is now pvlib.ivtools.sdm.fit_desoto()

Functions for fitting the single diode equation are now in pvlib.ivtools.sde

pvlib.ivtools.fit_sde_sandia() is now pvlib.ivtools.sde.fit_sandia_simple()

Removed run_parallel_calculations and n_workers_for_parallel_calcs from pvlib.bifacial.pvfactors_timeseries() inputs ( GH902 ) ( GH934 )

pvlib.iotools.read_tmy3() can now only read local data files because the NREL RREDC server hosting the TMY3 dataset has been retired. For fetching TMY data from NREL servers, pvlib.iotools.get_psm3() is now recommended to retrieve newer PSM3 data over the older TMY3 data. ( GH996 ) ( GH1004 )

The tkinter-based file selection dialog has been removed from pvlib.iotools.read_tmy2() and pvlib.iotools.read_tmy3() ; the filepath is now a required parameter. ( GH1004 )

Removed systemdef function from pvsystem.py . This function was not used in pvlib and its output was not directly compatible with any pvlib function. See pvlib.iotools.read_tmy2() , pvlib.iotools.read_tmy3() , pvlib.location.Location.from_tmy() , and pvlib.pvsystem.LocalizedPVSystem for alternatives. ( GH965 ) ( GH1008 )

The following functions, methods, and arguments were deprecated in a previous release and have now been removed ( GH966 , GH1033 ):

pvsystem.PVSystem.ashraeiam . Use pvlib.pvsystem.PVSystem.get_iam() .

pvsystem.PVSystem.physicaliam . Use pvlib.pvsystem.PVSystem.get_iam() .

pvsystem.PVSystem.sapm_aoi_loss . Use pvlib.pvsystem.PVSystem.get_iam() .

pvsystem.ashraeiam . Use pvlib.iam.ashrae() .

pvsystem.physicaliam . Use pvlib.iam.physical() .

pvsystem.sapm_aoi_loss . Use pvlib.iam.sapm() .

pvsystem.sapm_celltemp . Use pvlib.temperature.sapm_cell() .

pvsystem.pvsyst_celltemp . Use pvlib.temperature.pvsyst_cell() .

times keyword argument of pvlib.modelchain.ModelChain.run_model() , pvlib.modelchain.ModelChain.complete_irradiance() , and pvlib.modelchain.ModelChain.prepare_inputs() . The index of the input DataFrame is used instead.

temp_model keyword argument of pvlib.modelchain.ModelChain() . Use temperature_model instead.

Deprecations

Moved functions related to inverters from pvsystem.py to inverter.py . Functions are renamed to follow a more consistent pattern, as follows ( GH886 ):

pvlib.pvsystem.snlinverter is now pvlib.inverter.sandia()

pvlib.pvsystem.pvwatts_ac is now pvlib.inverter.pvwatts()

pvlib.pvsystem.adrinverter is now pvlib.inverter.adr()

Argument ac_model for pvlib.modelchain.ModelChain now accepts 'sandia' , 'pvwatts' and 'adr' for the inverter models. ( GH886 )

pvlib.pvsystem.PVSystem module_type and racking_model now default to None . This continues a deprecation of assuming SAPM values for cell temperature modeling. In this v0.8 release series, calling pvlib.pvsystem.PVSystem.sapm_celltemp() without setting PVSystem.temperature_model_parameters , or a valid combination of PVsystem.module_type and PVsystem.racking_model , will cause PVSystem.temperature_model_parameters to be set to SAPM values for a glass/glass module in open racking and emit a warning. In v0.9, users must provide temperature_model_parameters or a valid combination of module_type and racking_model . ( GH1030 , GH1033 )

Deprecated arbitrary keyword arguments for pvlib.location.Location , pvlib.pvsystem.PVSystem , pvlib.tracking.SingleAxisTracker , and pvlib.modelchain.ModelChain . Supplying arbitrary keyword to these objects will result in TypeErrors in v0.9. ( GH1029 , GH1053 )

pvlib.pvsystem.LocalizedPVSystem and pvlib.pvsystem.LocalizedSingleAxisTracker are deprecated and will be removed in 0.9. Use pvlib.location.Location , pvlib.pvsystem.PVSystem , pvlib.tracking.SingleAxisTracker , and pvlib.modelchain.ModelChain instead. ( GH1029 , GH1034 , GH1053 )

Enhancements

Update pvfactors_timeseries() to run with pvfactors v1.4.1 ( GH902 )( GH934 )

Add pvlib.iam.marion_diffuse() and pvlib.iam.marion_integrate() to calculate IAM values for diffuse irradiance. ( GH984 )

Add pvlib.shading.sky_diffuse_passias() , pvlib.shading.masking_angle_passias() , and pvlib.shading.masking_angle() to model diffuse shading loss. ( GH1017 )

Add pvlib.inverter.fit_sandia() that fits the Sandia inverter model to a set of inverter efficiency curves. ( GH1011 )

Add pvlib.ivtools.sdm.fit_pvsyst_sandia() and pvlib.ivtools.sdm.fit_desoto_sandia() for fitting the Pvsyst and De Soto models to IV curve data ( GH227 )( GH708 )

Add factory methods with_pvwatts() with_sapm() to create ModelChain objects configured for the respective modeling paradigms. The configurations are defined in modelchain.PVWATTS_CONFIG , and modelchain.SAPM_CONFIG . ( GH1013 , GH1022 )

Added racking_model , module_type , and temperature_model_parameters to PVSystem and SingleAxisTracker repr methods. ( GH1027 )

Added calc_axis_tilt() to calculate the tracker axes tilt and calc_cross_axis_tilt() to calculate the cross-axis tilt, which is the angle, relative to horizontal, of the line formed by the intersection between the slope containing the tracker axes and a plane perpendicular to the tracker axes. ( GH823 )

Added cross_axis_tilt argument to singleaxis() and SingleAxisTracker() which defaults to zero. Use calc_cross_axis_tilt() to calculate the cross-axis tilt angle if necessary. ( GH823 )

Added ability for pvlib.soiling.hsu() to accept arbitrary time intervals. ( GH980 )

Added pvlib.temperature.fuentes() for cell temperature modeling. ( GH1037 )

Add pvlib.pvsystem.combine_loss_factors() as general purpose function to combine loss factors with a common index. Partialy addresses GH988 . Contributed by Brock Taute @btaute

Add capability to run a ModelChain starting with plane-of-array or effective irradiance, or with back-of-module or cell temperature data. New methods are pvlib.modelchain.ModelChain.run_model_from_poa() , pvlib.modelchain.ModelChain.run_model_from_effective_irradiance() , and pvlib.modelchain.ModelChain.prepare_inputs_from_poa() ( GH536 , GH943 )

Bug fixes

Fixed unit and default value errors in pvlib.soiling.hsu() . ( GH977 , GH980 )

Handle NUL characters and fix version column dtype in read_crn() . ( GH1025 )

Fix low sun angle tracker rotation calculation. ( GH824 )

Fix issue with big-endian and little-endian data in forecast.py . ( GH921 )

Testing

Decorator pvlib.conftest.fail_on_pvlib_version() can now be applied to functions that require args or kwargs. ( GH973 )

Test added for pvlib.modelchain.ModelChain to confirm ValueError when ac_model is an invalid string. ( GH886 )

Add minimum requirements configuration to Azure Pipelines build. ( GH1006 )

Update the data/test_psm3_tmy-2017.csv datafile to match the updated NSRDB data. ( GH1005 , GH1007 )

Add wrappers around the pandas assert_X_equal functions to accommodate the changed API and default precision thresholds in pandas 1.1.0 ( GH1018 , GH1021 )

Add github action for publishing tags to pypi.org . ( GH950 , GH1038 , GH1039 )

Remove Travis CI configuration. ( GH950 )

Documentation

Improved formatting and content of docstrings in pvlib.atmosphere . ( GH969 )

Fix LaTeX rendering in pvlib.singlediode.bishop88() . ( GH967 )

Clarify units for heat loss factors in pvlib.temperature.pvsyst_cell() and pvlib.temperature.faiman() . ( GH960 )

Added hsu soiling model example to the gallery. ( GH990 )

Add make.bat so that docs can be built on Windows without make installed. ( GH978 , GH981 )

Add instructions to build the documentation. ( GH982 )

Corrected key names for pvlib.inverter.sandia() . ( GH976 , GH886 )

Add a transposition gain example to the gallery. ( GH979 )

Add a gallery example of calculating diffuse IAM using pvlib.iam.marion_diffuse() . ( GH984 )

Add a gallery example of modeling diffuse shading loss. ( GH1017 )

Add minigalleries to API reference pages. ( GH991 )

Requirements

Python 3.6 or greater. ( GH1035 )

Minimum pandas version increased to v0.22.0, released Dec 31, 2017. ( GH1003 )

Scipy >= v1.2.0, released Dec 17, 2018, is now a required dependency rather an optional dependency. ( GH972 , GH1035 )

Contributors

Cliff Hansen ( @cwhanse )

Kevin Anderson ( @kanderso-nrel )

Mark Mikofski ( @mikofski )

Joshua S. Stein ( @jsstein )

Marc A. Anoma ( @anomam )

Will Holmgren ( @wholmgren )

Brock Taute ( @btaute )

Cameron Stark ( @CameronTStark )

@kahemker

Miguel Sánchez de León Peque ( @Peque )

Stephen Lightfoote ( @srlightfoote )

API Changes

pvlib.forecast.ForecastModel now requires start and end arguments to be tz-localized. ( GH877 , GH879 )

pvlib.iotools.read_tmy3() when coerced to a single year now returns indices that are monotonically increasing. Therefore, the last index will be January 1, 00:00 of the next year. ( GH910 )

Renamed pvlib.losses to pvlib.soiling . Additional loss models will go into code modules named for the loss or effect type. ( GH935 , GH891 )

Renamed pvlib.losses.soiling_hsu to pvlib.soiling.hsu() ( GH935 )

Enhancements

TMY3 dataframe returned by read_tmy3() now contains the original Date (MM/DD/YYYY) and Time (HH:MM) columns that the indices were parsed from. ( GH866 )

Add pvlib.pvsystem.PVSystem.faiman() and added temperature_model='faiman' option to ModelChain ( GH897 ) ( GH836 ).

Add Kimber soiling model pvlib.losses.soiling_kimber() . ( GH860 )

Add pvlib.iotools.read_pvgis_tmy() for files downloaded using the

• Add Kimber soiling model pvlib.soiling.kimber() . ( GH860 , :issue935)

Add read_pvgis_tmy() for files downloaded using the PVGIS tool. ( GH880 )

Add pvlib.temperature.sapm_cell_from_module() to convert back of module temperature to cell temperature ( GH927 )

Add new module pvlib.snow to contain models related to snow coverage and effects on a PV system. ( GH764 )

Add snow coverage model pvlib.snow.coverage_nrel() and function to identify when modules are fully covered by snow pvlib.snow.fully_covered_nrel() . ( GH577 )

Add function pvlib.snow.dc_loss_nrel() for effect of snow coverage on DC output. ( GH764 )

Add capability to calculate current at reverse bias using an avalanche breakdown model, affects pvlib.singlediode.bishop88() , pvlib.singlediode.bishop88_i_from_v() , pvlib.singlediode.bishop88_v_from_i() , pvlib.singlediode.bishop88_mpp() . ( GH948 )

Add weather data arguments in get_solarpostion method of modelchain.ModelChain.prepare_inputs modelchain.ModelChain.prepare_inputs() ( GH936 )

Bug fixes

Fix read_tmy3() parsing when February contains a leap year. ( GH866 )

Implement NREL Developer Network API key for consistent success with API calls in pvlib.tests.iotools.test_psm3 . ( GH873 )

Fix issue with pvlib.location.Location creation when passing tz=datetime.timezone.utc . ( GH879 )

Fix documentation homepage title to “pvlib python” based on first heading on the page. ( GH890 ) ( GH888 )

Fix missing 0.7.0 what’s new entries about changes to PVSystem.pvwatts_ac . Delete unreleased 0.6.4 what’s new file. ( GH898 )

Compatibility with cftime 1.1. ( GH895 )

Minor implemention changes to avoid runtime and deprecation warnings in detect_clearsky() , martin_ruiz_diffuse() , soiling_hsu() , and various test functions.

Fix read_tmy3() so that when coerced to a single year the TMY3 index will be monotonically increasing. ( GH910 )

Fix pvlib.spa.julian_day_dt() so that microseconds are scaled correctly ( GH940 ) ( GH942 )

Testing

Rename system fixture to sapm_dc_snl_ac_system in model chain tests. ( GH908 , GH915 ).

Implement pytest-remotedata to increase test suite speed. Requires --remote-data pytest flag to execute data retrieval tests over a network. ( GH882 )( GH896 )

Add Python3.8 to Azure Pipelines CI. ( GH903 )( GH904 )

Add documentation build test to Azure Pipelines CI. ( GH909 )

Implement the pytest.mark.flaky decorator from pytest-rurunfailures pytest-dev/pytest-rerunfailures on all network dependent iotools tests to repeat them on failure. ( GH919 )

Separate azure-pipelines.yml platform-specific tests to their own templates located in ./ci/azure/ . ( GH926 )

Documentation

Add NumFOCUS affiliation to Sphinx documentation. ( GH862 )

Add example of IV curve generation. ( GH872 )

Add section about gallery examples to Contributing guide. ( GH905 )

Add section with link to Code of Conduct in Contributing guide. ( GH922 )

Add example of GHI to POA transposition ( GH933 )

Requirements

nrel-pysam (optional) minimum set to v1.0.0 ( GH874 )

cftime (optional) minimum set to >=1.1.1. Use of only_use_python_datetimes kwarg in netCDF4.num2date in forecast.py requires >=1.1.1 which is >=Python3.6. ( GH947 )

Contributors

Mark Mikofski ( @mikofski )

Cliff Hansen ( @cwhanse )

Cameron T. Stark ( @camerontstark )

Will Holmgren ( @wholmgren )

Kevin Anderson ( @kanderso-nrel )

Karthikeyan Singaravelan ( @tirkarthi )

Siyan (Veronica) Guo ( @veronicaguo )

Eric Fitch ( @ericf900 )

Joseph Palakapilly ( @JPalakapilly )

Auguste Colle( @augustecolle )

Ahan M R ( @Ahanmr )

This is a major release that drops support for Python 2 and Python 3.4. We recommend all users of v0.6.3 upgrade to this release after checking API compatibility notes.

Python 2.7 support ended on June 1, 2019. ( GH501 ) Minimum numpy version is now 1.12.0. Minimum pandas version is now 0.18.1. ( GH830 , GH748 )

API Breaking Changes

The effective_irradiance argument for pvsystem.sapm() now requires units of W/m^2. Previously, units for this input were suns. A RuntimeWarning warning is raised if all effective_irradiance < 2.0 .

The output of pvsystem.sapm_effective_irradiance() is now in units of W/m2 rather than suns.

Calling pvlib.pvsystem.retrieve_sam() with no parameters will raise an exception instead of displaying a dialog.

The modelchain.ModelChain.diode_params attribute is now formatted in a pandas.DataFrame with DatetimeIndex , rather than in a tuple.

PVSystem.pvwatts_ac now uses inverter DC input limit PVSystem.inverter_parameters['pdc0'] instead of module nameplate capacity PVSystem.module_parameters['pdc0'] . ( GH734 )

ModelChain.infer_ac_model now uses the presence of the key 'pdc0' PVSystem.inverter_parameters to determine if the pvwatts_ac inverter model should be used. The inference method previously looked for the key in PVSystem.module_parameters . ( GH734 )

API Changes with Deprecations

• Changes related to cell temperature models ( GH678 ):
• Changes to functions

Moved functions for cell temperature from pvsystem.py to temperature.py .

Renamed pvsystem.sapm_celltemp and pvsystem.pvsyst_celltemp to temperature.sapm_cell and temperature.pvsyst_cell .

temperature.sapm_cell returns only the cell temperature, whereas the old pvsystem.sapm_celltemp returned a DataFrame with both cell and module temperatures.

Created temperature.sapm_module to return module temperature using the SAPM temperature model.

Changed the order of arguments for pvsystem.sapm_celltemp , pvsystem.pvsyst_celltemp and PVSystem.sapm_celltemp to be consistent among cell temperature model functions.

Removed model as a kwarg from temperature.sapm_cell and temperature.pvsyst_cell . These functions now require model-specific parameters.

Added the argument irrad_ref , default value 1000, to temperature.sapm_cell .

• Changes to named temperature model parameter sets

Renamed pvsystem.TEMP_MODEL_PARAMS to temperature.TEMPERATURE_MODEL_PARAMETERS .

temperature.TEMPERATURE_MODEL_PARAMETERS uses dict rather than tuple for a parameter set.

Names for parameter sets in temperature.TEMPERATURE_MODEL_PARAMETERS have changed.

Parameter sets for the SAPM cell temperature model named ‘open_rack_polymer_thinfilm_steel’ and ‘22x_concentrator_tracker’ are considered obsolete and have been removed.

• Changes to PVSystem class

Changed the model kwarg in PVSystem.sapm_celltemp and PVSystem.pvsyst_celltemp to parameter_set . parameter_set expects a str which is a valid key for temperature.TEMPERATURE_MODEL_PARAMETERS for the corresponding temperature model.

Added an attribute PVSystem.module_type (str) to record module front and back materials, default is glass_polymer .

Changed meaning of PVSystem.racking_model to describe racking only, e.g., default is open_rack .

Added an attribute PVSystem.temperature_model_parameters (dict). to contain temperature model parameters.

If PVSystem.temperature_model_parameters is not specified and PVSystem.racking_model and PVSystem.module_type combine to a valid parameter set name for the SAPM cell temperature model, that parameter set is assigned to PVSystem.temperature_model_parameters . Otherwise PVSystem.temperature_model_parameters is assigned an empty dict. The result is that the default parameter set for SAPM cell temperature model is open_rack_glass_polymer ; the old default was open_rack_glass_glass .

• Changes to ModelChain class

ModelChain.temp_model renamed to ModelChain.temperature_model .

ModelChain.temperature_model now defaults to None . The temperature model can be inferred from PVSystem.temperature_model_parameters .

ModelChain.temperature_model_parameters now defaults to None . The temperature model can be inferred from PVSystem.temperature_model_parameters .

ModelChain.temps attribute renamed to ModelChain.cell_temperature , and its datatype is now numeric rather than DataFrame .

If PVSystem.temperature_model_parameters is not specified, ModelChain defaults to old behavior, using the SAPM temperature model with parameter set open_rack_glass_glass . This behavior is deprecated, and will be removed in v0.8. In v0.8 PVSystem.temperature_model_parameters will be required for ModelChain .

Implemented pvsyst as an option for ModelChain.temperature_model .

modelchain.basic_chain has a new required argument temperature_model_parameters .

• Changes related to IAM (AOI loss) functions ( GH680 ):
• Changes to functions

Moved functions from pvsystem.py to iam.py . pvsystem IAM functions are deprecated and will be removed in v0.8.

• Functions are renamed to a consistent pattern:

pvsystem.physicaliam is iam.physical

pvsystem.ashraeiam is iam.ashrae

pvsystem.sapm_aoi_loss is iam.sapm

• Changes to PVSystem class

IAM models are provided by PVSystem.get_iam with kwarg iam_model .

Methods PVSystem.ashraeiam , PVSystem.physicaliam and PVSystem.sapm_aoi_loss are deprecated and will be removed in v0.8.

• Changes related to spectral modifier ( GH782 ):
• Changes to functions

Added the argument pw_min and pw_max , default values 0.1 and 8 resp., to pvlib.atmosphere.first_solar_spectral_correction() . This function now returns NaN if pw value higher than pw_max .

The times keyword argument has been deprecated in the pvlib.modelchain.ModelChain.run_model() , pvlib.modelchain.ModelChain.prepare_inputs() , and pvlib.modelchain.ModelChain.complete_irradiance() methods. Model times are now determined by the input weather . DataFrame . Therefore, the weather DataFrame must have a DatetimeIndex . The weather argument of the above methods is now the first, required positional argument and the times argument is kept as the second keyword argument for capability during the deprecation period.

Parameter pvsystem.DC_MODEL_PARAMS is renamed to pvsystem._DC_MODEL_PARAMS . Users should not rely on this dictionary’s existence or structure.

Other API Changes

pvlib.iotools.midc.read_midc() now passes additional keyword arguments to pandas.read_csv

Add timeout argument to pvlib.iotools.midc.read_midc_raw_data_from_nrel()

pvlib.bifacial is now imported when pvlib is imported. ( GH766 )

Enhancements

Created one new temperature model function: pvlib.temperature.faiman() . ( GH750 )

Created two new incidence angle modifier (IAM) functions: pvlib.iam.martin_ruiz() and pvlib.iam.interp() . ( GH751 )

Created one new incidence angle modifier (IAM) function for diffuse irradiance: pvlib.iam.martin_ruiz_diffuse() . ( GH751 )

Add the martin_ruiz IAM function as an option for ModelChain.aoi_model .

Updated the file for module parameters for the CEC model, from the SAM file dated 2017-6-5 to the SAM file dated 2019-03-05. ( GH761 )

Updated the file for inverter parameters for the CEC model, from the SAM file dated 2018-3-18 to the SAM file dated 2019-03-05. ( GH761 )

Added recombination current parameters to bishop88 single-diode functions and also to pvlib.pvsystem.max_power_point() . ( GH762 )

Add ivtools module to contain functions for IV model fitting.

Add fit_sde_sandia() , a simple method to fit the single diode equation to an IV curve.

Add fit_sdm_cec_sam() , a wrapper for the CEC single diode model fitting function ‘6parsolve’ from NREL’s System Advisor Model.

Add fit_sdm_desoto() , a method to fit the De Soto single diode model to the typical specifications given in manufacturers datasheets.

Add timeout to pvlib.iotools.get_psm3() .

Add wvm() , a port of the wavelet variability model for computing reductions in variability due to a spatially distributed plant.

Add from_epw() , a method to create a Location object from epw metadata, typically coming from pvlib.iotools.epw.read_epw .

Bug fixes

Fix handling of keyword arguments in forecasts.get_processed_data . ( GH745 )

Fix output as Series feature in pvlib.pvsystem.ashraeiam() .

Fix rounding issue in clearsky._linearly_scale , a function that converts longitude or latitude degree to an index number in a Linke turbidity lookup table. Also rename the function to clearsky._degrees_to_index . ( GH754 )

Fix reading raw MIDC CSV files from NREL where the number of header columns does not match the number of data columns.

Fix installation issue due to missing requests dependency. ( GH725 )

PVSystem.pvwatts_ac now uses inverter DC input limit PVSystem.inverter_parameters['pdc0'] instead of module nameplate capacity PVSystem.module_parameters['pdc0'] . ( GH734 )

Testing

Added 30 minutes to timestamps in test_psm3.csv to match change in NSRDB ( GH733 )

Added tests for methods in bifacial.py.

Added tests for changes to cell temperature models.

Add tests configuration for bare python environment (no conda). ( GH727 )

Added tests for changes to IAM models.

Added test for ModelChain.infer_aoi_model .

Documentation

Corrected docstring for pvsystem.PVSystem.sapm

Fixed broken ipython examples from CEC data updates

Edited docstring for pvsystem.sapm to remove DataFrame option for input module . The DataFrame option was never tested and would cause an error if used. ( GH785 )

Note warning about _TMY3.epw files retrieved from energyplus.net in docstring of epw.read_epw

Improved sphinx rendering of API reference entries for clearsky.ineichen , clearsky.haurwitz , tracking.singleaxis , iotools.read_midc , Location.from_tmy , ModelChain.run_model , ModelChain.complete_irradiance , and ModelChain.prepare_inputs

Removed duplicate pvwatts_losses entry in api.rst

Removal of prior version deprecations

Removed irradiance.extraradiation .

Removed irradiance.grounddiffuse .

Removed irradiance.total_irrad .

Removed irradiance.globalinplane .

Removed atmosphere.relativeairmass .

Removed atmosphere.relativeairmass .

Removed solarposition.get_sun_rise_set_transit .

Removed tmy module.

Removed ModelChain.singlediode method.

Removed ModelChain.prepare_inputs clearsky assumption when no irradiance data was provided.

Requirements

numpy minimum increased to v1.12.0, released in 2017. ( GH830 )

pandas minimum increased to v1.18.1, released in 2016. ( GH748 )

Contributors

Mark Campanellli ( @markcampanelli )

Will Holmgren ( @wholmgren )

Cliff Hansen ( @cwhanse )

Oscar Dowson ( @odow )

Anton Driesse ( @adriesse )

Alexander Morgan ( @alexandermorgan )

Miguel Sánchez de León Peque ( @Peque )

Tanguy Lunel ( @tylunel )

Veronica Guo ( @veronicaguo )

Joseph Ranalli ( @jranalli )

Tony Lorenzo ( @alorenzo175 )

Todd Karin ( @toddkarin )

Mark Mikofski ( @mikofski )

Kevin Anderson ( @kevinsa5 )

Cameron Stark ( @camerontstark )

Janine Freeman ( @janinefreeman )

Roel Loonen ( @roelloonen )

Birgit Schachler ( @birgits )

Hamilton Kibbe ( @hamiltonkibbe )

Adam Peretti ( @aperetti )

Cedric Leroy ( @cedricleroy )

Joseph Palakapilly ( @JPalakapillyKWH )

( @shall-resurety )

This is a minor release on top of v0.6.2 to fix an installation issue. We recommend that all users of v0.6.1 and v0.6.2 upgrade to this release.

Python 2.7 support will end on June 1, 2019 . Releases made after this date will require Python 3. This release is likely to be the last that supports Python 2.7. ( GH501 )

Bug fixes

Fix installation issue due to missing requests dependency. ( GH725 )

Contributors

Will Holmgren ( @wholmgren )

This is a minor release. We recommend all users of v0.6.1 upgrade to this release.

Python 2.7 support will end on June 1, 2019 . Releases made after this date will require Python 3. This release is likely to be the last that supports Python 2.7. ( GH501 )

Minimum pandas requirement bumped 0.15.0=>0.16.0

API Changes

erbs() doy argument changed to datetime_or_doy to be consistent with allowed types and similar functions ( disc() , get_extra_radiation() ). ( GH681 )

erbs() DataFrame vs. OrderedDict return behavior now determined by type of datetime_or_doy instead of ghi or zenith . ( GH681 )

Added min_cos_zenith and max_zenith keyword arguments to erbs() . ( GH681 )

Deprecated prepare_inputs() assumption of clear sky if no irradiance fields were provided. ( GH705 , GH707 )

Remove automatic column name mapping from read_midc() and read_midc_raw_data_from_nrel() and added optional keyword argument variable_map to map columns. ( GH721 )

Update pvfactors_timeseries() and tests to use pvfactors v1.0.1 ( GH699 )

Enhancements

Add US CRN data reader to IO Tools . ( GH666 )

Add SOLRAD data reader to IO Tools . ( GH667 )

Add EPW data reader to IO Tools . ( GH591 )

Add PSM3 reader to IO Tools . ( GH592 )

Improve ModelChain inference method error text. ( GH621 )

Bug fixes

Compatibility with pandas 0.24 deprecations. ( GH659 )

pvwatts_ac() raised ZeroDivisionError when called with scalar pdc=0 and a RuntimeWarning for array(0) input. Now correctly returns 0s of the appropriate type. ( GH675 )

Fixed erbs() behavior when zenith is near 90 degrees. ( GH681 )

dni() now referenced in API under Decomposing and Combining irradiance header. ( GH686 )

Fixed NaN output from singleaxis() when sun near horizon. ( GH656 )

Fixed numpy warnings in singleaxis() when comparing NaN values to limits. ( GH622 )

Change ModelChain to apply pvwatts_losses to mc.dc instead of mc.ac . ( GH696 )

Fixed a bug in the day angle equation for the ASCE extraterrestrial irradiance model. ( GH211 )

Silenced divide by 0 irradiance warnings in klucher() and calcparams_desoto() . ( GH698 )

Fix NDFD model by updating variables.

Fix format_index() to parse non one-minute data correctly. ( GH709 )

Testing

Remove most expected warnings emitted by test suite. ( GH698 )

Contributors

Cliff Hansen ( @cwhanse )

Will Holmgren ( @wholmgren )

Roel Loonen ( @roelloonen )

Todd Hendricks ( @tahentx )

Kevin Anderson ( @kevinsa5 )

@bentomlinson

@yxh289

Jonathan Gaffiot ( @jgaffiot )

Leland Boeman ( @lboeman )

Marc Anoma ( @anomam )

This is a minor release. We recommend all users of v0.6.0 upgrade to this release.

Python 2.7 support will end on June 1, 2019 . Releases made after this date will require Python 3. ( GH501 )

Minimum pandas requirement bumped 0.14.0=>0.15.0

API Changes

Created the pvlib.iotools subpackage. ( GH29 , GH261 )

Deprecated tmy , tmy.readtmy2 and tmy.readtmy3 ; they will be removed in v0.7. Use the new pvlib.iotools.read_tmy2() and pvlib.iotools.read_tmy3() instead. ( GH261 )

Added keyword argument horizon to pyephem() and calc_time() with default value '+0:00' . ( GH588 )

Add max_airmass keyword argument to pvlib.irradiance.disc() . Default value ( max_airmass=12 ) is consistent with polynomial fit in original paper describing the model. This change may result in different output of functions that use the disc Kn calculation for times when input zenith angles approach 90 degrees. This includes pvlib.irradiance.dirint() and pvlib.irradiance.dirindex() when min_cos_zenith and max_zenith kwargs are used, as well as pvlib.irradiance.gti_dirint() . ( GH450 )

Changed key names for components returned from pvlib.clearsky.detect_clearsky() . ( GH596 )

Changed function name from pvlib.solarposition.get_rise_set_transit (deprecated) to pvlib.solarposition.sun_rise_set_transit_spa. `sun_rise_set_transit_spa() requires time input to be localized to the specified latitude/longitude. ( GH316 )

Created new bifacial section for pvfactors limited implementation ( GH421 )

Enhancements

Add sun_rise_set_transit_ephemto calculate sunrise, sunset and transit times using pyephem (:issue:114() )

Add geometric functions for sunrise, sunset, and sun transit times, sun_rise_set_transit_geometric() ( GH114 )

Add Location class method get_sun_rise_set_transit()

Created pvlib.iotools.read_srml() and pvlib.iotools.read_srml_month_from_solardat to read University of Oregon Solar Radiation Monitoring Laboratory data. ( GH589 )

Created pvlib.iotools.read_surfrad() to read NOAA SURFRAD data. ( GH590 )

Created pvlib.iotools.read_midc() and pvlib.iotools.read_midc_raw_data_from_nrel() to read NREL MIDC data. ( GH601 )

Created pvlib.iotools.get_ecmwf_macc() and pvlib.iotools.read_ecmwf_macc() to get and read ECMWF MACC data. ( GH602 )

Use HRRR modeled surface temperature values instead of inferring from isobaric values and modeled wind speed instead of inferring from gust. ( GH604 )

Change pvlib.pvsystem.sapm_spectral_loss() to avoid numpy warning.

Add warning message when pvlib.spa() is reloaded. ( GH401 )

Add option for pvlib.irradiance.disc() to use relative airmass by supplying pressure=None . ( GH449 )

Created pvlib.pvsystem.pvsyst_celltemp() to implement PVsyst’s cell temperature model. ( GH552 )

Created pvlib.bifacial.pvfactors_timeseries() to use open-source pvfactors package to calculate back surface irradiance ( GH421 )

Add PVSystem class method pvsyst_celltemp() ( GH633 )

Add pvlib.irradiance.clearsky_index() to calculate clear-sky index from measured GHI and modeled clear-sky GHI. ( GH551 )

Bug fixes

Fix when building documentation using Matplotlib 3.0 or greater.

~pvlib.spa.calculate_deltat : Fix constant coefficient of the polynomial expression for years >= 1860 and < 1900, fix year 2050 which was returning 0. ( GH600 )

Fix and improve hour_angle() ( GH598 )

Fix error in pvlib.clearsky.detect_clearsky() ( GH506 )

Fix documentation errors when using IPython >= 7.0.

Fix error in pvlib.modelchain.ModelChain.infer_spectral_model() ( GH619 )

Fix error in pvlib.spa when using Python 3.7 on some platforms.

Fix error in pvlib.irradiance._delta_kt_prime_dirint() ( GH637 ). The error affects the first and last values of DNI calculated by the function pvlib.irradiance.dirint()

Fix errors on Python 2.7 and Numpy 1.6. ( GH642 )

Replace deprecated np.asscalar with array.item() . ( GH642 )

Testing

Add test for hour_angle() ( GH597 )

Update tests to be compatible with pytest 4.0. ( GH623 )

Add tests for pvlib.bifacial.pvfactors_timeseries() implementation ( GH421 )

Contributors

Will Holmgren ( @wholmgren )

Leland Boeman ( @lboeman )

Cedric Leroy ( @cedricleroy )

Ben Ellis ( @bhellis725 )

Cliff Hansen ( @cwhanse )

Mark Mikofski ( @mikofski )

Anton Driesse ( @adriesse )

Cameron Stark ( @camerontstark )

Jonathan Gaffiot ( @jgaffiot )

Marc Anoma ( @anomam )

Anton Driesse ( @adriesse )

Kevin Anderson ( @kevinsa5 )

This is a major release and contains a large number of API changes, new features, and bug fixes. Users should carefully read the changelog below before upgrading.

Python 2.7 support will end on June 1, 2019 . Releases made after this date will require Python 3. ( GH501 )

API Changes

pvlib python is changing a handful of function names. In general, functions that can calculate a quantity using multiple algorithms now start with the prefix get_ . For example, relativeairmass can calculate airmass using one of many model arguments. Its name has been changed to get_relative_airmass() . The old function names remain in this release, but will emit a PVLibDeprecationWarning when called. The old functions will be removed in the v0.7 release. Functions composed of multiple words jammed together have been renamed with underscores separating the words (see above). Each change is detailed below. ( GH427 )

Deprecated relativeairmass ; it will be removed in v0.7. Use the new get_relative_airmass() instead. ( GH427 )

Deprecated absoluteairmass ; it will be removed in v0.7. Use the new get_absolute_airmass() instead. ( GH427 )

Deprecated irradiance.globalinplane ; it will be removed in v0.7. Use the new poa_components() instead. ( GH427 )

Added poa_components() . Function is the same as the now-deprecated irradiance.globalinplane , but adds 'poa_sky_diffuse' and 'poa_ground_diffuse' to the output. ( GH427 )

Deprecated irradiance.extraradiation ; it will be removed in v0.7. Use pvlib.irradiance.get_extra_radiation() instead. ( GH427 )

Deprecated irradiance.grounddiffuse ; it will be removed in v0.7. Use get_ground_diffuse() instead. ( GH427 )

Added get_poa_sky_diffuse() . ( GH427 )

Deprecated irradiance.total_irrad ; it will be removed in v0.7. Use get_total_poa_irradiance() instead. ( GH427 )

Removed 'klutcher' from get_sky_diffuse / total_irrad . This misspelling was deprecated long ago but never removed. ( GH97 )

calcparams_desoto() now requires arguments for each module model parameter. ( GH462 )

Add losses_parameters attribute to PVSystem objects and remove the kwargs support from PVSystem.pvwatts_losses. Enables custom losses specification in ModelChain calculations. ( GH484 )

removed irradiance parameter from ModelChain.run_model and ModelChain.prepare_inputs

Add perez_enhancement keyword argument to clearsky.ineichen to control whether or not the “perez enhancement factor” is applied. The enhancement factor was always applied until now. Now it is turned off by default. The enhancement factor can yield unphysical results, especially for latitudes closer to the poles and especially in the winter months. It may yield improved results under other conditions. ( GH435 )

Add min_cos_zenith, max_zenith keyword arguments to disc, dirint, and dirindex functions. ( GH311 , GH396 )

Method ModelChain.infer_dc_model now returns a tuple (function handle, model name string) instead of only the function handle ( GH417 )

Add DC model methods desoto and pvsyst to ModelChain, and deprecates DC model method singlediode (singlediode defaults to desoto until v0.7.0) ( GH487 )

Add the CEC module model in pvsystem.calcparams_cec and ModelChain.cec. The CEC model differs from the desoto model by using the parameter Adjust. Modules selected from the SAM CEC library sam-library-cec-modules-2017-6-5.csv include the Adjust parameter and ModelChain.infer_dc_model will now select the cec model rather than the desoto model. ( GH463 )

The behavior of irradiance.perez(return_components=True) has changed. The function previously returned a tuple of total sky diffuse and an OrderedDict/DataFrame of components. The function now returns an OrderedDict/DataFrame with total sky diffuse and each component. The behavior for return_components=False remains unchanged. ( GH434 )

Enhancements

Add sea surface albedo in irradiance.py ( GH458 )

Implement first_solar_spectral_loss() in modelchain.py ( GH359 )

Clarify arguments Egref and dEgdT for calcparams_desoto() ( GH462 )

Add pvsystem.calcparams_pvsyst to compute values for the single diode equation using the PVsyst v6 model ( GH470 )

Extend singlediode() with an additional keyword argument method in ('lambertw', 'newton', 'brentq') , default is 'lambertw' , to select a method to solve the single diode equation for points on the IV curve. Selecting either 'brentq' or 'newton' as the method uses bishop88() with the corresponding method. ( GH410 )

Implement new methods 'brentq' and 'newton' for solving the single diode equation for points on the IV curve. 'brentq' uses a bisection method (Brent, 1973) that may be slow but guarantees a solution. 'newton' uses the Newton-Raphson method and may be faster but is not guaranteed to converge. However, 'newton' should be safe for well-behaved IV curves. ( GH408 )

Implement bishop88() for explicit calculation of arbitrary IV curve points using diode voltage instead of cell voltage. If method is either 'newton' or 'brentq' and ivcurve_pnts in singlediode() is provided, the IV curve points will be log spaced instead of linear.

Implement estimate_voc() to estimate open circuit voltage by assuming (R_{sh} \to \infty) and (R_s=0) as an upper bound in bisection method for singlediode() when method is either 'newton' or 'brentq' .

Add max_power_point() method to compute the max power point using the new 'brentq' method.

Add new module pvlib.singlediode with low-level functions for solving the single diode equation such as: bishop88() , estimate_voc() , bishop88_i_from_v() , bishop88_v_from_i() , and bishop88_mpp() .

Add PVSyst thin-film recombination losses for CdTe and a:Si ( GH163 )

Python 3.7 officially supported. ( GH496 )

Improve performance of solarposition.ephemeris. ( GH512 )

Improve performance of Location.get_airmass. Most noticeable when solar position is supplied, time index length is less than 10000, and method is looped over. ( GH502 )

Add irradiance.gti_dirint function. ( GH396 )

Add irradiance.clearness_index function. ( GH396 )

Add irradiance.clearness_index_zenith_independent function. ( GH396 )

Add checking for consistency between module_parameters and dc_model. ( GH417 )

Add DC model methods 'desoto' and 'pvsyst' to ModelChain ( GH487 )

Add the CEC module model in pvsystem.calcparams_cec and ModelChain.cec . ( GH463 )

Add DC model methods desoto and pvsyst to ModelChain ( GH487 )

pvlib now ships with a pvlib[optional] installation option to automatically install packages needed to support additional pvlib features: pip install pvlib[optional] . Additional installation options include doc (requirements for minimal documentation build), test (requirements for testing), and all (optional + doc + test). ( GH553 , GH483 )

Set default alpha to 1.14 in angstrom_aod_at_lambda() ( GH563 )

tracking.singleaxis now accepts scalar and 1D-array input.

Bug fixes

Unset executable bits of irradiance.py and test_irradiance.py ( GH460 )

Fix failing tests due to column order on Python 3.6+ and Pandas 0.23+ ( GH464 )

ModelChain.prepare_inputs failed to pass solar_position and airmass to Location.get_clearsky. Fixed. ( GH481 )

Add User-Agent specification to TMY3 remote requests to avoid rejection. ( GH493 )

Fix pvlib.irradiance.klucher output is different for Pandas Series vs. floats and NumPy arrays. ( GH508 )

Make GitHub recognize the license, add AUTHORS.md, clarify shared copyright. ( GH503 )

Fix issue with non-zero direct irradiance contribution to Reindl, Klucher, and Hay-Davies diffuse sky algorithms when the sun is behind the array. ( GH526 )

Fix issue with dividing by near-0 cos(solar_zenith) values in Reindl and Hay-Davies diffuse sky algorithms. ( GH432 )

Fix argument order of longitude and latitude when querying weather forecasts by lonlat bounding box ( GH521 )

Fix issue with unbounded clearness index calculation in disc. ( GH540 )

Limit pvwatts_ac results to be greater than or equal to 0. ( GH541 )

Fix bug in get_relative_airmass(model=’youngirvine1967’). ( GH545 )

Fix bug in variable names returned by forecast.py’s HRRR_ESRL model. ( GH557 )

Fixed bug in tracking.singleaxis that mistakenly assigned nan values when the Sun was still above the horizon. No effect on systems with axis_tilt=0. ( GH569 )

Source distribution did not contain LICENSE file. Added LICENSE, AUTHORS.md, and some docs to MANIFEST. ( GH579 )

Patch SPA C-files to fix timezone macro name clash with pyconfig.h . ( GH168 )

Documentation

Expand testing section with guidelines for functions, PVSystem/Location objects, and ModelChain.

Updated several incorrect statements in ModelChain documentation regarding implementation status and default values. ( GH480 )

Expanded general contributing and pull request guidelines.

Added section on single diode equation with some detail on solutions used in pvlib-python ( GH518 )

Minor improvements and updates to installation documentation. ( GH531 )

Improve LocalizedPVSystem and LocalizedSingleAxisTracker documentation. ( GH532 )

Move the “Getting Started”/”Modeling Paradigms” section to a new top-level “Intro Examples” page.

Copy pvlib documentation’s “Getting support” section to README.md.

Add PVSystem documentation page. ( GH514 , GH319 )

Add example of Kasten Linke Turbidity calculation, discuss broadband AOD and Angstrom Turbidity Model. ( GH302 )

Add JOSS paper to “Citing pvlib-python” section.

Testing

Add pytest-mock dependency

Use pytest-mock to ensure that PVSystem and ModelChain methods call corresponding functions correctly. Removes implicit dependence on precise return values of some function/methods. ( GH394 )

Additional test refactoring to limit test result dependence to a single function per test. ( GH394 )

Use pytest-mock to ensure that ModelChain DC model is set up correctly.

Add Python 3.7 to build matrix

Make test_forecast.py more robust. ( GH293 )

Improve test_atmosphere.py. ( GH158 )

Add LGTM.com integration. ( GH554 )

Add SticklerCI integration.

Add codecov integration.

Contributors

Will Holmgren ( @wholmgren )

Yu Cao ( @tsaoyu )

Cliff Hansen ( @cwhanse )

Mark Mikofski ( @mikofski )

Alan Mathew ( @alamathe1 )

Xavier Rene-Corail ( @xcorail )

Anton Driesse ( @adriesse )

Mark Campanelli ( @thunderfish24 )

Cedric Leroy ( @cedricleroy )

Jessica Forbess ( @jforbess )

Jeff Newmiller ( @jdnewmil )

@josricha

Marc A. Anoma ( @anomam )

William C Grisaitis ( @grisaitis )

Karel De Brabandere ( @kdebrab )

@tadatoshi

API Changes

removed unused ‘pressure’ arg from irradiance.liujordan function ( GH386 )

replaced logging.warning calls with warnings.warn calls, and removed logging.debug calls. We encourage users to explore tools such as pdb and trackback in place of the logging.debug calls. Fixes ( GH447 ).

Enhancements

Improve clearsky.lookup_linke_turbidity speed, changing .mat source file to .h5 ( GH437 )

Updated libraries for CEC module parameters to SAM release 2017.9.5 (library dated 2017.6.30) and CEC inverter parameters to file posted to www.github.com/NREL/SAM on 2018.3.18, with one entry removed due to a missing parameter value. (:issue:’440’)

Bug fixes

fixed redeclaration of test_simplified_solis_series_elevation ( GH387 )

physicaliam now returns a Series if called with a Series as an argument. ( GH397 )

corrected docstring for irradiance.total_irrad (:issue: ‘423’)

modified solar_azimuth_analytical to handle some borderline cases, thereby avoiding the NaN values and/or warnings that were previously produced (:issue: ‘420’)

removed RuntimeWarnings due to divide by 0 or nans in input data within irradiance.perez, clearsky.simplified_solis, pvsystem.adrinverter, pvsystem.ashraeiam, pvsystem.physicaliam, pvsystem.sapm_aoi_loss, pvsystem.v_from_i. ( GH428 )

Documentation

Improve physicaliam doc string. ( GH397 )

Testing

Test Python 3.6 on Windows with Appveyor instead of 3.4. ( GH392 )

Fix failing test on pandas 0.22 ( GH406 )

Fix too large test tolerance ( GH414 )

Contributors

Cliff Hansen

Will Holmgren

KonstantinTr

Anton Driesse

Cedric Leroy