0.4.1

This is a minor release from 0.4.0. We recommend that all users upgrade to this version, especially if they want to use the latest versions of pandas.

Bug fixes

• Fixed an error in the irradiance.klucher transposition model.
  The error was introduced in version 0.4.0. (:issue:228)
• Update RAP forecast model variable names. (:issue:241)
• Fix incompatibility with pandas 0.19 and solar position calculations.
  (:issue:246)

Documentation

• Fixed a typo in the pvsystem.sapm returns description. (:issue:234)
• Replaced nosetests references with py.test. (:issue:232)
• Improve the rendering of the snlinverter doc string. (:issue:242)

Code Contributors

• Mark Mikofski
• Johannes Dollinger
• Will Holmgren

0.4.0

This is a major release from 0.3.3. We recommend that all users upgrade to this version after reviewing the API Changes. Please see the Bug Fixes for changes that will result in slightly different modeling results.

API Changes

Remove unneeded module argument from singlediode function. (GH200)
In pvlib.irradiance.perez, renamed argument modelt to model. (GH196)
Functions in the irradiance module now work with scalar inputs in addition to arrays and Series. Furthermore, these functions no longer promote scalar or array input to Series output. Also applies to atmosphere.relativeairmass. (GH201, GH214)
Reorder the ashraeiam, physicaliam, and snlinverter arguments to put the most variable arguments first. Adds default arguments for the IAM functions. (GH197)
The irradiance.extraradiation function input/output type consistency across different methods has been dramatically improved. (GH217, GH219)
Updated to pvsystem.sapm to be consistent with the PVLIB MATLAB API. pvsystem.sapm now takes an effective irradiance argument instead of POA irradiances, airmass, and AOI. Implements closely related sapm_spectral_loss, sapm_aoi_loss, and sapm_effective_irradiance functions, as well as PVSystem methods. The sapm_aoi_loss function includes an optional argument to apply an upper limit to the output (output can be ~1% larger than 1 for AOI of ~30 degrees). (GH198, GH205, GH218)
The pvsystem.retrieve_sam keyword argument samfile has been replaced with path. A selection dialog window is now activated by not supplying any arguments to the function. The API for typical usage remains unchanged, however, the data will be loaded from a local file rather than the SAM website. (GH52)

Enhancements

Adds the First Solar spectral correction model. (GH115)
Adds the Gueymard 1994 integrated precipitable water model. (GH115)
Adds the PVWatts DC, AC, and system losses model. (GH195)
Improve PEP8 conformity in irradiance module. (GH214)
irradiance.disc is up to 10x faster. (GH214)
Add solarposition.nrel_earthsun_distance function and option to calculate extraterrestrial radiation using the NREL solar position algorithm. (GH211, GH215)
pvsystem.singlediode can now calculate IV curves if a user supplies an ivcurve_pnts keyword argument. (GH83)
Includes SAM data files in the distribution. (GH52)
ModelChain now implements SAPM, PVWatts, Single Diode and user-defined modeling options. See Will Holmgren’s ModelChain refactor gist for more discussion about new features in ModelChain. (GH143, GH194)
Added forecast.py module for solar power forecasts. (GH86, GH124, GH180)

Bug fixes

Fixed an error in pvsystem.singlediode’s i_mp, v_mp, and p_mp calculations when using array or Series input. The function wrongly returned solutions when any single point is within the error tolerance, rather than requiring that the solution for all points be within the error tolerance. Results in test scenarios changed by 1-10%. (GH221)
Fixed a numerical overflow error in pvsystem.singlediode’s v_oc determination for some combinations of parameters. (GH225)
dirint function yielded the wrong results for non-sea-level pressures. Fixed. (GH212)
Fixed a bug in the day angle calculation used by the ‘spencer’ and ‘asce’ extraterrestrial radiation options. Most modeling results will be changed by less than 1 part in 1000. (GH211)
irradiance.extraradiation now raises a ValueError for invalid method input. It previously failed silently. (GH215)
Documentation
Added new terms to the variables documentation. (GH195)
Added clear sky documentation page.
Fix documentation build warnings. (GH210)
Removed an unneeded note in irradiance.extraradiation. (GH216)

Other

pvlib-python is now available on the conda-forge channel: conda install pvlib-python -c conda-forge (GH154)
Switch to the py.test testing framework. (GH204)
Reconfigure Appveyor CI builds and resolve an issue in which the command line length was too long. (GH207)
Manually build numpy and pandas for the min requirements test. This is needed to avoid Continuum’s bad practice of bundling scipy with pandas. (GH214)

Requirements

pvlib now requires pandas >= 0.14.0 and numpy >= 1.9.0, both released in 2014. Most of pvlib will work with lesser versions. (GH214)

Code Contributors

Will Holmgren
Jonathan Chambers
Mitchell Lee
Derek Groenendyk

0.3.3

This is a minor release from 0.3.2. Highlights include:

• Renamed series_modules to modules_per_string and
  parallel_modules to strings_per_inverter. (:issue:176)
• Adds the scale_voltage_current_power function and PVSystem method
  to support simple array modeling. (:issue:159)
• Adds support for SingleAxisTracker objects in ModelChain.
  (:issue:169)
• Add __repr__ method to PVSystem, LocalizedPVSystem, ModelChain,
  SingleAxisTracker, Location. (:issue:142)
• Improve speed of singlediode function by using v_from_i to
  determine v_oc. Speed is ~2x faster. (:issue:190)
• Adds the Simplified Solis clear sky model. (:issue:148)
• Fix problem in which the perez function dropped nighttime values.
  Nighttime values are now set to 0.
  (:issue:191)
• Localize datetime indices in package overview examples.
  (:issue:156)
• Clarify that ModelChain and basic_chain currently only
  supports SAPM. (:issue:177)
• Shorten README.md file and move information to official documentation.
  (:issue:182)
• Change authors to PVLIB Python Developers and clean up setup.py.
  (:issue:184)

Contributors

• Will Holmgren
• Mark Mikofski
• Johannes Oos
• Tony Lorenzo

0.3.2

Update the SAM file url.

0.3.1

This is a bug fix release. See the 0.3.1 whats new documentation for details.

0.3.0

This is a major release from 0.2.2. It creates a cleaner separation between the use of procedural and object oriented code by changing the way that Location objects are used and adding ModelChain, PVSystem, LocalizedPVSystem classes. See the What's New documentation for much more.

0.2.2

This is a minor release from 0.2.1. It adds Python 3.5 compatibility, a lookup_linke_turbidity function, and fixes several small bugs.

0.2.1

This is a minor release from 0.2. It includes a large number of bug fixes for the IPython notebook tutorials and links to updated SAM files.

0.2.0

v0.2.0 (July 6, 2015)

This is a major release from 0.1 and includes a large number of API changes,
several new features and enhancements along with a number of bug fixes.
We recommend that all users upgrade to this version.

Due to the large number of API changes, you will probably need to update your
code.

API changes

• Change variable names to conform with new
  Variables and style rules wiki <https://github.com/pvlib/pvlib-python/wiki/Variables-and-style-rules>_.
  This impacts many function declarations and return values.
  Your existing code probably will not work! (:issue:37, :issue:54).
• Move dirint and disc algorithms from clearsky.py
  to irradiance.py (:issue:42)
• Mark some pvsystem.py methods as private (:issue:20)
• Make output of pvsystem.sapm_celltemp a DataFrame (:issue:54)

Enhancements

• Add conda installer
• PEP8 fixups to solarposition.py and spa.py (:issue:50)
• Add optional projection_ratio keyword argument to the haydavies
  calculator. Speeds calculations when irradiance changes but
  solar position remains the same (:issue:58)
• Improved installation instructions in README.

Bug fixes

• fix local build of the documentation (:issue:49, :issue:56)
• The release date of 0.1 was fixed in the documentation
  (see :ref:whatsnew_0100)
• fix casting of DateTimeIndex to int64 epoch timestamp on machines with 32 bit python int (:issue:63)
• fixed some docstrings with failing doctests (:issue:62)

Contributors

• Will Holmgren
• Rob Andrews
• bmu
• Tony Lorenzo