def cloud_cover_to_ghi_linear(self, cloud_cover, ghi_clear, offset=<NUM_LIT>,<EOL>**kwargs):
offset = offset / <NUM_LIT><EOL>cloud_cover = cloud_cover / <NUM_LIT><EOL>ghi = (offset + (<NUM_LIT:1> - offset) * (<NUM_LIT:1> - cloud_cover)) * ghi_clear<EOL>return ghi<EOL>
Convert cloud cover to GHI using a linear relationship.

0% cloud cover returns ghi_clear.

100% cloud cover returns offset*ghi_clear.

Parameters
----------
cloud_cover: numeric
    Cloud cover in %.
ghi_clear: numeric
    GHI under clear sky conditions.
offset: numeric, default 35
    Determines the minimum GHI.
kwargs
    Not used.

Returns
-------
ghi: numeric
    Estimated GHI.

References
----------
Larson et. al. "Day-ahead forecasting of solar power output from
photovoltaic plants in the American Southwest" Renewable Energy
91, 11-20 (2016).