geodata.pv.orientation.make_latitude_optimal
============================================

.. py:function:: geodata.pv.orientation.make_latitude_optimal()

   Returns an optimal tilt angle for the given ``lat``, assuming that
   the panel is facing towards the equator, using a simple method from [1].

   This method only works for latitudes between 0 and 50. For higher
   latitudes, a static 40 degree angle is returned.

   These results should be used with caution, but there is some
   evidence that tilt angle may not be that important [2].

   Function and documentation has been adapted from gsee [3].

   [1] http://www.solarpaneltilt.com/#fixed
   [2] http://dx.doi.org/10.1016/j.solener.2010.12.014
   [3] https://github.com/renewables-ninja/gsee/blob/master/gsee/pv.py

   :param lat: Latitude in degrees.
   :type lat: float