I was also going to throw the same curveball:
Trees, when planted BETWEEN the parking spots, don't generate electricity, but apart from that they:
-- give shade in summer, not in winter;
-- absorb large amounts of rain water
-- give a big traffic calming effect;
-- are beautiful and raise property values;
-- make you happy!
Here is an example of how it worked out in this posh street in Bonn, Germany. This same treatment is applied ALL OVER the Netherlands (less posh).