In response to Pavel's comments about V2G I have provided some links below for anyone interested in researching this subject further, but be advised that V2G has been around for years.  I was invested in Kandi Technologies years ago before and after they were promoting the idea and it has been picked up by other companies since then.  It will happen in the future because the growth of EVs is such as to provide a potential "Storage Battery" in motion, so to speak for electricity than can be fed back to the Grid, even despite the problem Pavel pointed out abot converting DC current back to AC current.  It is doable, it is practical and it will happen.

http://www1.udel.edu/V2G/V2Gconcept.html

https://blog.technavio.com/blog/what-is-vehicle-to-grid-v2g-and-how-is-it-improving-the-ev-market

https://www.mobilityhouse.com/int_en/vehicle-to-grid

https://www.ovoenergy.com/guides/electric-cars/vehicle-to-grid-technology.html

https://www.cobank.com/knowledge-exchange/power/electric-vehicle-to-grid-integration-from-concept-to-reality

http://www1.udel.edu/V2G/docs/V2G-PUF-LetendKemp2002.pdf

Pavel, I know you like to look at all angles so I am also including a link to a site that is critical of V2G:

https://cleantechnica.com/2016/08/22/vehicle-to-grid-used-ev-batteries-grid-storage/

One more link: from the National Renewable Energy Laboratory.....

https://www.nrel.gov/docs/fy17osti/69017.pdf