"California becomes first U.S. state to require solar panels on new homes [from 2020]"
http://news.trust.org/item/20180509204651-qp7sa/
"The decision ... came despite estimates it would raise the up-front cost of a new home by nearly $10,000 in one of the most expensive parts of the country.
"The Commission estimated the standards will add about $40 to monthly mortgage payments but will compensate for that by saving residents $80 a month on energy bills."