Note the actual title of the graph is "Wind and Solar have scaled faster ...", which is a big part of the answer. The two techs (and now batteries) are very com

Note the actual title of the graph is "Wind and Solar have scaled faster ...", which is a big part of the answer. The two techs (and now batteries) are very complementary. Also, an underrated factor in cost/benefit of renewables (and nuclear) is interest rates and risk, as you borrow money up front and pay it off over decades. This is a big factor in why Solar is deployed further north than you'd think it should if the earth was being managed by a benelovent dictator. So as costs decrease solar deployment spreads both north and south.