The Hawaii legislature has just passed a bill by an overwhelming margin that sets a goal of 100% renewable energy in the state by 2045. The new law requires that the state get a third of its electricity from renewables by 2020, only five years from now. Electricity in Hawaii is expensive, about 34 cents a kilowatt hour for residences, since unlike most states it depends on petroleum as the fuel for its plants, and that has to be imported across long distances. The US average cost for residential electricity is 12 cents a kilowatt hour. New solar installations can provide it as low as 6 cents a kilowatt hour, and new geothermal plants are slightly cheaper (Hawaii has a *lot* of potential geothermal power but there is substantial public resistance, and solar may be the better play). So the legislature’s plan is the only thing that makes sense, and if anything its timeline is not nearly ambitious enough. Even a developing country like Morocco plans for 42% renewables by 2020, and Scotland may well be 100% by then. Costa Rica already is.
China put in 5 gigawatts of new solar plants in the first three months of 2015 alone. In all of 2014, the USA did not install that much new solar, and 2014 was a remarkably good year for solar power in the US. China is near to outstripping Germany for title of country with the most solar energy. It will likely have 45 gigwatts of solar generation capacity by the end of 2015, 10 gigs more than it had planned for.