Federal Government Wakes Up To Surging Rooftop Solar

Like a rocket on a radar screen, small-scale solar energy has muscled its way into the government's meticulous portrayal of the energy landscape.
For many years, the U.S. Energy Information Administration only released annual estimates of solar installations on homes and businesses, which once added little to the country's energy portfolio. It was a sign of things to come at the end of 2015 when the agency began tracking small solar installations monthly. Last week analysts began adding growth forecasts for the technology to EIA's closely watched Short-Term Energy Outlook, and the forecasts are robust.
"These small-scale PV installations are also called behind-the-meter, customer-sited, or distributed generation capacity," EIA analysts April Lee and Carolyn Moses write. "Although each distributed PV system is very small—a typical size for residential PV systems is 5 kilowatts (kW), or 0.005 MW—there are hundreds of thousands of these systems across the country that add up to a substantial amount of electricity generating capacity."
EIA estimates that U.S. small-scale solar PV electricity generation reached 19,467 gigawatthours (GWh) in 2016, will achieve 25,400 GWh this year and 32,900 GWh in 2018. It's worth mentioning that EIA forecasts of renewables have often proven overly conservative.
More than half of the growth in small-scale solar is occurring in the residential sector, with about 32 percent in commercial and 8 percent in industrial.
But solar is growing on the large scale too. Large utility-owned installations are still about double the small-scale numbers. EIA expects utility-scale solar to provide 50,800 GWh this year.
Solar has begun to make a visible dent in total electricity generation, but it's still a tiny dent: in April solar represented about 1.6 percent of electricity generated in the U.S., according to EIA.
Small-scale solar has not developed evenly across the states. California lead the nation with 41 percent of the nation’s total small-scale PV capacity in 2016. New Jersey, Massachusetts, and Arizona rounded out the top four, together representing another 24 percent, EIA says. Many more states are contributing much less.
EIA's inclusion of small-scale solar statistics could mark a shift in attention from centralized, utility-owned power generation to a world in which many make their own electricity.