The Energy Information Administration (EIA) has released numbers on US electricity generation for the first quarter of 2017, and renewable energy numbers are coming in big.

According to the EIA, renewable energy sources like wind, solar, and geothermal power accounted for 10.68 percent of total electricity generation in the first quarter of 2017. If you include electricity from conventional hydroelectric plants, renewables made up nearly a fifth of total electricity generation—as much as 19.35 percent.

The striking part about that number is that the EIA, a statistical department within the Department of Energy, couldn’t foresee how dramatically renewables’ share of the electricity mix would increase just five years ago. In 2012, the administration predicted (PDF, page 87) that electricity generation from renewable sources would increase “from 10 percent in 2010 to 15 percent in 2035.” Even by 2015, the administration predicted (PDF, page ES-6) that “The renewable share of total generation grows from 13 percent in 2013 to 18 percent in 2040.”

Non-profit organization Sun Day Campaign said in a statement that, if the EIA were to extend its 2012 renewable growth forecast further out into the future, “renewables would not be expected to reach 19.35 percent until roughly the year 2057.”

The renewable energy numbers for the first quarter of 2017 include about 4.786 TWh of residential and small-scale solar electricity, as well as 9.2 TWh of utility-grade solar electricity. In the previous year's first quarter, utility-grade solar generated only 6.67 TWh of electricity, meaning utility-grade solar electricity generation increased 38.5 percent year over year.

The EIA’s projections didn’t foresee the explosion of solar installations caused by compelling federal tax incentives combined with plummeting photovoltaic costs. Instead, five years ago, economists were predicting that “most of the growth in renewable electricity generation comes from wind and biomass facilities.”

Wind certainly contributed a major proportion of renewable energy in the first three months of 2017 (67.64 TWh), but biomass faltered, with wood and wood-derived fuels losing 1.2 percent of the total electricity generation year over year. “Other biomass” lost 2.3 percent of the share it had in 2016.

For the entire year, the renewable energy portion of total electricity generation won’t track exactly with the first quarter of the year. Solar might increase as the days get longer and sunnier, while hydro could fall behind if any reservoirs experience droughts. Depending on where you are in the country, wind can become more variable in the summer.

Outside of renewable energy, nuclear power plants provided 1 percent less electricity, year-over-year. Older nuclear facilities have been facing retirement (like the recently-announced planned retirement of Three Mile Island in 2019), while newer and proposed nuclear plants have faced stiff competition from cheap wind and natural gas. Earlier this year, the status of three proposed nuclear plants was thrown into question as Westinghouse, the reactor builder owned by Toshiba, declared bankruptcy.

Coal also saw a 5-percent bump in the first quarter of 2017 from the first quarter of 2016, but it was a bump that was largely expected by economists due to demand for natural gas. Natural gas has been incredibly cheap, driving up demand. As demand goes up, some electricity purchasers have turned back to coal in the short term. But the Institute for Energy Economics and Financial Analysis says that bump is short-lived, barring dramatic policy intervention.

Correction: The watt-hours generated in the first quarter of 2017 have been corrected from GWh to TWh.