Though US president Donald Trump has promised many times that he will bring back coal, he really can’t do much to fight the forces of good old economics.

On Tuesday (Sept. 12), the US Department of Energy announced that utility-grade solar panels have hit 2020 cost targets three years early. Utility-scale solar now averages around $1 per watt (the cost of the hardware’s electricity generation capacity) and $0.06 per kilowatt-hour (the cost of the electricity consumed), targets set in 2011 by the DOE’s SunShot Initiative.

The steady decline in the price of solar power is largely due to falling costs of photovoltaic hardware, driven by market competition, as well as improvements in efficiency, in part stimulated by DOE-funded research, according to a report released by the National Renewable Energy Laboratory on the same day. “Soft” costs like labor have also fallen, but at a slower rate.

Commercial and residential solar have also seen prices drop over time, though each is still 11% and 14% away from meeting their SunShot goals: $0.07 and $0.09 per kWh, respectively.

Having crossed the 2020 milestone, DOE is now setting a new utility-grade solar goal for 2030, redirecting its focus from affordability to “grid reliability, resilience, and storage,” its announcement said. To this end, DOE’s Solar Energy Technologies Office will kick off early-stage research in “power electronics”—technologies that connect solar arrays to the grid—and “concentrating solar power”—technologies that use mirrors to focus sunlight onto a point to generate thermal energy for electricity or heated water. DOE announced $82 million has been committed to these projects.

As of June, according to data from the EIA, solar was accounting for 1.4% of US utility-scale electricity generation in 2017. As costs continue to drop, that number is expected to grow.

Correction: An earlier version of this article incorrectly stated that the DOE’s SunShot Initiative set targets in 2001. The correct year is 2011.