Recent rapid progress in wind and solar power marks only the beginning of the renewables revolution. If clean energy is to supplant unabated fossil fuels, especially in the developing world, renewables must become even more affordable and reliable.

There are many exciting opportunities to accelerate innovation in solar photovoltaics, wind, geothermal, concentrating solar, hydro, and marine power technologies.

Advanced renewables that can provide firm power to alleviate the variability plaguing today’s solar PV and wind systems are particularly important to pursue in light of the challenges that face alternatives like nuclear power and carbon capture.

Federal research, development, and demonstration programs in each of the six advanced renewables technology areas should focus on a distinct set of challenges to bring innovations to maturity and jumpstart deployment.

Federal investment must increase significantly if these challenges are to be surmounted rapidly enough for advanced renewables to contribute at scale to the transition to low-carbon energy in the coming decades.