Joshua D. Rhodes, University of Texas at Austin
President Joe Biden has called for major clean energy investments as a way to curb climate change and generate jobs. On Sept. 8, 2021, the White House released a report produced by the U.S. Department of Energy that found that solar power could generate up to 45% of the U.S. electricity supply by 2050, compared to less than 4% today. We asked Joshua D. Rhodes, an energy technology and policy researcher at the University of Texas at Austin, what it would take to meet this target.
Why such a heavy focus on solar power? Doesn’t a low-carbon future require many types of clean energy?
The Energy Department’s Solar Futures Study lays out three future pathways for the U.S. grid: business as usual; decarbonization, meaning a massive shift to low-carbon and carbon-free energy sources; and decarbonization with economy-wide electrification of activities that are powered now by fossil fuels.
It concludes that the latter two scenarios would require approximately 1,050-1,570 gigawatts of solar power, which would meet about 44%-45% of expected electricity demand in 2050. For perspective, one gigawatt of generating capacity is equivalent to about 3.1 million solar panels or 364 large-scale wind turbines.
The rest would come mostly from a mix of other low- or zero-carbon sources, including wind, nuclear, hydropower, biopower, geothermal and combustion turbines run on zero-carbon synthetic fuels such as hydrogen. Energy storage capacity – systems such as large installations of high-capacity batteries – would also expand at roughly the same rate as solar.
One advantage solar power has over many other low-carbon technologies is that most of the U.S. has lots of sunshine. Wind, hydropower and geothermal resources aren’t so evenly distributed: There are large zones where these resources are poor or nonexistent.
Most areas of the U.S. can generate at least some solar power