Solar and wind could reliably provide roughly 80 percent of the US’s electric demand. That’s according to a new study from the University of California, Irvine (UCI); the California Institute of Technology; and the Carnegie Institution for Science.
“The fact that we could get 80 percent of our power from wind and solar alone is really encouraging,” said Steven Davis, UCI associate professor of Earth system science and co-author of the study. “Five years ago, many people doubted that these resources could account for more than 20 or 30 percent.” Wind and solar are quickly adding electric generation to the grid.
That’s significantly higher than many studies have previously anticipated, the researchers found that without significant changes, including significant amounts of energy storage, the US could not transition to 100 percent wind and solar. The universities published their work, based on 36 years of hourly US weather data (1980 to 2015), in the peer-reviewed journal Energy & Environmental Science. To reach that level of solar and wind, power the US would have to be able to store several weeks’ worth of electricity.
“We looked at the variability of solar and wind energy over both time and space and compared that to U.S. electricity demand,” Davis said. “What we found is that we could reliably get around 80 percent of our electricity from these sources by building either a continental-scale transmission network or facilities that could store 12 hours’ worth of the nation’s electricity demand.”
The study found that other forms of energy storage, like pumped water, are not viable for most of the US. As such, until the US makes such a transition, the study found fossil fuels will remain a part of the electric generation mix. Currently fossil fuel-based electric generation produces about 38 percent of the country’s carbon dioxide emissions, the study found.
Stil, building the transmission network to enable such high levels of wind and solar would require substantial investments—hundreds of billions of dollars. That would still be far less than the more than trillion dollar investment it would take to add that much energy storage using current batteries, the researchers stated.
“Our work indicates that low-carbon-emission power sources will be needed to complement what we can harvest from the wind and sun until storage and transmission capabilities are up to the job,” said co-author Ken Caldeira of Carnegie. “Options could include nuclear and hydroelectric power generation, as well as managing demand.”Tweet