A new study by researchers at the Carnegie Institution for Science finds that clean energy such as wind and solar power, with increased investments in storage and technology, can meet up to 80 percent of energy needs in the United States.
The study, published in Energy & Environmental Science, analyzed 36 years of hourly weather data, from 1980 to 2015, to quantify the natural constraints and variability in solar and wind power. The researchers found that wind and solar energy have a complementary effect of producing higher amounts of energy at different times of the year, making it possible to produce reliable energy for the majority of U.S. energy demand.
"We wanted to do something that was more idealized and simple," says Steven Davis, an associate professor at the University of California–Irvine and a co-author of the study. "The wind doesn't always blow and the sun doesn't always shine. We want our power when we want our power, so we have to come to some accommodation for that actual variability." The researchers evaluated how shifts in the amount of sunlight and wind day-to-day could combine to meet the U.S. demand for electricity.
The study's findings indicate that securing cleaner energy will require investing in building more wind turbines and solar panels, and in more research to find new ways to store large amounts of electricity. The authors also suggest that wind and solar would need to be supplemented by other forms of clean power. However, the Trump administration has focused on developing coal-powered energy and oil production, and has proposed policies that would instead setback clean power industries. The government imposed a 30 percent federal tariff on imported solar panels in January, for example, which halted domestic solar company investments.
Davis says that fossil fuels could be used to make up the remaining 20 percent of energy necessary to meet demand beyond what wind and solar would provide, "because fossil fuels do have that ability to ramp up and down to fill in the gaps, but the long-term goal for a lot of folks it to get to zero emissions." Other generating capacities, such as energy from thermal fuel plants, nuclear fuel plants, or fossil fuel plants with carbon capturing storage could provide for the remaining demand with fewer emissions.
Although 100 percent reliable electricity based in wind and solar power would demand significant changes to energy infrastructure in order to prepare for unpredictable weather events that could impact energy production, this study suggests that a future in entirely clean energy is not impossible.