Thirty states and the District of Columbia now mandate minimum levels of electricity be generated from renewable sources such as wind and solar. These so-called renewable energy standards  are set to usher in massive increases in renewables nationwide, largely as an effort to combat climate change. But unless U.S. policymakers make swift changes, there's little chance the U.S. power grid will be able to accommodate those renewables, according to a report released today from the American Physical Society (APS).
"The good news is that the U.S. has significant solar and wind resources. But if we want to increase our use of these resources, we have some homework to do," says James Misewich, the associate lab director for basic energy sciences at Brookhaven National Laboratory in Upton, New York, and a co-chair of the report. Unless the country is willing to put up with a steady diet of blackouts and brownouts, electricity must be delivered in steady, reliable doses. That's easy to do with coal plants and natural gas turbines. But renewables send power full blast at some times and none at all at others. Another problem is that the best wind- and solar-generation sites are in the Midwest and Southwest, far from the energy-hungry population centers on the east and west coasts.
There's plenty that energy officials can do to overcome these problems, the report says.
First, the U.S. Department of Energy (DOE) should back research efforts to store large amounts of power for the grid. (The report doesn't specify how much this increase should be.) It should support research on high-temperature superconductors, focusing on using them to create direct current superconducting cables for long-distance power transmission. DOE should also fund the development of novel electronics devices for controlling the flow of power on the grid. Other agencies, meanwhile, should encourage efforts to improve weather forecasts to help grid operators keep power generation steady.
The U.S. Congress is currently considering whether to implement a national renewable electricity standard. A measure for such a standard was introduced this past summer in the U.S. Senate. But as of now the bill doesn't appear  to have the 60 votes needed to make it out of the chamber. If a national standard does pass, Misewich says that a key recommendation from the report is that any such standard should be phased in over time to address these challenges. "That is key—otherwise, we will be setting ourselves up for failure," Misewich says.
The APS report is here .