Dec 18, 2008 12:27 PM

Could the Electric Grid Support Far More Wind and Solar?

SAN FRANCISCO — The electric grid may be able to handle more wind and solar power — way more — than previously thought, according to a new preliminary study. The commonly accepted wisdom in the energy industry is that the grid could only draw something like 20 percent of its power from wind and solar […]

SAN FRANCISCO — The electric grid may be able to handle more wind and solar power — way more — than previously thought, according to a new preliminary study.

The commonly accepted wisdom in the energy industry is that the grid could only draw something like 20 percent of its power from wind and solar resources before encountering major reliability problems. But the new power flow simulation(.pdf), presented for the first time this week at the American Geophysical Union meeting, shows that, at least in California, the power grid might be able to handle three times that much renewable energy without encountering major trouble pushing electrons around the state.

"This work has shown that at least 70 percent of the total projected California generation on a summer day in 2016 could be provided by renewable sources ... with relatively minimal upgrades to the transmission infrastructure," wrote Elaine Hart, a Stanford doctoral student, in her presentation. "This study demonstrates the grid-feasibility of a renewable portfolio that far exceeds the target set by the the governor of California."

While these findings are preliminary and only cover a single state, they could help overturn long-held ideas about the plausibility of a world powered by solar and wind plants. The electric grid has remained basically the same since it was built out over the first half of the century. Many people have called for its modernization, by which they mean the addition of new sensors, two-way communication and switches to allow for more sophisticated power routing.

Grid upgrades to support more renewable resources are very costly and a major stumbling block to the increased adoption of wind and solar power. If minor upgrades could allow for far more renewable sources to be added to the grid, it could drop the cost

Hart readily admits that her work is far from complete. The research she presented here at AGU is just the initial findings of a multiyear research project with her Stanford adviser, civil and environmental engineer Mark Jacobson.

One thing that needs work is the set of assumptions about the ease with which natural gas plants could be switched on and off to accommodate variable power from renewable sources. She'd also like to expand the simulations to work over months and years, not just single days.

Photo: dougww/Flickr. Figures: Elaine Hart/Stanford University