Underground energy storage could solve US renewable energy transition

The United States could solve the complete transition to renewable energy by combining it with underground energy storage, according to a new Stanford study. Stanford professor of civil and environmental engineering, Mark Jacobson, and colleague Mark Delucchi of the University of California, Berkeley, have been working on a series of plans that — state-by-state — show how the US could shift entirely from fossil fuel to renewable energy.

In a new study published this week in the Proceedings of the National Academy of Sciences, the two show how a transition to a reliable, affordable national grid powered by renewable energy is possible when combined with inexpensive storage and “demand response.”

Specifically, Jacobson and Delucchi propose a system that relies on the ability to store and retrieve heat, cold, and electricity in order to meet demand at all times. Summer heat would be gathered in rooftop solar collectors and stored in soil or rocks for use in heating homes during winter, while low-cost electricity would make ice, which would then be used down the track for cooling with the price of electricity is high.

“The utilities and others who are against renewables have always argued that the lights are going to go out, the grid is going to be unstable, and it will cost too much to keep a clean, renewable-energy grid stable and reliable,” Jacobson said. “Skeptics have never studied a system of 100 percent clean, renewable energy for all purposes, and particularly one that combines low-cost storage with demand response and some hydrogen, as in this new paradigm.”

In addition, hydrogen would be used as a storage medium for use later on to power vehicles. “Demand response” — wherein utilities give customers incentives to control times of peak demand — would be used in conjunction with the storing of electricity, heat, and cold to smooth out any uneven patches caused by the inherent flexibility of most renewable energy technologies.

All in all, Jacobson’s plan has tremendous benefits across the board.

“You eliminate air pollution and global warming emissions, stabilize fuel costs, create over two million more jobs than are lost in the U.S., you reduce reliance on international trade of fuels, and you reduce the risk of power disruption, such as from terrorism or massive failure, because more energy is distributed over larger areas,” Jacobson said. “Most energy would be local. You can eliminate a lot of fuel emissions, just because you won’t have to transport oil in tankers across the ocean, you won’t have to use trains of coal cars to ship the coal.” 

http://cleantechnica.com/2015/11/25/underground-energy-storage-solve-us-renewable-energy-transition/