This article was taken from the January 2015 issue of WIRED magazine. Be the first to read WIRED's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online.
Danielle Fong wants to reinvent the power grid -- using air. "We are burning through our carbon budget and temperatures are rising," says the 27-year-old founder of Berkeley-based LightSail Energy. Her solution -- power stored in compressed air tanks. "Air is limitless, inexpensive and lasts a long time compared to batteries," says Fong. Such a device could be plugged into solar and wind farms, where it would hoard and dispatch energy when demand is higher. "The problem with renewables is their unreliability," she says. "They fluctuate with the weather and time of day." LightSail aims to smooth that out -- over the next two years, LightSail's Regenerative Air Energy Storage (RAES) units will be deployed at a half-megawatt scale in California, Hawaii, Canada and the Caribbean, before 20MW units are rolled out in 2017.
Fong, who went to Dalhousie University in Novia Scotia at the age of 12, had worked on nuclear fusion research during her PhD at Princeton, but felt it was moving too slowly. "Where is our energy going to come from? This is an enormously urgent challenge, and there are huge, missing technologies," she says. "It seemed all the money was in Silicon Valley, so I dropped out and moved there to pitch my idea," she says. It worked: so far she has raised $58 million (£36m) from investors including Vinod Khosla, Total Energy, Bill Gates and Peter Thiel.
The process uses electricity to mechanically compress air and store it in a tank. To get energy back, expand the compressed air, which drives a generator to produce AC power. "When you compress air, it gets so hot that you could not store it -- it's 2,000°C at 200 atmospheres," Fong explains. "So we cool it during compression by spraying water into the air and capturing the heat." The warm water is sprayed back in when the air is being expanded. This doubles the current efficiency of this process. "The energy space is a trillion-dollar industry in the making," she says. "So if you think you have an idea for an energy technology, please build it.
It could really transform the world."
This article was originally published by WIRED UK
