photo: Todd Woody
In an interview I did with green tech entrepreneur Bill Gross for Yale Environment 360, Gross talks about the future of solar energy, his relationship with Google, and how to avoid battles over building large solar farms in the deserts of the Southwest:
Bill Gross is not your typical solar energy entrepreneur. In a business dominated by Silicon Valley technologists and veterans of the fossil fuel industry, Gross is a Southern Californian who made his name in software. His Idealab startup incubator led to the creation of companies such as eToys, CitySearch, and GoTo.com. The latter pioneered search advertising — think Google — and was acquired by Yahoo for $1.6 billion in 2003.
That payday has allowed Gross to pursue his green dreams. (As a teenager, he started a company to sell plans for a parabolic solar dish he had designed.) Over the past decade, Gross has launched a slew of green tech startups, including solar power plant builder eSolar, electric car company Aptera, and Energy Innovations, which is developing advanced photovoltaic technology.
But it has been eSolar, backed by Google and other investors, that has been Idealab’s brightest light. In January, the company signed one of the world’s largest green-energy deals when it agreed to provide the technology to build solar farms in China that would generate 2,000 megawatts of electricity — at peak output the equivalent of two large nuclear power plants. And last week, eSolar licensed its technology to German industrial giant Ferrostaal to build solar power plants in Europe, the Middle East, and South Africa. Those deals followed eSolar partnerships in India and the U.S.
ESolar’s power plants deploy thousands of mirrors called heliostats to focus the sun’s rays on a water-filled boiler that sits atop a slender tower. The heat creates steam that drives an electricity-generating turbine. Last year, eSolar built its first project, a five-megawatt demonstration power plant, called Sierra, in the desert near Los Angeles.
This “power tower” technology is not new, but what sets the company apart is Gross’ use of sophisticated software and imaging technology to control the 176,000 mirrors that form a standard, 46-megawatt eSolar power plant. That computing firepower precisely positions the mirrors to create a virtual parabola that focuses the sun on the tower. That allows the company to place small, inexpensive mirrors close together, which dramatically reduces the land needed for the power plant and cuts manufacturing and installation costs.
“We use Moore’s law rather than more steel,” Gross likes to quip, referring to Intel co-founder Gordon Moore’s maxim that computing power doubles every two years.
You can read the interview here.
Green Wombat 
Todd that was a very good interview. I know a couple of people who went to work for Esolar and it is one of the companies I think might be on the right track when it comes to solar thermal. I operated a couple of the SEGS plants for a few years and know that there are lots of things that could be done to raise efficiency and lower costs. I am also happy to see they are at least thinking about energy storage.
Now one of my problems with Esolar are Gross must have mentioned the word “pristine” four times in that interview. Really almost every environmental writer and anyone else that has a problem with solar-thermal have fallen in love with that word. It is just another way to sensationalize their cause. Brightsource’s project near Primm Nevada is a classic example of this gone amok. They talk about the “pristine” land but go out of their way to not show the golf course next door, the transmission lines, the three casinos and another power plant all very close to the project. It is pretty obvious from this interview and other press releases from Esolar they are trying to beat the “pristine” drum against their competitors. The problem with that is all energy projects have environmental and community concerns. I am not sure Esolar wants to have that drum beat against them.
I also feel that Gross may be underestimating the operating costs of a solar plant. Yes the fuel is essentially free but mirrors get broken, tracking units need to be replaced, and they can be fairly labor intensive, although to be fair so are coal plants.
Thanks, Steve. I wrote about how BrightSource Ivanpah’s site is not in a “pristine” patch of the desert in a previous story for Yale Environment 360: http://www.e360.yale.edu/content/feature.msp?id=2236