Global environmental challenges
Utility makes big bets on solar technology
As solar panel prices have plummeted over the past year, photovoltaic power plants have become a more attractive option for utilities under pressure to meet renewable energy targets.
Case in point: Late last week utility Southern California Edison announced it had signed contracts for 239.5 megawatts of electricity to be generated by 20 small-scale photovoltaic farms.
“Photovoltaics are definitely more cost competitive than they were just a couple of years ago,” said Mike Marelli, director of contracts for renewable and alternative power at Southern California Edison. “We’re seeing just a wild response to our solicitations for projects.”
The utility has inked deals in past years for huge solar thermal power plants that can generate 500 megawatts or more. But those projects — which focus large arrays of mirrors on liquid-filled boilers to generate steam that drives electricity-generating turbines – need vast stretches of desert land. Transmission lines must often be built or upgraded to carry the power to coastal cities.
The photovoltaic farms, ranging in size from five megawatts to 20 megawatts, are designed to be built near existing transmission lines or substations and plugged into the grid. And in California, for instance, photovoltaic power plants do not undergo the extensive environmental review required of big solar thermal projects, meaning they can be built much more quickly.
In the power purchase agreements reached last wee, Southern California Edison also for the first time placed bets on a technology known as concentrating photovoltaics – -CPV — signing contracts for 28.5 megawatts of electricity to be generated by four projects using technology supplied by Amonix, a Seal Beach, Calif., company.
Resembling supersized solar panels, each Amonix CPV power generator is 77 feet by 50 feet and produces 72 kilowatts of electricity by using plastic lenses to focus the sun on tiny but highly efficient solar cells.
The panels are more efficient than conventional photovoltaic modules but high production costs, technological challenges and other hurdles had kept CPV on the sidelines with just a few small installations operating around the world.
The 40 percent price drop in photovoltaic modules over the past year has not affected the competitiveness of CPV so much as the surmounting of technological obstacles. With CPV now ready for more widespread deployment, investors have poured money into Amonix. In April, the startup raised $129.4 million from venture capital firms led by Silicon Valley’s Kleiner Perkins Caufield & Byers.
“The economics are getting into a point where solar PV and CPV if put on the right sites is competitive with the cost of peaking natural gas generation,” said Brian Robertson, Amonix’s chief executive.
As is the case with solar thermal plants, CPV works best in high desert areas with intense sunshine. But unlike some solar thermal technologies, it consumes a minimal amount of water.
Amonix has kept a low profile as it prepares to open a factory in Las Vegas early next year to manufacture its solar systems.
“There are so many projects where people announce a pipeline but putting metal in the ground is another matter,” said Robertson. “Financing a real asset is a much taller task.”
Amonix’s technology is also being used in two solar projects under construction in Arizona as well as for a power plant in Colorado.
Marelli of Southern California Edison said the while the utility evaluates the viability of solar technologies for proposed projects it does not specify which a developer should deploy.
“We cast a wide net and we let the market send us proposals and options to consider,” he said. “We have such a large portfolio we can offer an opportunity to some of these new technologies and give them a shot to move forward.”
(Photo courtesy of Amonix.)