With Big Solar thermal power plants bogged down in bureaucracy and facing environmental and financial hurdles, utilities are turning to smaller-scale thin-film solar stations that can be built in a matter of months.
In late December, PG&E (PCG), for instance, signed a 20-year contract for electricity generated from a 10-megawatt thin-film solar power plant in Nevada owned by energy giant Sempra (SRE) that was officially dedicated on Thursday. The solar farm was built by First Solar (FSLR) in a scant six months. Meanwhile, the utility’s nearly two gigawatts worth of deals with solar thermal power companies won’t start producing power for another two years at the earliest. (Southern California Edison (EIX) and San Diego Gas & Electric signed agreements with solar dish developer Stirling Energy Systems for 1.75 gigawatts in 2005 and those projects are just now beginning to move through the regulatory approval process.) And the financial crisis has made it more difficult for solar thermal developers to obtain the billions of dollars needed to finance the construction of a massive megawatt power plant.
Solar thermal power plants typically use miles of mirrors to heat a fluid to create steam which drives an electricity-generating turbine. Photovoltaic (or PV) solar farms essentially take solar panels similar to those found on residential rooftops and mount them on the ground in huge arrays. (Thin-film solar panels are made by depositing layers of photovoltaic materials on glass or flexible materials.)
“In terms of construction, photovoltaic tends to have a much faster development and construction track,” Roy Kuga, PG&E’s vice president for energy supply, told Green Wombat. “There is a segment of mid-sized projects – in the two to 20 megawatt size – where PV shows a distinct advantage in that market. There’s a huge potential for the PV market to expand.”
That’s good news for companies like First Solar – the Tempe, Ariz.-based company backed by the Walton family that is often called the Google of solar for its stock price and market prowess – and SunPower (SPWRA), the Silicon Valley solar cell maker that’s moved into the power plant-building business.
The speed at which the Sempra-First Solar project went online owes much to the fact that it was built on the site of an existing fossil fuel power plant. “It was already permitted for power generation, transmission existed and it did not have to go through the laborious California permitting process,” says Reese Tisdale, a solar analyst with Emerging Energy Research. “As such, First Solar was able to essentially plug and play.”
Nathaniel Bullard, a solar analyst with New Energy Finance, says he expects utilities increasingly to bet on smaller-scale photovoltaic farms to help meet state mandates to obtain a growing percentage of their electricity from renewable sources. Just this week, PG&E CEO Peter Darbee said his utility plans to invest in solar power plant projects rather than just buy the power they produce.
“I think a utility could easily integrate, technically and financially, 100 megawatts of PV,” Bullard says. If something is falling behind on your big solar thermal projects, you can plug in PV. I think you’ll see more of this with California utilities and I expect to see it more in Florida and North Carolina. It’s a great runaround to issues of siting and transmission.”
That’s because in California photovoltaic power plants do not need approval from the California Energy Commission. And smaller-scale plants take up far less land and can be built close to existing transmission lines. Most large solar thermal power plants typically are planned for the Mojave Desert and require the construction of expensive power lines to connect them to the grid.
The modular nature of PV solar farms means they can begin generating electricity as each segment is completed while a solar thermal plant only goes online once the entire project is finished.
“Certainly there is a sweet spot in which the project is large enough to gain advantages of scale,” says Tisdale. “Also, these small-to-mid-size systems can be spread about a transmission network, instead of at one site.”