A technology that concentrates sunlight to boost the power production of solar cells hasn’t gotten a lot of respect in the past. But in recent months it’s been getting a growing amount of attention and interest thanks to a series of projects, power contract announcements and a $90.6 million federal loan guarantee offered to build a 30 MW solar power plant in Colorado.
Worldwide, about 690 MW of so-called concentrating photovoltaic (CPV) power plant projects are in development, including 28 MW in operation, 41 MW under construction, and another 621 MW under development, both with and without power contracts in place, said Brett Prior, senior analyst with GTM Research, during a webinar on Thursday. Most of them are being built in the U.S.
Those numbers should make developers of competing solar technologies take notice, even if they are small in comparison to the number and size of projects that use conventional solar panels or technologies that use the sun’s heat to produce steam and run turbine-generators. It was only a year ago when the largest, operating CPV project in the U.S. reached 1 MW and the largest to date in operation is currently 2 MW.
“CPV is moving forward with a number of projects and that’s terrific news,” Prior said. “When you start with such a low base in terms of installed capacity and you are ramping up, there’s a lot of room for improvement on cutting cost out of the supply chain and improvements in installation cost.” Even though less than 5 MW of CPV have been added each year so far, the number of CPV projects should jump to more than 1000 MW in 2015 globally, Prior said.
CPV technology developers have always maintained that their equipment can deliver electricity at comparable costs to other solar technologies. But that promise is largely based on projections, which present no small amount of risks to developers and their banks. Plus, technology companies also haven’t always achieved the advancements they’ve wanted by the deadlines they’ve set for themselves. The three technology front runners are Amonix, SolFocus and Soitec’s Concentrix.
Technology improvements in areas like the efficiencies of solar cells, the optics that can more precisely concentrate and beam sunlight onto the cells, and the design of the solar panels and trackers that rotate the panels to follow the sun’s movement throughout the day, have made a big difference in CPV’s acceptance. CPV aims to cut costs by using slivers of solar cells that can covert around 39 percent of the sunlight into electricity. The use of trackers helps to boost power generation, particularly in the afternoon when the performance of conventional, stationary solar panels can drop significantly, Prior said.
Most conventional solar panels today use silicon, and the most efficient silicon solar cells on the market today can do 23 percent. SunPower pairs trackers with its own silicon solar panels, and the company is working on its own CPV technology. First Solar, which makes cadmium-telluride solar panels that are less efficient than the silicon variety, bought a tracker company earlier this year and is building a 20 MW project in New Mexico that will be the first to use trackers, CEO Rob Gillette said earlier this month.
CPV’s mirrors and lenses don’t work well in concentrating and direct diffuse light, however, so CPV projects need to find home in places that are very sunny and not many clouds to block the sun. CPV equipment is heavy and largely designed to be mounted on the ground, not the rooftop, so that further restricts where they can be installed.
Lining up financing for a new type of technology is always challenging, and CPV is no different. CPV is garnering attention lately partly because it’s gotten major financial backing from the federal government. The Department of Energy is offering a $90.6 million loan guarantee to Cogentrix, which plans to use Amonix’s solar technology for the 30 MW project. Amonix used federal tax credits of $5.9 million to help build an $18 million factory, which recently opened in Nevada.
Although CPV is attracting some project developers who are well known in their main businesses – Tenaska in fossil fuel power generation and Soitec in semiconductor manufacturing – many CPV project developers are small and have no money of their own to finance construction, Prior said. Attracting larger developers that can use their own money to finance projects instead of relying mostly on banks and the government will be a major boost for CPV technology. SunPower, for one, is selling a 60 percent stake of the company to French oil and gas company, Total, a deal that could help SunPower to accelerate the development and deployment of its CPV technology.
Technology developers certainly are getting more equity investment from investors who can help finance deployment later on. Canada-based Morgan Solar said Thursday it has raised $16.5 million from investors such as Spain-based Iberdrola, one of the world’s largest utilities.
San Diego Gas & Electric has become a big patron in the CPV world. The utility said it had signed five contracts to buy 155 MW of electricity from Soitec, which bought CPV technology developer Concentrix in 2009. Soitec is promising to build a 200 MW factory to produce CPV equipment in San Diego. SDG&E also has signed two contracts to buy a total of 280 MW from Tenaska.
Photo courtesy of SolFocus