The Week in Solar Energy

Difficult times, but innovation is continuing.

Solar concentrate does not need tracking sun

  • The Massachusetts Institute of Technology (MIT) of the US has developed a light concentration system for solar cells that does not track the sun. The method can utilize display glass and even window glass in homes, office buildings, etc, as sunlight concentrators. In addition, said a source at MIT, it makes it possible to drop the cost of the solar cell system to a tenth or less.

Grätzel cells advance

  • Dye-sensitized solar cells, sometimes called Grätzel cells after their inventor, Michael Grätzel, a chemistry professor at the École Polytechnique Fédérale de Lausanne, in Switzerland, have long been considered a promising technology for reducing the cost of solar power. They’re potentially cheaper to make than conventional solar cells and can be quickly printed. But this potential hasn’t been realized because to achieve efficiency levels high enough to compete with conventional solar cells–about 10 percent–it’s been necessary to use volatile electrolytes that need to be carefully sealed inside the cells, an expensive and unreliable step in the manufacturing.
  • Now Grätzel, along with Peng Wang, a professor at the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, have made efficient solar cells that use nonvolatile electrolytes, with the best achieving efficiencies of 10 percent. They also showed that the solar cells remained stable when exposed to light and high temperatures for 1,000 hours. The advance “pushes the technology close to over the ’10 percent hump,’ which is where a thin-film technology needs to be to be economically competitive,” says Tonio Buonassisi, a professor of mechanical engineering at MIT.

In downturn, solar industry sees bright days ahead

  • SAN DIEGO–People in the solar industry are hopeful that the sun is a good place to put money these days. To be sure, the financial crunch is rippling through even the fast-growing solar business: With falling house prices and general belt-tightening, consumers may be more reluctant to purchase solar panels, even if they want renewable electricity. And less available capital makes it difficult to finance large-scale projects, like corporate rooftop arrays or solar power plants. But even with the gloomy economic outlook, the mood at this week’s Solar Power International 2008 conference was decidedly upbeat. The solar industry scored a major policy win, getting an eight-year extension to federal tax credits that tacked on more generous terms for homeowners.
  • And in a volatile investment environment, solar looks solid, purely from a financial point of view, many executives argued. “I think there’s a flight to quality and we believe there’s a flight to solar because of that,” said Tom Werner, the CEO of California-based solar panel manufacturer and installer SunPower. He noted that big solar projects over the past three or four years have created a track record of delivering expected financial returns.

Start-up tries to manufacture a solar revolution

  • LEXINGTON, Mass.–1366 Technologies is a 20-person start-up that’s chasing an ambitious goal–making solar power cheaper than coal-made electricity–through a series of small steps.
  • The company on Thursday hosted a ribbon-cutting ceremony here at its pilot facility plant, where its engineers are making changes to standard solar cell production to cut the cost of solar power to less than $1 per watt.1366 Technologies’ approach of layering on small efficiency gains to standard silicon cells has received positive reviews from solar industry watchers.
  • It is commercializing technology developed at the Massachusetts Institute of Technology by professor Ely Sachs. Sachs, now the chief technology officer of 1366 Technologies, on Thursday said that the company has a pipeline of improvements, each meant to build off the other, all while using incumbent silicon solar technology.
  • It’s less flashy than pursuing radically new ideas, but the company projects that–with sufficient funding–it can hit its less-than-coal mark by about 2015, said President Frank van Mierlo.
  • “These are all basically manufacturing ideas–it’s not new materials or trying to industrialize photosynthesis through some unlikely process,” van Mierlo said. “It’s just hammering away at manufacturing costs.”
  • The company raised $12.4 million earlier this year on the basis of a light-capturing method. A “grooved ribbon” wire is placed below solar cells to reflect light back onto the cell that would otherwise be lost. That technology is being licensed to other cell manufacturers, van Mierlo said.
  • At its Lexington facility, company engineers are now testing what they refer to as “idea No. 2,” using copper rather than silver-based wiring, which will improve electrical conductivity, van Mierlo explained.

SolarWorld claims N. America’s largest solar manufacturing facility

  • Hillsboro, Ore. — SolarWorld has opened its new plant in Hillsboro, Oregon, claiming it’s the largest solar cell manufacturing facility in North America. The new plant is expected to reach a capacity of 500 megawatts (MW) and employ 1,000 people by 2011. The solar industry is expected to grow to $74 billion in 2017 from $20 billion in 2007, according to Clean Edge Inc., a market research firm focused on clean technology.

Sun + Water = Fuel

  • With catalysts created by an MIT chemist, sunlight can turn water into hydrogen. If the process can scale up, it could make solar power a dominant source of energy. Solar power has a unique potential to generate vast amounts of clean energy that doesn’t contribute to global warming. But without a cheap means to store this energy, solar power can’t replace fossil fuels on a large scale. In Nocera’s scenario, sunlight would split water to produce versatile, easy-to-store hydrogen fuel that could later be burned in an internal-combustion generator or recombined with oxygen in a fuel cell. Even more ambitious, the reaction could be used to split seawater; in that case, running the hydrogen through a fuel cell would yield fresh water as well as electricity.