A team of photochemical cooks at the Ecole Polytechnique Federale de Lausanne in Switzerland have whipped up a batch of inexpensive solar cells that could revolutionize solar energy. The “Dye-sensitized Solar Cells” use dye and an electrolyte solution to harness solar radiation to make electricity. The components are sandwiched together to form a flexible film that’s durable and long lasting.
Professors Michael Grätzel and Brian O’Regan invented the solar cells in 1991, but only recently developed an easy, low-cost way to manufacture them. So how do they work? The cells consist of a porous film of white, nanometer-sized titanium dioxide particles covered in a dark dye. The film is suspended in an electrolyte solution. When sunlight hits the dye, it injects an electron (negative charge) into the titanium particles.
Grätzel and his team have tweaked the manufacturing process, nixing the volatile organic solvents that typically make up the electrolyte solution in favor of a mixture of three salts. The bottom line: Dye-sensitized cells that can be made on the cheap without harsh solvents.
The new salt-based dye-sensitized cells have an efficiency of about 8.2 precent, a little more than half the efficiency of silicon-based photovoltaic cells. No official word on cost, but Grätzel and friends claim that their panels will be considerably cheaper than traditional solar cells. They should also last more than 10 years, says Grätzel.
San Jose powerhouse Nanosolar has improved the efficiency of their printable solar cells, made from nanoparticle ink. The company now claims it can pump out enough solar panels every year to harness 1 gigawatt of power from the sun. Still not enough to power the Flux Capacitor (1.21 GW), but it would put a considerable dent in U.S. power usage. The typical U.S. home consumes about 8,900 kilowatt hours per year.
We spend a lot of time and energy trying to keep light out of our homes. When the sun blazes, we pull the shades, blocking sunlight that would normally turn our dwellings into sweltering greenhouses. Designer Shelia Kennedy believes that instead of deflecting all that energy, we could harness it. She’s invented “solar curtains,” sheets of flexible fabric with imbedded thin-film photovoltaic solar cells.
The designer and her team at KVA Matix have also sketched a house that can theoretically nab up to 16,000 watt-hours of electricity using the curtains. They call it the “Soft House.” The home hasn’t been built yet, but the photovoltaic curtains are in development.
In a delightful marriage of engineering and slap-schtick puns, a team of Japanese electronic miracle workers have developed a literal solar plant—an artificial houseplant that harvests electricity from sunlight. It’s the brainchild of the National Institute of Advanced Industrial Science and Technology, Mitsubishi Corp and Tokki Corp.
According to an article at TechOn, “The organic thin-film solar cell consists of a plastic substrate, phthalocyanine layer, fullerene layer and so forth.”
No word on how much power it actually generates, but it would be fantastic to replace all your houseplants with these.
Californians will soon bask in the glow of 245 megawatts of green solar power, thanks to a new deal between Southern California Edison (SCE) and eSolar. SCE will purchase power from eSolar’s pre-fab, modular solar plants, which will harness the blazing sun of the Southern California desert.
eSolar recently received a $130 million charge of funding to develop its new system, which uses mirrors to focus sunlight on a central tower. The white-hot beam heats water to steam, which spins a turbine to generate electricity. They system is modular, allowing incremental expansion to meet growing power needs. eSolar will start building the new solar power plants in 2011. The initial phase of plants will provide enough juice to power about 160,000 homes.
In March, SCE announced that it would install about 65 million square feet of solar panes on Southern Californian commercial buildings during the next five years. The solar panels should be good for approximately 250 megawatts of power, enough to power 162,000 homes, and will cost about $875 million to install.
It’ll be interesting to see how things progress as solar panels continue to become more efficient and inexpensive. I can envision a time when most homeowners will be able to afford their own panels, thus negating the need for power companies like SCE.
