I've noticed a lot of advances in solar power in the last couple of months and I thought you might be interested. There are solar panels for the roofs of cars, solar trains (sort of), and lots more below the fold.
Shops could stock rolls of solar panel posters, and cut it to meet a customer's needs. The poster could be mounted behind a window or attached to a cabinet. Britton's team has built a successful prototype and is seeking to commercialise the project.
A solar train? Well yes and no. This is from Green Car Congress:
ANSA. Italy has unveiled Europe's first solar-power-assisted train. The solar panels on the train's roof do not drive it but provide energy for its air conditioning, illumination and safety systems.
The PVTRAIN project, partly funded by the EU, has been under development since 2003, and involves 10 prototype units: 5 carriages, 3 cargo wagons and 2 locomotives. -snip-
The panels on a rail car can deliver approximately 1.36 kW of peak power. In the development and testing from July 2003 to May 2005, the solar panel system generated a total of 1,017.41 kWh.
Solatec LLC has introduced flexible, rooftop-mounted solar panels for hybrid vehicles, starting with a kit for the 2004-2006 Toyota Prius. The downside is the cost, $2,195 They've also patented an unmanned solar powered spy plane. From Yahoo Finance:
Solatec's photovoltaic kit (patents applied for) adds two flexible, conformal panels that charge the hybrid automobile's auxiliary battery through a proprietary charger/current-limiter system concealed behind interior trim panels. The self-adhesive, rooftop-mounted panels are only 0.6mm thick and cause no change in aerodynamic drag.
The cost of super-pure silicon crystals is one of the major factors in the price of solar cells. An article in September Nature Materials outlined a way to use far less expensive "dirty silicon" for solar cells. This would be a major breakthrough in affordable solar technology. Here is a summary from Science News Online:
While there had been enough pure stock for the electronics industry, the needs of the growing photovoltaic industry--which uses silicon for more than 90 percent of its solar cells--caused overall demand to exceed supply in 2004, notes Eicke R. Weber, a materials scientist at the University of California, Berkeley and the Lawrence Berkeley (Calif.) National Laboratory. This triggered a drastic price increase in pure silicon, dealing a blow to the solar cell makers.
Silicon stock that is less pure and therefore less expensive is available, says Weber. But the increased amounts of iron, copper, and other metal contaminants in these stocks reduce solar cell efficiency. Clusters of these metal atoms attract the solar cell's charge-carrying electrons, reducing the amount of current that the cell can generate.
The researchers found that silicon hosting larger but fewer numbers of clusters performed better than did samples with smaller but many more clusters. They tested this result by heating samples and then cooling them at different rates, which enabled the researchers to control the distribution of the metal. Weber's team found that silicon with micrometer-size clusters, spaced hundreds of micrometers apart, was four times as efficient as silicon with more-finely-distributed, nanosize clusters.
"Without changing the total metal content--only changing the way it is distributed--we get a drastic change in the electrical property," says Weber. "If it is possible to concentrate the metals in a few big clusters, in principle, one can make good solar cells out of dirty starting material."
Pyron Solar has developed a solar array that they say can generate power at competitive costs. The unit is 37.3% efficient. From their web site:
This revolutionary design is a low-profile floating system with short-focal-length lenses concentrating direct sunlight by 400X onto photovoltaic cells. These advanced multi-junction cells produce 800 times more electricity than conventional non-concentrating cells the same size.
The National Renewable Energy Laboratory of the U.S. Department of Energy confirmed 37.3% efficiency. -snip-
The first PYRON-SOLAR solar power plant with BOEING-SPECTROLAB photovoltaic cells has been built in El Cajon CA, near San Diego. The platform, 23 feet in diameter and just 12 inches high, generates 6.6 kW peak. The picture shows that except for the cutout areas along the perimeter, the whole surface of the platform collects sunlight. In full-sized power plants, such cutout areas amount to less than 2% of the circle.
· BOEING-Spectrolab holds the world record in efficiency of solar cells.
· PYRON-SOLAR, INC. holds the world record in lens-surface per unit ground-surface.
· The world record in the lowest solar-electricity production costs can be achieved by combining these innovations.
Yield: At 2,850 kWh/m2yr direct-sunlight as in sunny deserts, the annual electricity yield will be 450 kWh/m2year or 450 GWh per km2year.
Performance-comparison: Per unit of total land area Pyron power plants produce:
· 14.5 times more electricity than the world's largest plant SOLAR II in Dagget, CA.
· 8.6 times more electricity than the huge LUZ power plants in California.
· 189 times more electricity than the Manzanares (Spain) Solar Chimney power plant.
System Price: The extremely high efficiency and the low material requirements make the new system competitive with conventional power plants. For large Pyron power plants a calculation shows that the price for the high-tech parts including the cell and the material for the low-tech parts will be $1.87 per watt. Depending on where the units are constructed, the labor costs will vary. With manufacture in the U.S. the total cost is estimated to be around $3 per watt.
These are some startling developments that show both how solar energy may soon be affordable and how it can be used in new and innovative ways.