100 km sq. How big would ANWR be? I guess
“pristine wilderness” can be covered if the energy produced is of the “correct” sort.
Isn’t anyone going to stand up for the gila monsters and the tarantulas, who need sun to survive?
Engineers create bone that blends into tendons
FReepmail me if you want on or off my health and science ping list.
For the renewable energy ping list
A 100km2 area covered with 10% efficient solar cells can produce enough electricity to satisfy the national requirement.Hang on... assuming the grid to support such a vast network of technology could be flawless (and leaving aside the arguments against covering an appropriately sunny region with photovoltaic arrays of any type 62 miles on a side), these critters have a DC output, meaning that an even larger array has to be constructed to handle the conversion losses to feed the national AC grid (and give or take conversion from there to jump the voltage). Add to that the additional capacity needed during shunts (shunting would be a necessity during malfunctions, which could be due to wind, gee, ya think? Or lightning strikes, decline in efficiency of individual cells, plane crashes, debris from space, manufacturing flaws, installation mistakes, TERRORIST ATTACK, etc), plus growth in demand...
'Denim' solar panels to clothe future buildingsUnlike conventional solar cells, the new, cheap material has no rigid silicon base. Instead, it is made of thousands of inexpensive silicon beads sandwiched between two thin layers of aluminium foil and sealed on both sides with plastic. Each bead functions as a tiny solar cell, absorbing sunlight and converting it into electricity. The aluminium sheets give the material physical strength and act as electrical contacts... The bumpy surface presented by the spheres offers a large area for absorbing light, giving the material an overall efficiency of 11 per cent. This is comparable to the performance of conventional photovoltaic cells, and much better than proposed flexible designs based on conducting polymers.
by Jenny Hogan
15:30 15 February 03Solar cells aiming for full spectrum efficiencyToday's best cells have layers of two different semiconductors stacked together to absorb light at different energies but they still only manage to use 30 per cent of the Sun's energy. Theorists have calculated which two bandgaps would give a maximum efficiency of 50 per cent, but until now they have not had the semiconductors to do the job. Now Wladek Walukiewicz and his team at the Lawrence Berkeley National Laboratory in California have found a material that fits the bill - a semiconductor called indium gallium nitride (InGaN)... There is one catch. Scientists had previously overlooked InGaN because its bandgap range was thought to be much smaller - data books quote the lower limit to be twice as high as Walukiewicz claims. The difference may be due to the purity of the semiconductor. The samples Walukiewicz tested were made using a painstaking, and prohibitively expensive, method to grow very pure crystals of InGaN one atomic layer at a time. The team now hopes to collaborate with the National Renewable Energy Laboratory in Colorado to try to build cheap InGaN solar cells.
by Jenny Hogan
10:15 08 December 02SunPower AnnouncesBased on a unique rear-contact design -- which maximizes the working cell area, hides unsightly wires and makes automated production easier -- the A-300 achieves over 20 percent efficiency compared with currently available cells in the 12% - 15% range. The National Renewable Energy Laboratory (NREL) has verified 20.4 percent conversion efficiency for the A-300... [T]he A-300 silicon solar cell delivers 3-kW in less than 17 square meters, allowing SunPower's customers to trump the world's best area-efficient construction designs... The A-300 cells eliminate front-side metallization by utilizing a patented rear-contact design to provide more cosmetic uniformity and maximize energy generation.
World's Most Efficient,
Low-Cost Silicon Solar Cell
by Bobby Ram & Agnes Toan
May 12, 2003