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Swiss Federal Lab Claims New World Record For Solar Cell Efficiency
Zothecula writes "Scientists based at Empa, the Swiss Federal Laboratories for Materials Science and Technology, have set a new efficiency record for thin-film copper indium gallium (di)selenid (or CIGS) based solar cells on flexible polymer foils, reaching an efficiency of 20.4 percent. This is an increase from a previous record of 18.7 percent set by the team back in 2011."
I calculated that my daily commute would requite 3 kWp of panels if the end-to-end efficiency was 75% - which is what Tesla claims for the Model S. 3 kW of panels is 12 panels. That easily fits on my garage roof. This isn't as insane as it sounds.
If you actually sit down and DO the math, even if you covered the US with solar panels you cannot cover US yearly electrical requirements.
Assuming your numbers are correct, lets say our solar radiation conditions are 10% of the best case. Then to provide all the electricity the U.S. needs, we'd have to cover 1.3333% of the total surface area.
Of course, we can choose the best available locations for each additional panel, so we can do a whole lot better than 10% of the best case. If we can only do half as well on average, the number comes down to .267%. And we can use at least some surfaces for their original use and for solar energy production (rooftop panels).
There are lots of difficulties between here and full solar power. I doubt we'd ever want all our electricity coming from solar power. And even .267% of the surface area of the U.S. is an enormous amount, and acquiring rights to that land would probably be impractical. But if we did need to do it, space wouldn't become the limiting factor for a long time. And if we could solve all of the other logistical problems--storage, distribution, manufacture, maintenance--we would have enough surface area to provide for the U.S.'s energy needs via solar. It just wouldn't be the best way to go about providing electricity.