Swiss Federal Lab Claims New World Record For Solar Cell Efficiency 177
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."
Re:Crap (Score:5, Interesting)
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.
Re:Crap (Score:3, Interesting)
Are you mentally handicapped?
You could either store the power in batteries or sell it to the grid and buy back power later when you need it. If you are not suffering some sort of mental deficiency that should have been as obvious as the car not being the ideal place to put the solar cells.
Re:Crap (Score:5, Interesting)
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.
Re:Crap (Score:4, Interesting)
I saw an interesting comparison made by a professor: If you covered the entire area that was evacuated because of the Fukushima incident with solar cells, they would produce less power than the nuclear reactor did (not to mention how much more it would cost).
Re:Crap (Score:4, Interesting)
Eventually you have to buy more power plants too.
25 years is the normal estimated panel life, but I know of panels from the 80s that still work.
Re:recharging the Solar car at work (Score:4, Interesting)
Do the math on a solar powered car.....
Assume you could cover the entire top surface(s) of a small car with solar panels and let them charge batteries all day while the car is parked at work. Assume battery charging is 100% efficient: Panel Area ~4 m^2 (liberal, but I'm trying to make a point) Panel Efficiency 20.4% Time in sun 8 hours Sun angle derate 50% Solar input ~1kw/m^2
Then the batteries get charged with 1*4*8*0.5*0.204 ==> ~3.26 KWH A small car engine is rated at ~200 KW (i.e. Ford Focus Spec at 223 KW) If you average using only 1/4 the available power ===> 50 KW The saved energy in the battery will move you for 60min*3.26/50 ===> ~4 minutes
So, you run out of juice about the time you hit the on-ramp of the freeway.
The point being, this isn't going to work unless you have more efficient cells, more efficient vehicles, more solar panel area, or a combination of all three.
Actually the Nissan Leaf gets about 4.5 miles per KWH. [youtube.com] So if the panels on the car really can generate 3.26 KWH in only 8 hours that's 4.5 miles * 3.26 KWH = 14.67 miles just on solar power. That's pretty significant IMHO, that would be worth adding solar panels to the car, even if you have a place to park and charge it at night. For example, let's say your daily commute is 25 miles, that's 175 miles a week. For the sake of simplicity let's say the Leaf gets 87.5 miles per charge, so the user would charge twice a week in this example. If the solar panels generate a 14.67 mile range every day, that's only 10.33 miles being used by batteries instead of the full 25 miles, so instead of charging twice a week, user would charge every 8 days. This is huge, especially for people that live in apartments or other situations where plugging your car in is not convenient, they could bring the car somewhere once every 8 days for a full charging.
Re:Crap (Score:4, Interesting)
This is key. Unless your surface area is limited (space craft, vehicles), it's not efficiency that matters, but cost per watt of capacity.
Make solar cheaper per watt than coal plants (we're getting close now), and then watch all the rooftops in the country get covered with solar panels.
Even if all the rooftops combined aren't enough to produce *all* our needs, every 300MW of solar power is one coal plant shut down, and 2400 tons less CO2 produced. Per day.