Slashdot Mirror
(Solar) Power to the Masses
D3 writes "This report on a solar power tower (pdf) looks extremely interesting. Maybe one day we can have international power lines where all the countries with lots of sunshine provide power to the rest of the world? How cool would that be?" The NY Times has a good article on solar power in Japan.
then more power to 'em!
Maybe one day we can have international power lines where all the countries with lots of sunshine provide power to the rest of the world?
Great idea, but power simply can't be distributed over that great a distance.
To make up for losses due to resistance in wires, they up the voltage to absurd levels -- decreasing the current level, and, in the process, the voltage drop over a long distance. However, this can only be taken so far, and towers supplying electricity to the rest of the planet is way too far.
In fact, I'm pretty sure that the continental US is too wide for coast-to-coast power sharing (that is, power generated in, say, New York, can only be "shipped" as far west as Indiana, or so).
On the other hand, replace today's wires with some kind of high-current, high-temperature superconductor, and you're golden.
...the US would takeover those sunny countries.
Will the sunshine nations (OSEC) collude to create artificial shortages and drive up prices in the sunless nations. Rolling blackouts, $700 power bills. The best part will be when they say its the fault of the sunless nations for having draconian environmental laws.
I'm really not this bitter in person.
"The plural of anecdote is not data." -- Roger Brinner
Solar insolation is about 1kW/m^2.. Well, except for the earths rotation. Assuming a non-tracking system, we have to divide by a factor of pi, so thats 300 W/m^2.. Well, except that the average efficiency of solar cells is under 15%, so thats 45W/m^2. Now, the average home has what? 2 people in it, and the per-capita electrical usage, averaged over the course of a year is 1kW. So, you need 2kW for that home, and only get 45W/m^2. So, you need 50 square meters of solar cell, correctly angled south. And this is the best case.
Now account for clouds and dirty cells. Unless you clean the cells every few days and pressure wash them biweekly, better increase the square meters of solar cells another 50%. So, thats 60-80 square meters of cell/house..
Now the next question. Where do you store all the energy you'll use at night? If you don't store it, where does it come from? Fancy burying a few ton flywheel in your backyard? How about aa closet filled with lead and sulpheric acid batteries? If you're going to use hydrogen to store it, better double or triple the square meters of solar cell for those inefficiencies.
The same problem applies to 'Solar 2'. You need about 1000 of them to equal the average energy of a nuclear power plant. And another 299000 to equal the mean energy used by the US. To replace all energy used in the US requires about a million Solar 2's.