Solar Cell Achieves 40% Efficiency

Fysiks Wurks found on the U.S. Department of Energy website news of a breakthrough in solar energy efficiency. From the article: "...with DOE funding, a concentrator solar cell produced by Boeing-Spectrolab has recently achieved a world-record conversion efficiency of 40.7 percent, establishing a new milestone in sunlight-to-electricity performance." A page linked from Wikipedia's article on solar energy calculates the land area that would need to be covered by solar collectors at 8% efficiency to meet the world's energy needs (using 2003 figures). At 40% efficiency, it looks like a square 265 miles on a side in the American southwest would do it.

Comments

transport losses?

[toQDuj]

yes, a few hundred miles in the american southwest would do it (anyone objecting to using Texas?), but only if the entire world lived in the american southwest. As it is, energy losses due to transportation are quite significant and hinder an all-out world power source plan.

B.

Re:transport losses?

[jtorkbob]

Hydrogen conversion has its own inefficiency, so that's out.

That statistic is simply an illustration in any case. Obviously there are some other places in the world where such installations could be put; perhaps some less sunny ones would require more space to reach equivalent capacity.

In any case, I think that a 100% solar earth is unlikely:

* Much of the time it is night, and storing that much juice in batteries is impractical. Things like hydroelectric storage and thermal solar plants could help with this problem, but its a whole different research issue.
* In the event of, say, a major volcanic eruption or meteor impact, world power production would plummet. That could be the least of our worries.

Solar and wind are like the icing on the clean power cake. They are great for the role they serve, but you can't have them for dinner without getting a stomach ache.

Re:transport losses?

[Eivind]

Sure. That's actually another *advantage* of solar.

It's a lot more practical to scatter a large numer of smaller solar-plants around than it is to do the same with nuclear, oil or coal-powered plants.

If you do this, for example, by installing them on the roofs of homes you get 2 extra benefits:

• It makes the house less hot. If 40% of the sun is converted to electricity, then that's 40% which is *not* converted to heat. Decreases the demand for AC.
• It produces the most power precisely on the days when the demands on the grid is at its peak. (assuming warm/sunny areas) Which, is optimal if your goal is reducing the strain on the grid.

Re:transport losses?

[indifferent children]

Is energy really expensive enough to justify covering your house in solar cells?

Energy as we collect it now, has some non-obvious costs. What does pollution from burning fossil fuels cost us in terms of healthcare? What will sea-level rise cost us? (hint: NYC, LA, DC, Miami, New Orleans, Mobile, and others are very close to sea level, and those are just the US examples.) Would we really have spent $300B and 2,906 American lives (so far) in Iraq if we didn't need to "stabilize" the region that supplies most of our oil?

Part of every dollar that you pay in taxes, at the store, at the hospital, in fact pretty much everywhere, is an energy cost.

God, geeks are so incredibly stupid

[Anonymous Coward]

1. Deserts are not empty. They have an ecosystem.

2. There is no reason at all to fill a desert with solar cells, and then transport the energy across to the other side of the planet. Solar cells are installed locally, like on your roof, or in your back yard, on every roof across the planet. Most of the electricity consumed would be as Direct Current right from your rooftop, with an inverter converting for those appliances you still insist on retaining that us AC.

3. For dense city sitatuions with high rises who's energy needs can not be met by rooftops, etc., electricity can be sent via conventional AC lines across the conventional power grid from say no more than 50 miles away. Not the other side of the world.

4. Those who produce an excess of electricity beyond their need, sell it into the grid.