Thursday, February 18, 2010

Photovoltaic Nanotech: Solar Power, Cheap(er)

"Photovoltaic Breakthroughs Brighten Outlook for Cheap Solar Power"
Scientific American (February 16, 2010)

"Novel materials might make harvesting sunlight for electricity affordable"

"Enough sunlight bathes Earth's daytime half in an hour to meet all human energy needs for a year. Sadly, there are several problems with meeting human energy demands by tapping such abundant, free solar power—not least of which is the cost of making semiconducting material that can cheaply harvest the power in sunlight. But material improvements from the California Institute of Technology and IBM might just lower the cost of solar power.

"Graduate student Michael Kelzenberg and other materials scientists at Caltech employed vertical crystals of silicon—microwires, like "blades of grass," Kelzenberg says—to capture as much as 85 percent of the full spectrum of incoming sunlight, the researchers report in the February 14 Nature Materials. (Scientific American is part of Nature Publishing Group.) Their efficiency is almost as good as that of traditional silicon wafers, yet they require just one percent of the silicon in such wafers...."

I've posted about developments at IBM before ("Solar Power Technology Gets Cheaper - IBM" (May 22, 2008))

Scientific American does a pretty good job of discussing an exciting development in solar power generation. And acknowledges something that's very important: for a technology to be used, it isn't enough to be "green." It also must
  • Work
    • outside the laboratory
    • On large scales
  • Be comparatively inexpensive

"Green" - And Keeping It Real

It's like those high-efficiency light bulbs that all the relevant people were using a few years ago. I'd have used them, but my household has a limited budget - and amortized cost of the things was significantly higher than the incandescent bulbs we're still using. That, and they wouldn't fit in our lighting fixtures.

Sure, it'd be nice to buy all-new lighting fixtures for the house, spend more on "green" bulbs, and - while we're at it - build a geodesic dome over the whole house, to reduce fuel bills in the winter.

But who has that kind of money?

You Mean It has to Work?!

Don't get me wrong: I think conserving power and other resources is a good idea. My family is careful about how much water and electricity we use, and we recycle. But "green" tech has to work and be affordable - not a way for rich people to congratulate themselves on being 'concerned' and 'sustainable.'

I've put more "Related posts" on this one than I usually do - because I think that working out next-generation power generation technologies is important. So important, that I think the "green" solutions should actually work.

That's because we're quite clearly at the point where we can start developing a rational alternative to burning fossil fuels: one that doesn't involve a hippie lifestyle.

Technology, Hope, and One Tough Mother

I don't think that technology will solve all our problems, of course - but I don't believe that we'll all be dead in about a month because we're around 1,000 times over Earth's 'carrying capacity' for Homo sapiens sapiens. ("Food, Agriculture, Technology, and City Folks," Drifting at the Edge of Time and Space (October 2, 2009))

If - when - technology for converting sunlight to electricity becomes efficient and affordable enough to expand its practical applications, we'll have a comparatively clean energy source. Which is good news.

There's a down side, as usual. The first paragraph starts with: "Enough sunlight bathes Earth's daytime half in an hour to meet all human energy needs for a year...." The numbers vary a bit from one telling to another, but I've heard that claim before. And, I'm inclined to believe it.

But - think about it - if sunlight is converted to electricity before it reaches the ground: it doesn't reach the ground.

I think that's one reason that Los Angeles isn't solar powered today. A couple decades back, I took best-case numbers for high-efficiency solar energy converters, and found that all electrical power needs for Los Angeles could be filled by solar power. If they paved the Mohave Desert with solar collectors, and orbited mirrors to bathe it in full sunlight 24/7/365.

Leaving the Mohave in complete, permanent darkness. The way I see it, there wouldn't be anything left alive, after the scavengers were done.

I don't see Los Angeles leaders starting that sort of a project.

And I don't think they'll have to. One option - which is finally being seriously considered - is to put the solar collectors where they belong: in orbit. (More of that in "Related posts")

No, I don't think 'we're all gonna die' not any sooner than we would normally. And I don't think humanity is doomed by our new technology, any more than we were doomed by the impending flint crisis. Again, think about it: we were using flint for quite a few tools, not all that long ago. Eventually, we'd run out of usable flint supplies - and everybody would perish. Didn't happen, because we started using something else. (Another shameless plug: "Move the Planet - or - Safety First," Drifting at the Edge of Time and Space (December 9, 2009))

And, although I think it's a good idea not to untreated dump industrial water in water we're going to drink later - I'm not all that concerned about the 'delicate' web of life on Earth.

If Mother Nature was a person, I'd depict her more along the lines of Queen Boudicca, than Clara Bow. ("Frail, Delicate Little Mother Nature?!" (December 20, 2009))

Life on Earth is around, after maybe seven major ice ages, unnumbered asteroid and comet hits, and massive volcanic events, like the one(s) that left the Deccan Traps. The Mount St. Helens was an inconvenience, compared to things like the Yellowstone eruption, about 630,000 years back.

Mother Nature? She's a tough old mother: and can take care of herself.

The Lemming will get down from the soapbox new.

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