Sunday, May 15, 2011
Solar Power Needs to Grow Up or Give Up
When I was young, in the late 1980s, the world was highly optimistic about the future of solar power. There were propositions of solar cells on roofs and cars running on sunlight during the day. I was certain that by age thirty I would be living in a totally futuristic sun-fueled world.
Yesterday I wrote a satire piece about Solar Impulse flying its first successful international flight. While this was a great feat of engineering and a landmark acheivement, the article intended to point out how far away from useful the technology is. It's been 25 years since the promise from my childhood of a solar future, and we're still barely acheiving a 25 MPH average for flight powered by this method.
However, the main point of the flight was that the plane used no combustible fuel, for an equivalent average of infinity MPG. Hardly inefficient!
Solar cells on the rooves of houses would have been one of the greatest, most useful parts of our modern world. Above all other electrical consumptions in our houses, air conditioning is the number one waster of energy. With solar panels, we'd be generating electricity for our own air conditioning during the day, when we most need to use it. These panels would effectively end rolling blackouts and lower electrical costs in households.
Unfortunately, the cost of producing solar cells is still very expensive, leading to a high pricetag on the units themselves, so installing them is not financially possible for most people. Even with the promise of greatly reduced electrical bills and the possibility of selling extra energy back to the utility, most people are unwilling to front the cost for these things. They must be cleaned; dirt/soot and bird crap can collect on them and reduce their effectiveness. They are easily damaged by hail. Possibly most seriously, they're a big target for theft since they're merely attached to the outside of your house.
The typical solar cell reaches equal efficiency to fossil fuel after 5-7 years of use, so getting beyond that hump is the key. This means that you must use them for this length of time for the price of installation and maintenance of the panels to equal the amount you've saved by not using electricity generated by a coal-burning power plant. If you've managed to keep the panels clean, avoided having them destroyed by hail, and no one climbed up onto your roof to rip them off, then you're in the clear. Good job! Oh, except that they become less efficient after ten years, and have a maximum lifespan of about 30-35 years.
As for those cool-looking sun-powered cars we saw driving through the desert in stylized educational videos twenty years ago, no one's driving them. It's clearly not a viable option. Thought your rims were expensive and easy to steal? See what happens when you park a giganto solar cell in a parking garage. We can't even pull off all-electric vehicles yet, despite their existence since the 1890s.
As for your choices for types of solar panels, there are two different generations: The first has high efficiency, but high cost; the second has low efficiency and low cost. A third generation of solar panels is currently in development and is expected to marry high efficiency with low cost, though not even a proof-of-concept prototype has been successfully created yet. The earliest estimate for mass production of these cells is 2020, so don't expect to be going off-the-grid anytime soon.
My day-to-day interaction with solar panels has been limited to road signs and trash cans. Yes, trash cans, like this one that I encountered at a public beach in Maine:
Don't ask me what that's for, but at least it's not an ineffecient coal-burning trash can. So is there a public future for solar power? Yes, but not in mass-production power farms in the desert, and not as a means for powering personal transportation. It'll be all about small devices. The sidewalk lights I bought my mom for Christmas are a good example. They charge throughout the day and stay lit for most of the night. They don't power a server room, or a thousand pounds of metal. Small solar-powered devices will have basic, fundamental purposes. Until a new generation of panels appears, we'll just have to keep burning things to spin turbines with steam. Follow @torqtorq
Posted by torq at 4:05 PM