eco: solar wind photonic membrane evaporator

I wrote about having both kinds of solar panels. (Quick update: The solar heat panels do heat our domestic hot water, but our overall heating system is still a busted inefficient disaster...)

I neglected to mention our third solar system, a proven hybrid technology that takes advantage of wind power as well. Here's a picture of one end of this engineering marvel:

Unlike our other solar systems that cost many thousands of dollars, this cost about $25, and a ham-handed DIY disaster was able to install it in an hour. All the parts are available on dusty shelves at Ace Hardware: clothesline cord, two special reels, two hooks, and a nifty line tensioner. And it worked perfectly. Anyone who doesn't install one of these is throwing money away. (Update: Some people don't understand: this is a clothes line so you can dry your clothes for free without running an energy-consuming appliance.)

Despite its excellent technical features, it didn't fit in with our garden landscaping. (We still have a miniaturized version strung across our utility room.) Here's an early look at its replacement:

Two laundry tree sculptures by Kris Borchardt, in the process of installation.

eco: solar progress uphill

Harnessing solar energy economically is the great engineering challenge of our time. My partner and I are putting solar thermal and photovoltaic on our new house, but we'll spend US$ tens of thousands of dollars (after tax breaks) just to save $100 a month in in electric and heating bills. It's an emotional and spiritual decision, not an rational economic one. But if someone can drive the cost per watt or BTU so low that putting in solar becomes an easy way to Make Money Fast, the market will take over.

Energy Innovations, founded by Idealab dot-com incubator guy Bill Gross, has thought so hard about this, it's inspiring.

• They're focused on a great mission: "Our immediate goal is to reduce the payback time for a solar system so that it becomes a sensible and logical investment to electricity users around the world."
• They're focused on a great market: the billions of square feet of roofs of commercial buildings that just lie there, unused, baking in the sun.
• They're focused on cost over technology. Read their entire Innovations section, especially the "Lessons Learned". They looked at Stirling cycle engines, servo-controlled "petal" mirrors, big heliostat arrays, Fresnel lens concentrators, ... and abandoned them because they couldn't get them cheap enough in a short timeframe.
  

Yet even with all that focus, it is still so damn hard. Solar cells with reasonable efficiency cost money, so you concentrate sunlight on them with cheap mirrors, but then you have to track the sun with a mechanism that costs money. The more you concentrate, the more you can spend on exotic solar cells, but then you have more mechanical engineering. And the concentrated sunlight bakes the solar cells: you could try to capture that thermal energy but that raises cost and compexity, so you have to come up with a cooling system. The tradeoffs are everywhere.

There are other companies with big ideas: cheap PV films, PV coatings, nano-scale concentrators, etc. While these efforts that could change the fate of the Earth get a few millions in venture funding, the 2005 US energy bill gives around $6 billion dollars in tax breaks to carbon-spewing global-warming smog-creating oil, ethanol, and coal producers.

Categories: solar, house, eco, EnergyInnovations