Is anyone making greenhouses out of photovoltaic glass?

Chinese solar energy company Suntech has developed a transparent photovoltaic glazing where windows are able to function as solar panels. This would seem to offer a tremendous advantage over traditional solar modules that are bulkier, less aesthetically pleasing, and most importantly for anyone intending to grow a garden under them, not so good for letting the sun shine through.

I’m imagining one of these in my backyard. Hello, fresh tomatoes in February! Sure, I can do the year-round gardening thing with a traditional greenhouse, but I’m still going to have to have an external power source to operate lighting, heating, pumps, and other accessories. Which in most cases would mean wiring the greenhouse from an extra line run from the house or somehow connected to the grid.

But wouldn’t a greenhouse built using the photovoltaic glass be practically self-sufficient in terms of its energy needs? Not only would it provide the usual greenhouse function of being a heat trapping, closed environment, but it would also generate the electricity necessary to run its accessories. Such needs might not be very large for smaller units (like my hypothetical backyard tomato operation), but in larger commercial contexts that require extensive climate control, irrigation, automation etc., the payback could be considerable. Unlike normal solar panels that are installed in blocks on top of existing surfaces, the PV glass is the surface. You have to enclose your building with some sort of material anyway; why not use a material that pays for itself?

Just off the top of my head, a PV glass greenhouse would seem to offer a number of benefits:

• The entire surface area can collect sunlight.
• The greenhouse can generate its own power for heating, lighting, pumps, etc.
• Excess capacity can be used for household energy needs, or sold back to the grid.

I’ve done (some) searching online, and can’t seem to find anything like this. It seems to me that something would have turned up. Is there something I’m missing? Is there a technical roadblock? Prohibitive costs? Or did I just search in the wrong places?

UPDATE, Tuesday, Jan. 13- Looks like my “kiss of death” that applies when I buy a stock that tanks immediately thereafter applies to blog posting, too: Suntech just laid off 10% of it’s workforce. I apologize.

Image: “Empty Greenhouse” by lostajy on Flickr.