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.

Well, I believe it has a lot to do with the price of just about everything, both now and increasingly so in the future. Any modern economic activity requires a certain energy expenditure. Making a widget requires electricity for the widget factory. Extracting raw materials for the widget requires energy for exploration, mining, and refining. Transporting the widget of course requires fuel for your truck fleet, cargo shipping, etc. And so on down the line.

As the finite supply of non-renewable energy sources goes down and the cost goes up, so does the cost of everything that requires energy. Which amounts to basically everything that makes up modern civilization as we know it. Eventually these costs increase to the point where they become a drag on economic growth.

Since our economic system is fundamentally predicated on perpetual growth, growth is therefore a good thing to those of us that value things like jobs, projects, a stable society, and plenty of other things that we tend to take for granted.

Basically, it seems that something’s gotta give: Either we come up with renewable and sustainable sources of energy to fuel our growth-based economic system, or we scrap the growth-based system and replace it with some form of steady-state economics.

Unfortunately, all that adopting a steady-state system will do is delay the inevitable – non-renewables will simply run out later, rather than sooner.

Which is why I feel strongly about this topic, and feel that it rates a place among the top-level categories here.