You might have noticed lots of buzz this past week about Michigan-based manufacturer Dow Chemical Company’s new line of solar shingles . DOW POWERHOUSE shingles are made of CIGS or thin film photovoltaics. The shingles are designed to be installed like regular shingles–and by regular roofers, which is what sets them apart from shingles currently on the market. Now, Dow has not made a lot of technical specs available about these shingles, and we at GetSolar can’t seem to get answers to some of our questions directly from them. A couple sources say they operate at about 10 percent efficiency (which is fairly standard for shingles; normal solar panels are more like 16 to 20 percent, though some lab tests have gone as high as about 30 percent). So, we can’t discuss these particular shingles in depth. What we can do is tell you some of the pros and cons of solar shingles in general.

Pros:

1. Easy to install. Even with normal solar shingles, which do require professional solar installers’ attention at some stage, some of the work can be done by regular roofers.
2. Can be cheaper than normal solar panels. This is true pretty much only when you’re replacing your roof anyhow, and the slightly higher cost of solar shingles is then offset by what you’re saving in traditional roofing materials.
3. Appealing aesthetics. Many people prefer the integrated look of solar shingles to normal solar panels. The surface is still much like the dark blue, shiny surface of regular panels, but since they’re the same size and shape and height as your other shingles, they blend much better. People with strict HOAs or in historic districts find solar shingles appealing for this reason. For my part, I actually love how normal solar panels look, and if you’re making the investment in solar, isn’t it nice to get a little green street cred by getting noticed?

Cons:

1. Less efficient. With most solar panels, you can install about 1 kw of energy generating capacity on 100 square feet of roof surface. With solar shingles, you need 30-50 percent more installation area, depending on the site in question as well as on the particular shingles and panels you’re comparing. Efficiency can be further reduced by angle: with regular solar panels, installers can adjust their angle of exposure to the sun to maximize insolation (fancy word for how much sun actually hits the panels and is transmuted into electricity). This means that you need more product to achieve the same output, so you’re spending more per watt. Which leads us to…
2. Usually more expensive. Due to the efficiency losses, most homeowners would see more expensive project quotes with solar shingles than with normal silicon solar panels.
3. Fewer installers work with them. It can be challenging to find professional solar installers who will give you a quote for solar shingles. Partly this is because the shingles require different training, which not all installers pursue, and partly because due to their lower efficiency, it can be harder for installers to present a quote that will get you a good return on your investment.

Dow’s new product won’t come to market until at least 2010 and possibly later, and until production catches up with demand, these solar shingles may be hard to get your hands on. Low efficiency solar shingles that cut solar installers out of the picture aren’t exactly a recipe for industry success, either; so while it’s a great technology breakthrough, until we know more about it, we’re reserving judgment. And hey, if you’re interested in going solar? We’ve said it before and we’ll say it again: waiting for new technology to come out and for prices to drop is not always the wisest path.

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