It’s good to see important technology finally make it to (hopefully mainstream) market. The idea of having solar arrays manufactured into building materials such as roofing shingles is not new. However, the point is that whatever the technical history, having the technology brought to market in a big way is almost the final step in having a significant impact. (The final step being common use.) A lot of promising technology never makes it to widespread distribution. So it is significant when a major company, in this case Dow Chemical (USA), is committed to manufacturing and distributing solar shingles, even though there are questions about the commercial realities.
Dow is not alone with integrating solar-cell technology into building materials. Among others, Suntech Power (China), the giant of solar technology, has already brought integrated products to market, although it appears to be backing away at the moment in favor of manufacturing dedicated solar panels. The key difference for Dow is that Suntech uses crystalline silicon photovoltaic cells, the most common approach, while Dow is using what is called CIGS (copper, indium, gallium, selenium) thin-film technology. According to reports, CIGS is cheaper to manufacture than crystalline silicon and somewhat more efficient.
The difficult part of integrating solar (anything) with common building materials is that it must: 1. Be acceptable as building material, 2. Produce a practical amount of energy, and 3. Not cost too much. The integrated solar shingle will always be in competition with regular shingles plus a mounted solar panel. The main difference will be that integrated shingles are not obtrusive. How much are people willing to pay for aesthetics? Sometimes quite a lot, but not if it’s desirable to have widespread use of the technology.
The questions about Dow’s shingles will hover around price (the price hasn’t been set), ease of installation (the promotions say it does not require expert installation except for electrical hookup), and the long-term durability (Dow is using technology from Global Solar, which encapsulates five solar-cells per shingle set in strings surrounded by a glass and polymer coating). The product is expected to be distributed by fall of 2010.
One more detail: The Dow production is being subsidized by the U.S. government to the tune of $18.7 million in tax credits. This is usually good news, bad news. The good news would be that Dow’s approach is sound and worthy of government backing; the bad news could be that the technology is marginal and only worth attempting if the government ponies-up the money to get it started.