We humans are needy people. We want cars and nice clothes and good beer and flashy jewelry. But we only need water, food, and shelter to survive. If you live in a single family home the shelter part is probably provided by a roof with shingles. This is good news for Dow Chemical, who is about to release a solar panel that doubles as a roof shingle called the Powerhouse solar shingle (nice play on words). Time Magazine also thought this was good news as they named the Dow solar shingle as one of the best inventions of 2009.
Dow summarizes their solar shingle on their website as follows:
The Dow POWERHOUSE™ Solar Shingle delivers true building-integrated aesthetics by integrating PV functionality into an asphalt roof-shingle form factor. It utilizes high-efficiency, CIGS-based, PV cells manufactured on a flexible substrate. These cells are laminated and subsequently over-molded into the final shingle design using conventional materials and polymer processing methods. Dow's groundbreaking technology integrates low-cost thin-film photovoltaic cells into a roofing shingle design, which represents a multi-functional solar module. The innovative product design reduces installation costs because the conventional roofing shingles and solar generating shingles are installed simultaneously.
Consumer Reports has posted a great video about the Dow Solar shingle on their Facebook page. They estimate the system will cost a user $25,000 to install but they don't say how big of a system this will buy (in terms of kW) so this really doesn't help consumers make a buying decision ($25k for a 5 kW system is wonderful. $25k for a 2 kW system is lousy)!
My guess is that the Dow solar shingle is going to work best on a new home being built that doesn't yet have a roof with traditional shingles on it. This way you will only have to pay for roof shingles 1 time (as opposed to paying for traditional shingles, then paying again to replace them with solar shingles later on). Also, if you are building a house it should be oriented with the longest side facing south, which will optimize solar PV output along with keeping your home warm in the winter.
Many other blogs covering the Dow solar shingle say the advantage over a traditional roof mounted solar PV system is that the solar shingles are easier to install and they are expected to cost 10-15% less; however they conveniently leave out one vital point: The thin-film solar cells used in the shingle are made by Global Solar and are only 10% efficient. Compare this to a SunPower 225 panel, which is 18% efficient, and the solar shingles pale in comparison. You can't just factor in initial costs of the system, you also have to figure in lifetime power output which relates to how much money you will save!
Basically, if you are going to look at putting solar on your roof you are going to have to take several things into consideration when comparing traditional PV panels against solar shingles:
- aesthetics (advantage solar shingle)
- initial cost (undecided)
- ease of installation (solar shingle on new roofs, undecided on retrofit applications)
- lifetime power output (traditional PV panels with their higher efficiency)
In any case, find some professional solar installers in your area once the panels are released and get several quotes with different types of systems.
Dow has slated the shingles for a limited released in 2010 and wide release in 2011. As with many clean energy products, the solar shingles will be eligible for the 30% federal tax deduction and your state and/or utility may offer further tax credits/rebates.
Is anyone planning on installing these on their home?
Update 5/2/12 - Dow solar shingles now available in Northern CA and Central TX