As part of the Mayor's Energy Challenge, City Council passed a resolution setting a goal of 5,000 Solar Roofs in Ann Arbor by 2015. The Energy Commission anticipates that many of these solar installations will be solar hot water systems, with more solar electric systems appearing as the program grows.
Solar in Michigan?
Nature runs on solar power and so can we! Contrary to popular belief, the sun in Southeast Michigan can provide a significant percentage of our community's energy needs. According to the US Department of Energy, this clean renewable resource is available to southeast Michiganders an average of 4-6 hours daily. If every residential building in Ann Arbor had a one kilowatt solar electric system on the roof, we could generate over 30 million kilowatt-hours of clean electricity each year or about 10% of the Ann Arbor's 2000 residential electrical use.
Ann Arbor compares favorably to cities implementing solar programs in other parts of the country and is sunnier than both Germany and Japan, countries that lead the world in solar energy use. More specifically, Ann Arbor's solar exposure is:
- 97% of Madison, WI
- 98% of Chicago, IL
- 80% of San Francisco, CA
- 78% of Austin, TX
- 108% of Portland, OR
Solar Hot Water
A solar hot water system is one of the most cost-effective ways to use renewable energy in Southeast Michigan. In a typical solar hot water system, panels on the roof allow the sun to heat a glycol solution that circulates through a heat exchanger in the hot water tank. The picture at right shows solar water heating panels on the roof of Fire Station #1 in downtown Ann Arbor, which were installed with the help of a $6,000 grant from the Michigan Energy Office. The Fire Station solar system is expected to provide about half of the station's hot water needs and pay for itself in about six years.
Residential systems typically cost about $6,000 and are eligible for federal tax credits. Most systems pay for themselves in 6-10 years.
Solar Electric (Photovoltaics)
Solar electric systems are not as cost-effectic as solar hot water systems yet in Southeast Michigan, with paybacks of ten years or more. Solar electric systems, however, are becoming more popular as a means for homeowners to reduce their reliance on heavily-polluting and centralized coal plants. Residential solar electric systems typically cost around $10,000 (more for systems with battery backup), not including applicable federal tax credits.
Solar Mapping
A group of University students working with the EnHouse used aerial photographs to analyze the solar potential of single-family houses in Ann Arbor. Their study concluded that 86% of 22,000 Ann Arbor rooftops would be feasible sites for solar hot water installations.