by Dan Haugen
A new report from the Green Institute documents the experience of a group of “solar pioneers” in one Minneapolis neighborhood.
The Southeast Como Improvement Association recently assisted 16 homeowners with installing The solar thermal water heaters. The group called themselves “solar pioneers” and the Green Institute report’s goal is share the lessons learned with other groups who might want to make the same investment.
“We think it’s a great example of what a neighborhood or community group can do to fight global warming,” said Carl Nelson, associate director of the Green Institute.
Solar thermal systems capture the sun’s heat the same way a garden hose does on a hot summer day. A coil of dark tubes sits in a box on the roof. A liquid inside absorbs heat, and a pump then circulates the solution to another set of coils inside a water tank, where it radiates into the water.
They’re more economical than solar electric panels, and Minnesota gets enough sun for a typical system to provide between 50 percent and 80 percent of an average home’s annual hot water needs, according to the Green Institute report.
Still, there are plenty of hurdles casting a shadow on residential solar projects, the case study notes. High prices, a lack of state incentives, and complicated regulations hinder efforts like the Southeast Como project, it says.
“I was frustrated with how slow things have been moving on the renewable energy front. I just kept thinking: What can we do on a local level?” said Justin Eibenholzl, environmental coordinator for the neighborhood association.
Eibenholzl started planning the project a couple years ago after convincing Innovative Power Systems, a major solar installer that’s based in the the neighborhood, to offer a discount if he could round up at least 20 customers who were interested in buying the systems.
The interest exceeded that goal. A total of 39 people signed up expressing interest in buying a system through the neighborhood group. Only 20 ventually paid a half-down deposit to allow the program to move forward.
Innovative Power Systems sold each system for $6,000, about $1,500 less than what they were retailing for at the time. (Copper prices have since driven up the cost of the systems; the tubing inside is made of copper).
Several participants ran into unexpected costs of $2,000 or more related to engineering studies and structural improvements before the systems could be installed. The panels weigh about 300 pounds each, but when positioned upright they catch the wind and can add stress to a rooftop.
City permits also contributed to higher costs, the report notes. Each homeowner needed a $165 general construction permit and a $65 plumbing permit. The Green Institute suggested a more streamlined permit system would help expedite the process of installing them.
It also recommends that the state offer a solar thermal incentive, similar to the rebate available for solar electric projects. The financial return on solar thermal systems can be better than electric panels, but it still takes between 13 and 40 years to recoup costs, it says.
“We have decent solar resources, but there aren’t a lot of financial resources,” Eibenholzl said.
Once the systems are installed, though, there is little maintenance involved. They last more than 30 years. The pump that re-circulates the liquid usually needs replacing every 10 or 15 years at a cost of about $100 to $300. The antifreeze solution inside needs changing every 3 to 5 years.
Eibenholzl said it’s not been decided yet whether the neighborhood will attempt a second phase of its solar pioneers program. Nelson, meanwhile, said he’s confident that as the market for solar projects grows, many of the issues Southeast Como residents encountered will be resolved, and that projects like theirs will be more common in the years to come.
Green Institute: Solar Pioneers: A Case Study of the Southeast Como Neighborhood Solar Thermal Project (PDF)
Minnesota Daily: Some residents getting hot water via solar power