Thursday, October 03, 2013

Efficiency, solar power enable family to achieve “zero net energy” in 1929 home

Efficiency, solar power enable family to achieve “zero net energy” in 1929 home

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Last November, Champaign resident Scott Willenbrock learned through Environmental Almanac the story of another local man and U of I faculty colleague, Phil Krein, who was installing solar panels on the roof of his garage.

For Willenbrock, a professor of physics, the timing of that segment was perfect. That’s because he was in the midst of a project to make his own family’s two-story colonial home, a conventional structure built in 1929, “zero-net-energy.” In other words, they would generate on-site as much or more energy than they would use over the course of a year.
“It’s one thing to build zero-net-energy from the ground up,” Willenbrock said to me, citing a number of local examples. In that case, he pointed out, you can take advantage of a whole range of opportunities to insulate and weather seal, and maximize the benefits of direct sunlight. The question he wanted to answer was what people who live in older houses can do?”

Willenbrock’s question was motivated by the conviction that individuals have an ethical duty to join the battle to limit global warming. And he hopes his approach to answering that question will provide a rational model for others to follow.

The most economical way to reduce fossil fuel consumption in homes is to reduce demand for heating and cooling. So Willenbrock began his zero-net-energy quest by hiring a contractor certified with Ameren’s Act-on-Energy program to evaluate the insulation and weather sealing of his home.

That evaluation turned up numerous opportunities for improvement, and Willenbrock took full advantage of all of them. According to his calculations, weatherization alone resulted in energy savings of roughly 30 percent.

Willenbrock’s zero-net-energy quest also coincided with the need to replace an aging furnace and air conditioner. He and his spouse considered the options together and decided on a geothermal system, which is by far the most efficient way to heat and cool with electricity.

The last step in this zero-net-energy quest was to add some renewably generated electricity. And that brings us back to solar panels. Previously, Willenbrock had gotten quotes from a couple of professional solar installers that discouraged him from making the investment. Reading about Phil Krein’s DIY project, however, prompted him to investigate ordering panels online and installing them himself.

He began where Krein had, on the roof of his garage. He designed a configuration to make the best use of the space available, and then worked by phone with the same Arkansas-based vendor Krein had used, to order panels. After they arrived, he installed them with help from a handyman who had done other work at the house, and hired an electrician tie them into the grid.

Willenbrock then decided to go a step further and cover the south-facing roof on his house with solar panels. Since he did not want to work on a second-floor roof, he hired a local building contractor, New Prairie Construction, to do that installation, again using panels he had ordered himself. Even with the added cost for labor, he still spent about 40% less than the quotes he had gotten to start.

I mention above that Willenbrock was motivated to pursue this project by a sense of personal responsibility for limiting global warming, and I suspect many listeners share that conviction. I do, too. The Act-on-Energy contractor is working at my house this week.


Scott Willenbrock has created a Web site that provides the full details of his home project, which you can see at:

Better still, you can visit it on Saturday, October 5, as part of the National Solar Tour day sponsored by the American Solar Energy Society. It’s at 1017 West White Street in Champaign, and it will be open from 10:00 a.m. to 4:00 p.m.

A number of other locations in east central Illinois are part of the tour, including the Brickhouses Road development in rural north Urbana—new homes that are all zero net energy—and the Geil home in Mahomet, as well as two the houses built by UI students for competition in the U.S Department of Energy’s Solar Decathlon.

You can see details about the tour on the Web at: