This past Friday the “Energy/Waste” research group took a trek over to Menomonie, WI (approx. 75 miles from Minneapolis) to tour Bubbling Springs Solar. This company manufactures flat-plate liquid thermal solar collectors for heating domestic water. This company does its best to obtain all of its materials locally or within the closest place possible. Bubbling Springs gets most of its materials from the Midwest, Canada, and only one screw from China. Then, they manufacture and assemble the solar thermal panels in Menomonie, WI (currently a two-man operation). The production of the solar thermal collectors has taken a toll with the turn of the economy resulting in an operation down to two people, however, new promising contracts are expected to bring up business.
The owners, Mike and Luisa, started out on their journey of making solar thermal panels back in 2003. They had old 1970′s solar thermal collectors on the roof of their farmhouse. As they began to deteriorate, Mike would take them apart to fix them. In the meantime, he realized how simply put together they were and thought that he could design a better solar thermal collector. As the story goes, they moved their operations from their farm (Bubbling Springs) to an incubator at UW-Stout, and now recently within the past year have moved to their own office/warehouse in a technology park.
Meeting with Mike and Luisa, I learned that solar thermal collectors are a simple technology that is highly efficient compared to other forms of technology such as photovoltaic panels. According to Mike, PV panels (collects sunlight and converts into electricity) are only 15-25% efficient whereas solar thermal panels are 70-90% efficient. This is because the sun naturally makes things hot as opposed to the PV panel which needs a converter to turn collected sunlight into energy/electricity. In addition to this, we were taught how a solar thermal panel was constructed together, the materials it was made out of, and how it works (we’ll go over this part in our presentation). We were additionally filled in with serveral facts and statistics – even about other systems such as geothermal systems and PV panels. We were told the best way to install a solar thermal water heating system was with new construction because then the house and plumbing wouldn’t need any retrofitting (it would already be designed in). The rule of thumb is the average person uses 20 gallons of hot water/day resulting in one 4′ x 8′ solar thermal panel per person. This means a family of four would use 80 gallons of hot water resulting in 4 solar panels. Overall, the trip and tour were very informative and very much enjoyed. Mike and Luisa were incredibly interested in our project and would love to become involved with something like the 100-mile house or the solar decatholon. The idea of “local” and “sustainable” are what they are all about.