Solar energy should heat up in the Twin Cities


When presented with the opportunity, people are making the choice for cleaner energy, more efficient vehicles, etc. The Southeast Como Solar Pilot Project was one such opportunity that, based on the response (I’m still getting calls now about it), is desperately in demand.

Starting in 2005, the Southeast Como Improvement Association (SECIA) helped to launch a pilot solar project in the Twin Cities. SECIA helped the applicants and city officials find their way through a maze of applications, permits and inspections. By negotiating a bulk purchase, SECIA kept prices down. A dozen Minneapolis residents recently celebrated completion of the process. Five St. Paul installations are complete, including a larger apartment building installation.

The system utilizes two solar flat plate collectors typically mounted on the rooftop with a south facing orientation. The collectors are tilted to maximize energy gain throughout the year (45-55 degrees). The system needs a minimum of 4 hours of strong sunlight a day but this can be morning, midday or afternoon. The collectors contain propylene glycol (antifreeze), which is pumped through piping and warmed by sunshine. This loop goes through a pre-heater tank, which exchanges the energy from the collector loop with the water that the house or businesses uses. Water from the pre-heater flows into the domestic hot water heater. This turns the existing water heater into a back-up system.

The City of Minneapolis required a structural engineer to sign off on the installation design and work completed. This cost most people in Minneapolis between $400-800 just for the engineering consult and the work to beef up the rooftops cost anywhere from a couple hundred to a couple thousand–depending on if the home owners did the work themselves, age of structure, etc. Many homeowners found it advantageous to have the updates done as part of other construction, which cut the cost of rooftop work to just the cost of the hurricane ties.

The participants oriented their panels in a different way turning them sideways for most of the St. Paul installations. The owner of Innovative Power Systems lives in St. Paul and had a good relationship with inspections there and was able to learn from what happened here in Minneapolis and save those people some major headaches and some expense.

The 12 homeowners who participated in Minneapolis met recently and had nothing but good things to say, as they are turning sunshine today into hot water for tomorrow. One participant shared the story of how when it was minus 20 in January the water in the tank was at 110 degrees. Compare that to the 40 degrees it was coming into my house and it’s pretty clear who’s saving the money.

I hope the city government learned as much as the participants and SECIA did in going through this process. Environmental priorities always seem to get a lot of talk when the heat is on, but seem to fall about 12th on the list as they have for the last two decades. I hope we can help the city government see the importance of taking a more active role when it comes to renewable energy and environment. It is equally important to recognize the challenges with retrofitting existing structures, which are primarily what we have in Minneapolis and St. Paul. Developers have demonstrated they are not ready to build structures with solar panels, green roofs, or energy efficiency in mind unless they can make a buck. This is changing, but slower that it should be. There is opportunity for the government to play a role in policy here also–a duty whose shirking days are coming quickly to a close.

There’s still a federal tax credit which applies to solar thermal systems which is 30% of the system rebated up to $2000 for residential installations (uncapped for businesses). So the time to do these upgrades is now. Unfortunately, there are no incentives locally for thermal, except that you won’t pay any state tax on the solar thermal equipment.

I’ve given you a look at the tip of the iceberg, there’s a lot more to it if people want to know. I haven’t even exposed all the benefits, the CO2 reductions, the joy of creating 180-degree water from the sun–never running out of hot water, washing your clothes in hot or warm for “free.” Heating hot water with the sun’s energy is nothing new as all of us know who swim in the lakes or dip our feet in the kiddie pool.

The conversion rate is much higher too for solar thermal vs electric (30% vs 3-15%).

If only thirty years ago we would have finished what was started during that energy crisis, we wouldn’t be in the truly dire straights we are now, with our energy decisions here in Minneapolis contributing to a whole string of geo-political unrest spanning this continent and around the globe.

The Mississippi River used to power this mill town with everything from the grindstones at the Pillsbury A mill to eventually the electric lights of downtown. In 1911 the power companies saw the demand for power and built with hand tools and horse-drawn equipment the Riverside power plant fired with coal. That plant is now the oldest in Xcel’s system and generates power in much the same way it did almost a century ago, but burning four times the coal it did in 1960. About three million tons of carbon dioxide come out of that plant along with all the other nasties, like lead, mercury, dioxin, particulate matter.

If we only knew now what we know now, maybe we would we take some action.

Justin Eibenholzl is the environmental coordinator for the Southeast Como Improvement Association.