Geothermal system means no oil or gas bills for winter heating

From the Duluth News Tribune, Duluth, MN

By John Myers

At a time of year when most of us cringe at the thought of writing big checks for home heating bills, forgive Harold Hanson for smiling.

Hanson and his wife, Julie, installed a new furnace and air conditioning system last week that will keep their modest 1950s ranch in Duluth’s Fond du Lac neighborhood warm without burning an ounce of fuel oil, propane or natural gas.

Like a growing number of Northlanders, they’ve turned to a ground source heat pump and geothermal energy to heat and cool their home. The same system also preheats the water going into his electric water heater for dishes and showers.

“We knew we had to replace our old oil heat system, and we were looking around for options,” said Hanson, a retired Duluth, Winnipeg and Pacific Railway clerk. “At first this seemed too expensive. But, when you throw in the rebates and tax incentives, and the fact we’ll never have to buy oil or gas again, it really makes sense for us.”

Hanson has a bit of a green side as well, and he’s happy to stop burning fossil fuel to heat his home.

The U.S. Department of Energy says 40 percent of all carbon dioxide emissions in the nation come from burning gas, coal and oil to heat and cool homes and buildings. Heat-pump systems

already in place are cutting more than 3 million tons of carbon dioxide each year, the equivalent of taking 650,000 cars and trucks off the road.

If the term geothermal conjures images of bubbling hot springs in Iceland, that’s only half right. In the Northland, geothermal heat in the ground actually comes from the sun and is stored below the surface in the ground or water.

Hanson’s system uses water from an old well on his lot that’s at a nearly constant 45 degrees as the source of heat energy. While the science is hard to explain, the heat pump transfers energy from that 45-degree water and converts it into 130-degree hot air to heat the house. In the summer, the same system can create cold air to cool the home.

The basement unit is about the same size as a traditional furnace.

In Hanson’s open loop system, after the well water is run over coils of antifreeze, the water, about four gallons per minute while it’s operating, is discharged back into the ground to percolate through a gravel field. Closed loop systems use a finite amount of fluid running through large coil systems buried to absorb warmth in the ground. Closed loop systems, buried about 8 feet under the surface, generally require a footprint about twice the size as the main floor of the building, so a larger lot is required.

“This (open loop) type of system was more attractive for us because we didn’t have to tear up the entire yard,” Hanson said.

Hanson’s system, including work to expand his well’s capacity and install a new electric service board in his home, will cost about $20,000. But rebates from Minnesota Power and the state of Minnesota, along with a 30 percent credit for the system off his federal income taxes, will bring the price way down.

And Hanson will never need to write another check for gas or oil again.

“The payback is generally about five years compared to a heating oil system or propane, maybe a little more, eight years, for a natural gas system,” said Jeff Aili, estimator and project manager for Summit Mechanical Systems of Duluth that installed Hanson’s system. “Think of it as an investment, and the rate of return is about 20 percent per year. How’s your IRA compare to that?”

For Hanson, the new system will eliminate last year’s $1,700 fuel oil bill and trim heating costs to about $550 for this winter, all for electricity. Heat pumps generally use more electricity than traditional systems, although the water-heating savings often help make up that difference.

Moreover, Hanson’s system will provide cheap central air conditioning in the summer. By a quirk of physical science, many systems actually use less energy in the summer if they are producing cold air for air conditioning, Aili said.

Summit — one of several companies in Duluth that install geothermal systems — is in the process of installing ground source heat pumps at several new homes across the region, as well as at major projects like the new Mont du Lac chalet. Local builders say about half of new homes are being built with heat pumps.

Summit also installed a new heat pump system that heats water for the outdoor swimming pool and hot tub at Bluefin Bay Resort in Tofte. That system uses heat from the resort’s wastewater system to supply heat for the pool and hot tub. It also helps melt snow and supply heat for the building.

The new system cut Bluefin’s energy cost for the pool and hot tub complex from $28,000 annually to about $8,000, Aili noted.

In some areas of the Northland, geothermal systems also qualify for reduced “dual fuel” electric rates, Aili noted, saving homeowners even more.

Dave Gunderson of Duluth installed a ground source heat pump at his Lake Vermilion lake home two years ago. He liked it so much he recently installed a new geothermal system as part of a remodeling job on his home on Skyline Parkway.

“I knew absolutely nothing about it. I thought geothermal was getting heat from the earth’s crust or something,” Gunderson said.

In the first winter alone, the new system eliminated a $3,500 propane bill for the Vermilion property. Even after an increased electric bill to run the heat pump, Gunderson said he saved $2,500.

“That takes the payback from about nine years down to about three years,” he said. “With the numbers we’re seeing, I can’t believe anyone wouldn’t do this.”

Because it comes out at a lower temperature, the system runs more constant and more evenly disperses heat across all areas of the home, Gunderson said.

“We have a big vaulted room that was always cold while our bedrooms were boiling,” he said. “Now, it’s even across the whole house.”