Drilling Deep: Geothermal Heat

Many alternative energy sources have an associated mental image -- fields of windmills sprouting like flowers in a field come to mind -- but what does your brain conjure up when confronted with the term geothermal?

Even if you know what geothermal is, you might have some trouble picturing it. Which makes sense because geothermal's magic happens below the earth's surface. Chances are a home or business you are familiar with already takes advantage of this not-new-at-all technology to heat and cool their premises while spending up to 70% less on their utility bill.

Is your interest piqued?

How it works

A very simple explanation of geothermal systems is that they transfer heat rather than produce it.

A slightly more detailed process description is that a geothermal pump exchanges air between a building and the ground by utilizing a series of pipes that cycle between the house and the earth.

In the winter this works because below the frost line, the ground stays a balmy 50 degrees Fahrenheit no matter how hot or cold it is outside. In the winter, the pump pushes that warm air into a home and replaces colder air, essentially putting the earth to work as a heat exchanger.

In the summer, the reverse happens. Warm air from inside the home is replaced with air that has been cooled by pipes running through that now relatively chilly 50-degree ground.

While it might sound complex, it is really quite simple. It is taking advantage of the solar power of the sun and the insulating properties of the earth. Think of all the animals that build burrows underground…it's the same principle at work.

While the concept might seem novel, it was first used by the Romans to heat spas and pools and it is extremely common in Iceland. Already, 15,000 systems have been installed in Michigan, according to the Michigan Geothermal Energy Association. And with rising energy costs, that number is only on the upswing.

Local Examples

Metro Detroit increasingly abounds with examples of buildings going geothermal. The biggest -- perhaps, only -- "con" for geothermal is its high upfront cost. A geothermal system can run two to three times more upfront than a new heating and cooling system. As you will read, there are some creative ways to soften that financial blow -- and for some, savings of 30 to 70 percent annually on utilities is enough of a lure.

Matt and Kelly Grocoff are renovating their Ann Arbor Victorian as top-to-bottom sustainably as possible. As would be expected, they exhaustively researched many options for their new heating and cooling system.

After doing the math on a high-efficiency traditional furnace, solar generation and geothermal, all signs pointed in one direction. "Geothermal was going to be the most cost effective way to reduce our footprint," says Matt.

Their system would end up costing $8,000 more than the most efficient heating, cooling and hot water system they could find, which is adding $40 a month to their mortgage payment.

But that number is misleading. They are saving $100 a month in energy costs, meaning they are actually netting $60 each month by using their new geothermal system.

The couple is thrilled with the results, and has become de facto geothermal missionaries. "We get tons of questions and we keep telling everyone, 'You can see what we've done,' " says Matt. "Everyone who sees its tells someone else, and now we get calls from total strangers that are interested in geothermal."

Art Roffey and Gail Danto are another couple that has extended green principles throughout the dream home they are in the process of building on a lake in Bloomfield Township.

Although the home will be 8,000 square feet counting its finished lower level, the goal is to have the home certified as LEED Gold.

Roffey says right off the bat one of things that drew he and Danto to geothermal was the comfort -- temperatures inside just do not fluctuate as much as with a traditional heating and cooling system. "But it's not just for our comfort, it's a statement of our values," he says. "There are more greenhouse gases caused by homes than by cars!"

He says that sinking 25 geothermal wells approximately 150 feet deep adds significantly to the cost of the project. He estimates it will take 10 years to repay the cost of the geothermal and solar elements of the house. "Upfront, it is definitely more expensive," he says. "Over the home's life cycle, I don't believe it will be."

He has good reason for that optimism. Beyond the savings in utility costs, a geothermal system is usually a one-time investment over the life of a building. How is that? Well, typical warranties on the pipe/well system is 25 to 50 years, but most are expected to last more like 50 to 200. The pump is a relatively minor expense in the scheme of things.

In fact, the Environmental Protection Agency called geothermal the most energy-efficient, environmentally clean, and cost-effective space conditioning systems available in a 1993 report entitled "Space Conditioning: The Next Frontier."

This cost-effectiveness can mean that geothermal is chosen by those for whom green dollars are more important than a green environment.

Jan Djikers and her parents have a small family development company in Detroit called Renovatio. For Edmund Place, their four-unit condominium conversion of a long-vacant Brush Park mansion, they ended up going geothermal after receiving an intriguing proposal from Hardin Geotechnologes Inc.. Basically, the company would forego any upfront payment for equipment and installation in exchange for payment of an annual usage fee.

"For us, the green part was secondary," says Djikers. "It was more like because the project probably wouldn't have worked if we had to pay for a new HVAC system."

In Detroit, Crosswinds Garden Lofts, a new development, has also worked with Hardin. Like Edmund Place, the geothermal plan acted as both an incentive for potential buyers with their eyes on the bottom line as well as a means for developing a tricky project.

Dollars and sense

Residential development projects aren't the only ones turning to geothermal installation. LaFontaine Cadillac in Highland is building a new facility that, much like the Roffey/Danto home, is large but still aiming for LEED certification. OK, well at 63,000 square feet, it might qualify as "ginormous."

Still, LaFontaine will be the first "green" dealership in Michigan and one of the first in the nation. Geothermal heating and cooling are part of the portfolio that also includes a car wash that recycles water and a shop that uses low-emission paint, sealants and carpet.

Meanwhile, in Southwest Detroit, the Odd Fellows Hall was recently redeveloped by the Southwest Detroit Business Association. The 15,000 square foot building received a geothermal heating and cooling system.

Developer Larry Ladomer of L. W. Ladomer & Company had never worked with geothermal before, but was quickly sold on the process. Estimating his initial installation cost will be paid back in just six years, he sums up the virtues of this quickly spreading green energy: "You have to ask yourself, am I going to build for now, or build for the future?"