If you are thinking about bigger ways to go green – geothermal energy may be on your list. Geothermal energy is when heat is gathered from below the earth’s surface, which can then be harnessed to heat or cool your home. It is one of the best ways to get clean, renewable energy, according to the U.S. Department of Energy. But there are upsides and downsides to everything, so let’s take a look at the pros and cons of making the switch to geothermal energy.
This may seem obvious, since you are using the earth itself to heat and cool your home, but geothermal units are environmentally friendly. The geothermal systems we are talking about are more accurately called ground water source heat pumps. They emit no gases of any sort, but they do consume electricity to operate. Still, they consume electricity in a miserly way, using very little to extract heat from the earth.
Low Cost To Operate
Geothermal costs way less to operate compared to even the more efficient natural gas HVAC system.
“It is currently the most energy efficient system to heat a home,” according to our resident energy expert, Keith Hill, technical support manager for Minnesota Air.
Reliable Temperature Control
Keith says the key to geothermal is that the soil beneath our feet stays a stable 50 to 60 degrees year round.
“Even during our arctic winters, the frost sets only so far, 4 to 6 feet in most parts of Minnesota. But go further down, and the soil temps are much warmer and very constant,” he says. “Using the stable earth temperature as a heat sink enables ground water source heat pumps to be extremely efficient both capturing heat and rejecting heat during the cooling mode.”
It Doesn’t Take Up Much Above-Ground Space
Not only does it have a small carbon footprint, but it has a pretty small land footprint, too. Since the majority of the system is doing the work underground, it takes up far less space than you’d imagine.
Real Renewable Energy
Geothermal is renewable… really renewable. Because you are using the Earth itself for energy, as long as the world keeps spinning and we keep living on it – geothermal energy will continue to be an option. According to the Department of Energy, we have an “almost unlimited amount of heat generated by the Earth's core. Even in geothermal areas dependent on a reservoir of hot water, the volume taken out can be reinjected, making it a sustainable energy source.”
Expensive To Install
Perhaps the biggest downside right now with geothermal energy is the upfront cost to get a unit installed and the in-ground portion set up at your home. According to the energy design website, Energyhomes.org, a typical home of 2500 square feet will cost between $20,000 to $25,000 to install.
Keith says the two most common earth heat exchange systems are loops of plastic piping buried deep in the backyard or in vertical wells (with the plastic pipe installed in wells similar to a water well). That means you’ll need to get a crew to dig and drill.
“Buried loops are usually less costly than wells, but require much less real estate. The vertical wells are much less intrusive to the yard and can be installed on even the smallest of residential lots,” he says.
You’ll Still Need Another Energy Source
In order to power the geothermal pump that brings the heat inside your house from the earth, you’ll still need another source of energy in order to get the pump to work. It needs minimal electricity, so you can use conventional electricity (from the grid), or if you really want to stick with environmentally friendly options, you can always install solar panels or a small wind turbine. Of course, that adds to the overall upfront cost, but can pay for itself in the long run.
If you are interested in looking further into geothermal energy, we’d recommend looking into energy.gov’s article on choosing and installing geothermal heat pumps. They even list rebates and incentives for making the choice to switch.