What Is Geothermal Energy?

When we think about winter, most of us envision snowy days, blustery winds, and ice storms. And, you can’t picture any winter scene without remembering the bitter cold most of the country experiences each season.

Keeping our homes comfortable inside while it’s freezing outside takes a lot of energy. And this energy use results in plenty of environmental pollution.

The neat thing about the Earth is that it can be -20 degrees outside, but just a few feet below the surface the temperature stays a steady 45-75 degrees, depending on the latitude.

And what does this have to do with heating your home?

Well, geothermal energy takes advantage of the Earth’s stable underground temperature, and uses that energy to heat your home. It’s incredibly clean; in fact, the Department of Energy (DOE) and the Environmental Protection Agency (EPA) have both stated that geothermal heating is one of the most environmentally friendly and efficient ways to heat and cool your home.

Let’s take a look at geothermal energy, and all it has to offer.

How Geothermal Works

Have you ever thought about how a traditional furnace works?

Basically, a traditional furnace takes the outside air, heats it up, and then blasts that hot air into your home. Now when the temperature is 50 degrees outside, the furnace doesn’t have to use too much energy to get that air up to the 68 degrees your thermostat is set at. That’s only a rise of 18 degrees.

But imagine it’s 10 degrees outside. Your furnace now how to expend much more energy to raise the temperature of that super cold air up to 68 degrees, which is a 58 degree difference.

Geothermal is efficient because it uses the stable underground temperature to heat your home.

A home using geothermal heating has an extensive series of pipes buried 5-10 feet underground. Air, or a fluid consisting of water and antifreeze, is constantly pumped through these underground pipes.

Inside your home is a heat pump, and the heat pump’s job it to extract the heat that’s already in the 50 degree water (or air) that’s in the pipes.

Now, water has the ability to store far more heat than air does. According to Sunteq Geo Distributors, there is 3,472 times more heat stored in a cubic foot of water than a cubic foot of air. This means that the heat pump is using far less energy to extract the stored heat in the water than a traditional furnace is using to extract heat from the outside air.

It doesn’t matter how cold it is outside; the air or liquid that’s being pumped underground stays relatively warm.

And geothermal systems also do the opposite in summertime. Remember, the ground temperature is at 50 degrees, even if it’s 90 degrees outside. So geothermal works to cool your home by taking that hot indoor air and running it through the underground loops. When it’s pumped back in, it’s nice and cool.

The Benefits of Geothermal Systems

There are several benefits to using geothermal systems.

• Geothermal energy is extremely efficient. The U.S. Dept of Energy (USDE) estimates that these systems have a 300%-600% efficiency on the coldest winter nights, versus 175%-250% of air source heat pumps.

• The USDE also estimates that geothermal systems also use 25%-50% less energy than traditional systems. They also help keep a home’s humidity level at a stable 50%, which reduces the need for humidifiers or dehumidifiers.

• Geothermal systems don’t need near as much indoor space as a traditional forced air furnace. This space can be used for more productive purposes in the home.

• Geothermal systems last a long time. Indoor components usually last 25 years, and ground loops are good for 50 years or more.

• These systems are also incredibly quiet. There’s no sound of machinery as a furnace kicks on.

• Geothermal systems can also be used to heat your hot water, saving you even more on your energy bills.

Types of Geothermal Systems

There are four main types of geothermal systems.

Closed-Loop Horizontal System

This installation is commonly used in residential construction because there is usually more land available. The pipes are generally buried in two rows, five feet underground.

Closed Loop Vertical System

A closed loop vertical system is often used in large commercial buildings or schools. These buildings usually have less land to work with, so the pipes are sunk deeper into the ground, usually down to 400 feet.

Pond/Lake Systems

If your land has a pond or lake, then this is the most economical option for geothermal heating. Pipes are sunk to the bottom of the pond. But, there are strict requirements on depth and volume to make sure the pipes don’t freeze.

Open Loop System

An open loop system, also called a groundwater heat pump, is used when there is plenty of clean, fresh water available underground. A secondary pump is used to pump this water into a heat exchanger, where heat is either added or subtracted (depending on the season).

Costs Of A Geothermal System

The good news about geothermal is these systems can really take a chunk out of your heating and cooling costs.

The bad news? The systems are fairly expensive to install. But, the USDE estimates that most homeowners will recoup their investment in only 5-10 years. And, thanks to state and Federal Tax credits, you can save up to 30% on a geothermal system.

If you’d like to see just how many tax credits you’re eligible for, you can visit the Database of State Incentives for Renewables and Efficiency (DSIRE).

As far as how much you can expect to spend, the California Energy Commission estimates that the average home is going to need a system that costs around $7,500. But, that’s just the cost of the system. Remember, you also have to have a pretty big hole in the ground. Which means you have to factor in digging and drilling as well.

Depending on your location and terrain, drilling is going to cost an additional $10,000-$30,000.

But, don’t give up on geothermal just yet! Remember when we said you’d recoup your costs in 5-10 years? Well, it’s still true. That’s how energy efficient these systems are once they’re installed and working. And remember, you’re going to save a fair amount with state and local tax credits, which will help ease the cost.