The Pros and Cons Geothermal Energy for Your Home (2024)

Geothermal energy has been gaining popularity as an eco-friendly way to heat and cool a home at a fraction of the cost of fuel-burning systems or even conventional air-source heat pumps.

Geothermal HVAC, also known as ground-source heat pumps, is an eco-friendly and cost-effective way to heat and cool your home by harnessing the stable temperatures found underground. By using the earth as a heat source in winter and a heat sink in summer, geothermal systems can provide highly efficient, reliable comfort year-round.

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While this energy source does offer a lot of benefits, it’s not ideal for everyone. If you’re considering having a geothermal (ground-source) heat pump installed in your home, get to know what this system can do for you, as well as the challenges involved in having one put in.

Kindness to the Environment
Lower Heating and Cooling Bills
Longevity and Minimal Maintenance Needs

These are just the pros & cons at a glance. For a more in-depth review of geothermal energy, keep reading, then check out our video on the basics of geothermal heating systems.

The Pros: Lower Bills and Greater Reliability

Geothermal is one of the most reliable energy sources there is, and the efficiency of geothermal heat pumps means they cost little to run.

Unfailing Reliability

Fossil fuels, such as oil and natural gas, aren’t easily renewable, so the oil and gas industry is continually developing new ways to find, recover, and conserve these fuels. While there’s debate over whether we’ll ever run out, the fact remains that these fuels are a dwindling resource.

To make matters worse, prices fluctuate unpredictably due to economic and political events.

Residential solar power, while highly renewable and safe from the effects of international events, isn’t a practical option everywhere. Even in areas where solar power is a viable way to heat and cool a home, varying weather conditions make it somewhat unreliable.

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Geothermal energy is drawn from heat generated by Earth’s core, so it will never become harder to extract, and there’s no risk of exhausting it with residential heat pumps. This heat is relatively constant year round, so your home won’t be at the mercy of the weather. Because geothermal energy doesn’t have to be imported, political events won’t affect your energy costs.

Lower Heating and Cooling Bills

Lower bills are one of the biggest draws of geothermal energy, and when used for home heating and cooling, it definitely delivers. Not only are geothermal heat pumps more efficient than fuel-burning systems, they’re also three to five times more efficient than conventional air-source heat pumps.

The efficiency of an air-source heat pump depends in part on the outdoor air temperature, which fluctuates greatly throughout the year. Because a geothermal system uses the ground, which stays at a relatively constant temperature, it can run more efficiently than an air-source model. A geothermal heat pump can also provide you with hot water, so you’ll save money there, too.

Your exact savings depend on your climate and how much you run your heat pump. On average, most households save between 30 to 60 percent on heating and 25 to 50 percent on cooling.

Kindness to the Environment

Geothermal energy is one of the most environmentally friendly, least polluting sources of energy there is. It has less impact on the Earth than any other power source. With no mining, processing or shipping involved, using geothermal energy to heat and cool a home is a nearly emission free process.

Geothermal heat pumps need a source of electricity to run, but you can make them more eco-friendly by installing solar panels to power the pump.

Longevity and Minimal Maintenance Needs

A geothermal heat pump will outlast nearly any other heating and cooling system. The pumps run reliably for around 20 years, longer than a conventional air-source heat pump, boiler or furnace. The ground loops typically come with a warranty for 25 to 50 years, but they can remain usable for as long as 200 years.

With few moving parts in these systems, there’s little that can go wrong, so breakdowns are rare. You’ll need to have annual maintenance performed, and open-loop, water-source systems require a little extra care due to mineral and sediment buildup.

Unlike air conditioners and air-source heat pumps, geothermal heat pumps have no outdoor parts. There’s nothing outdoors you’ll need to clean, clear plants away from or protect from storms and vandalism.

Widespread Availability

Because all parts of the planet contain some geothermal energy, a geothermal heat pump can be installed nearly anywhere. If your property doesn’t have the space for a horizontal ground loop, a vertical ground loop is an alternative option. A vertical loop takes up less ground-surface space, but it’s also more expensive to install.

The Cons: High Installation Costs and Specific Site Requirements

The cost of geothermal systems is falling, but they’re still more expensive to install than traditional heating and cooling systems. What’s more, not every site is ideal for geothermal.

High Upfront Costs

One of the biggest drawbacks that puts many homeowners off switching to a geothermal heat pump is the high initial cost of installing one. A system for the average-size home runs between $10,000 to $20,000.

If you’re planning to install any new heating and cooling system, first take steps to improve your home’s energy efficiency, such as upgrading your attic insulation. Doing this lets you install a smaller, and therefore cheaper, system as well as enjoy lower monthly bills.

By rewarding you with lower bills, an investment in a geothermal system usually pays off within five to 10 years, depending on your heating and cooling needs.

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If you plan to sell your house within the next 10 years, the investment might not be worth it.

Site Requirements

Not all locations are equally well suited to using geothermal energy. Some areas have more ground heat than others due to volcanoes and other natural features. In the United States, homes on the west coast will get better results than those in the Midwest and southeast.

For a heat pump with a ground loop, how close the bedrock is to the soil surface and the type of soil you have are influential factors. For instance, where the soil is shallow, a vertical ground loop might not be possible.

If you’re considering a water-source geothermal system, you’ll need a nearby body of water that can supply 1.5 gallons of water per minute for every ton of heating and cooling capacity your home needs. Many locations just can’t supply that flow rate.

In addition, the mineral content and pH of your water should be suitable for use with a geothermal heat exchanger. If you don’t have a nearby natural body of water, such as a pond or stream, that’s large enough to handle the water used by your heat pump, you’ll need to have a return well installed.

For a reliable, environmentally friendly, and low-cost way to heat and cool your home, it’s hard to beat geothermal energy. Before you set your heart on installing a geothermal heat pump, though, get a solid estimate of how much it will cost to install and how long your payback period will be.

If the upfront costs are outside your budget or your property isn’t well suited to geothermal, another eco-friendly option, such as solar power, might be a better choice.

How Do Geothermal HVAC Systems Work?

Geothermal HVAC systems take advantage of the relatively constant temperatures found a few feet below the earth’s surface. In winter, the heat pump extracts heat from the ground and transfers it into your home. In summer, the process is reversed, and the heat pump moves heat from your home into the cooler earth.

The geothermal heat pump system consists of three main components: the ground heat exchanger (the loop system), the heat pump unit, and the air delivery system (ductwork). The heat exchanger is a network of pipes buried in the ground, while the heat pump unit compresses and circulates the refrigerant to transfer heat. The ductwork distributes the conditioned air throughout your home.

Geothermal systems are highly efficient because they move heat rather than generate it. They can deliver three to five units of energy for every one unit of electricity consumed, resulting in significant energy savings compared to traditional HVAC systems.

Types of Geothermal Heat Pump Systems

Closed-Loop Systems

Closed-loop geothermal systems circulate an antifreeze solution through a closed network of underground pipes buried several feet underground. The fluid absorbs heat from the earth in winter and releases heat into the ground in summer. Closed-loop systems can be installed horizontally, vertically, or in a pond/lake and are most common for homes.

Open-Loop Systems

Open-loop systems use groundwater from a well as the heat exchange fluid. The water is pumped into the heat pump unit, where heat is extracted or injected and then returned to the ground through a discharge well. Open-loop systems are less common and require an adequate supply of clean water.

Direct Exchange (DX) Systems

DX systems use refrigerant lines buried underground as the heat exchange medium, eliminating the need for an intermediate fluid. The refrigerant directly absorbs or releases heat to the ground. DX systems are highly efficient but less common than closed-loop systems.

How Much Do Geothermal Heat Pumps Cost?

The up-front cost of installing a geothermal heat pump system is higher than traditional HVAC systems, typically ranging from $10,000 to $30,000, depending on the size of your home, the type of system, and site conditions. However, geothermal systems offer substantial energy savings, with most homeowners seeing a return on their investment within 5–10 years through lower utility bills.

Final Thoughts

Geothermal HVAC systems are an environmentally friendly, energy-efficient, and cost-effective alternative to traditional heating and cooling systems. While the initial installation costs are usually more, the long-term energy savings and reliability of these systems make them an attractive option for many homeowners.

However, you should consider your location, site conditions, and budget when deciding if geothermal is the right choice for your home. Consult with a qualified HVAC professional to assess your property and provide a detailed quote before making a final decision.

Frequently Asked Questions

Can geothermal systems provide hot water?

Yes, some geothermal heat pumps can be equipped with a desuperheater, which allows the system to provide hot water for your home.

Are geothermal systems noisy?

No, geothermal systems are very quiet since the compressor is located inside the home, and there is no outdoor unit.

Can geothermal systems be installed in existing homes?

Yes, you can retrofit geothermal systems into existing homes, although installation costs may be higher than in new construction.

Are there any government incentives for installing geothermal HVAC?

Yes, there are federal tax credits and sometimes state or local incentives available for installing geothermal systems, which can help offset the initial cost.

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Reviewed for accuracy, cost data, industry best practices, and expert advice by Jonathon Jachura.

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