Geothermal Powered
Homes
by Realty Sage
Source: GeoSmart Energy
What To Expect
Image via Dwell
What is Geothermal ?
How does Geothermal Work?
Geothermal heat pumps (GHPs) use the constant temperature of the earth as the exchange medium instead of the outside air temperature for both heating and cooling purposes.
Though many parts of the country experience seasonal temperature extremes, a few feet below the earth's surface the ground remains at a relatively constant temperature.
Switching the direction of heat flow, the same system can be used to circulate the cooled water through the house for cooling in the summer months. The heat is exhausted to the relatively cooler ground (or groundwater) rather than delivering it to the hot outside air as an A/C does. As a result, the heat is pumped across a larger temperature difference, leading to higher efficiency and lower energy use.
Chart Source: CleanTechnica
Advantages of Geothermal Energy
​
-
Mile-or-more-deep wells can be drilled into underground reservoirs to tap steam and very hot water that can be brought to the surface for use in a variety of applications, including electricity generation, direct use, and heating and cooling
​
-
Geothermal systems can save homeowners 30–70 percent in heating costs, and nearly 20–50 percent in cooling costs compared with conventional AC systems. This translates to roughly $400 to $1,500 annual savings.
-
Geothermal heat pumps are the most energy-efficient, environmentally clean, and cost-effective systems for heating and cooling buildings. All types of buildings can use geothermal heat pumps.
-
Geothermal energy is extremely reliable, requires minimal maintenance and is durable.
Source: GreenTech Media
Geothermal Energy is not always the same as Ground Source Heat Pumps
​
"Geothermal energy is considered a renewable resource. Ground source heat pumps and direct use geothermal technologies serve heating and cooling applications, while deep and enhanced geothermal technologies generally take advantage of a much deeper, higher temperature geothermal resource to generate electricity." -- Environmental Protection Agency
​
Geothermal Heat Pumps vs HVAC
​
Geothermal uses the ground as the source of the heat and as a medium to exchange heat, while an HVAC system or heat pump uses the air as the heat exchange source. However, a ground source heat pump is more energy-efficient and lasts longer than an air source heat pump or HVAC system.
​
​
There are some cases where it makes sense to get an HVAC/heat pump:
​
-
You need something installed quickly
-
The space you need to heat or cool is relatively small
-
Your property is not suited for geothermal
​
On an eight-foot-wide site in London, architect Luke Tozer cleverly squeezed in a four-story home equipped with rain-water-harvesting and geothermal systems.
Photo: Charlie Crane
Cost Comparison Heat pump/HVAC or Geothermal System
A ground source heat pump (geothermal) uses 50% less electricity than central air and lasts twice as long as an air source heat pump before it needs replacing. The following table compares some basics of Geothermal and HVAC/air heat pumps .
System Life before replacement Electricity usage Upfront cost
Geothermal system 25 years to 50 years 25% to 50% less than a HVAC $3,592 – $15,578
Heat pump/HVAC 15 years 25 to 50% more than a geothermal system $3,875 – $10,000
​
​
You don’t need a backup system for a geothermal system. Before installing a geothermal system, complex calculations are done to determine the right size heat pump to give your home enough heating and cooling.
​
It can be a good idea to have a backup, such as a gas heater or electric heater, if there is ever an issue with your geothermal system.
​
A fan or portable air conditioning unit can be a good idea for the summer, but geothermal heat pump systems are made to the strict consumer and building standards and are very reliable.
Do I Need a Backup System with Geothermal?
Source: WaterFurnace
Did you know the US is Leading in Geothermal?
​
-
With more than 3,300 megawatts in eight states, the United States is a global leader in installed geothermal capacity. Eighty percent of this capacity is located in California, where more than 40 geothermal plants provide nearly 7 percent of the state’s electricity.
​
-
Most geothermal power plants are located in the geologically active West.
​​
-
At the larger power plant level, electricity generated from geothermal sources is already cost-competitive with electricity generated by fossil fuels.
​​
-
The lifespan of an underground energy collector can be more than 100 years. The upgrade costs will only be for the next indoor heat pump (25 year lifespan)
Workers from Dandelion Energy work on a trench for geothermal loops at the home of Robert A. Culp and Vivian Linares in Garrison, NY.Credit...Andrea Mohin/The New York Times
What is The Cost of Installing a Geothermal System?
​
For a 2,000-sq.-ft home or small-scale geothermal system, costs can range anywhere from $10,000 to $30,000. Some factors that change the cost of installation include: “soil conditions, plot size, system configuration, loop system, site accessibility, and the amount of digging and drilling required”.
​
The additional cost to upgrade to a geothermal system will have returns on the 5% to 8% annually at today energy prices for propane and heating oil. So if the system cost $10K more to install, it would be like getting 5% to 8% return annually on a $10K investment.
​
Both heat pumps and geothermal systems cost on average the same amount, however, a geothermal system is 25% to 50% cheaper to run than an air heat pump.
​
​
​
A Farmhouse in Iceland’s Haukadalur Geothermal Valley. New York Times.
There are many federal, state, and local incentives that can help to offset the initial up-front costs of going geothermal. Realty Sage offers a list of resources for finding these incentives.
​
​
The actual geothermal heat pump unit is around the same size as a heat pump. But, a geothermal system takes up more space because of the hoses that are buried underground.
However, because they’re underground, you won’t notice a difference in the available space in and around your home whether you use a heat pump or a geothermal heating and cooling system.
​
Installation Time
​
It can take several weeks (6-8 weeks) to install a new geothermal system.
​
​
​
How Much Space Does Geothermal Installation Require?
Image via Dwell
Step in the installation Time it takes
Permitting and Design 2 to 3 weeks
Drilling 3 to 5 days
Trenching between boring and hose 1 to 2 days
Piping connections 2 to 5 days
Duct modification or installation 1 to 2 weeks
Electrical connections 2 to 3 days
Thermostat Set-up, zoning control, and start up 1 day
Where is Geothermal Energy Available?
Places where the Earth’s heat is closer to the surface, or regions rich in hot springs and other natural hot water reservoirs, are more suited for finding and using geothermal.
The Pacific Rim, often called the Ring of Fire for its many volcanoes, has many hot spots, including some in Alaska, California, and Oregon. Nevada has hundreds of hot spots, covering much of the northern part of the state.
​
You’ll need to consult with a geothermal energy consultant or a company that installs geothermal to assess the specific area to determine if it is suitable.
​
Blauhaus residence in North Carolina powered by geothermal energy. Source.
What Are Some Installation Options?
​
If your home is not suitable for geothermal, it's worth considering other options for energy.
​
Realty Sage is partnered with Energy Sage to help you get estimates from local providers. Read more about alternative energy options such as wind and solar energy, as well as passive solar homes.
​
Considering switching to geothermal for your home? Undecided explains in more-depth how Geothermal energy works. As you consider options, it is important to note there are 6 major types of geothermal heat pumps:
​
-
Closed loop
-
Horizontal
-
Vertical
-
Pond/lake
-
Open-loop
-
Hybrid
​
​
Scroll below to explore several companies offering geothermal energy installation.
​
​
​
​
​
​
​
​
​
​
​
​
​
​
​
1. Dandelion Energy
​
​
Cost: Financing payment starts at $0 down and $150/month. Dandelion Geothermal starts at just over $18,000 – $25,000 (after federal, state, and utility incentives) for a 3 - 5 ton heat pump system which includes all installation costs.
​
Website: https://dandelionenergy.com/
​
Pricing/ Savings Breakdown: https://dandelionenergy.com/geothermal-pricing-guide
Who Should Use Them: If you are a U.S. homeowner looking for a cheaper and cleaner solution to heat and cool your home, geothermal could be a fit for you. A five-ton Dandelion Geothermal System reduces a home’s carbon footprint by 60-85% when switching from natural gas, propane, or fuel oil, respectively. Check out Dandelion if your state, like New York, Massachusetts, Connecticut, Maryland, New Jersey, and Pennsylvania, offers special incentives for geothermal.
​
What They Do: Geothermal systems use the difference in temperature to transfer heat between your home and the earth. Whether it’s a winter cold snap or a summer scorcher, the ground five feet below the surface maintains a constant temperature year round. The Dandelion Energy home geothermal system replaces your air conditioning and heating equipment with a powerful heat pump and safe, underground pipes. In the winter, the ground loops move heat stored in the ground into your home. In the summer, the ground loops returns heat from your home to the ground.
​
​
​
Financing Options: "The amount of funding available to each project will depend on its size and the heat pumps capacity. Smaller projects (e.g., residential and small commercial buildings) get $1,500 to $2,000 per 10,000 BTU of the heat pump for most utility areas we cover. So a typical 4 ton residential system will qualify for about $6,000"
​
Website: http://aztechgeo.com/
​
Who Should Use Them: Residents in Upstate NY. For Upstate NY homes heated with Propane, Heating Oil, or Electric Baseboard:
-
A geothermal system will save 40-75% on annual heating and cooling costs.
-
The savings alone often cover any monthly loan payment or increases in mortgage.
-
Payback periods are typically 5 to 8 years for retrofit and 3 to 5 years for new homes.
-
Electricity used by the heat pump can be offset by renewable Photovoltaic (PV) Solar.