Geothermal Green Energy
Geothermal Heat Pump Systems
The U.S. Environmental Protection Agency has identified geothermal heat pumps as a technology that significantly reduces greenhouse gas and other air emissions associated with heating, cooling and water heating residential buildings, while saving consumers money, compared to conventional technologies. For every 100,000 units of typically sized residential geothermal heat pumps installed, more than 37.5 trillion Btu’s of energy used for space conditioning and water heating can be saved, corresponding to an emissions reduction of about 2.18 million metric tons of carbon equivalents, and cost savings to consumers of about $750 million over the 20-year-life of the equipment.
What is Geothermal?
Geothermal heating and cooling relies on an energy exchange between ambient air and the ground. The earth absorbs nearly half of all solar energy, producing more than 500 times the energy mankind needs in a year. As a result, the Earth remains at a consistent 50 F. A geothermal unit utilizes the natural heat storage ability of the Earth and a year-round constant temperature to facilitate an energy efficient exchange of heat between the home and ground. Geothermal heating technology dates as far back to the 1930’s and has evolved to a wide variety of applications. The technology first became popular in Sweden as a result of the 1973 oil crisis and has been growing in worldwide acceptance since. Each year more than 80,000 units are installed in the United States.
What is a Geothermal Heat Pump?
Opposed to traditional heating systems engineered to create heat, geothermal systems force the transfer of heat. Geothermal heat pumps or ground source heat pumps (GSHP) are central heating and cooling systems that harness the natural heat storage ability of the earth or earth’s groundwater, relocating heat to or from the home, to provide heating, cooling, and hot water at remarkably high efficiencies. In contrast to fossil fuel systems, geothermal heat pumps emit no combustion byproduct and have the lowest Co2 emissions of any space heating unit. The heat pump device is a single indoor unit that can provide domestic or in-floor radiant hot water in addition to space heating and cooling.
How Geothermal Systems Operate?
Geothermal systems use the combination of a sealed underground loop filled with circulating water and heat pump unit to exchange heat between your home and the earth. Geothermal heat pumps, much like air source heat pumps, utilize the refrigeration cycle and compressor to relocate heat. The energy efficient distinction is where the source of heat transfer occurs. Air source heat pumps rely on a medium of inconsistent outdoor temperatures (in the Northeast can range from 5 F to 95F) where a geothermal unit is engineered to exchange heat with the ground loop that has a year-round consistent temperature.
In the winter, the earth is your source for heat. Water circulating in the loop absorbs heat from the earth and carries it to the heat pump where it is concentrated and sent as warm comfortable air throughout your home. In the summer, the earth is your sink for heat. The heat pump absorbs heat from the air in your home and transfers it cooler water circulating in the loop piping where it is absorbed by the earth.
Hot Water Generation, your “desuperheater”
The desuperheater is a small auxiliary heat recovery system that integrates with the heat pump unit to provide domestic hot water. The system transfers excess heat from the heat pump’s refrigeration cycle to a water that circulates through the heat pump and to the house’s hot water tank. In summer, when the air conditioning runs frequently, the desuperheater may provide all the hot water needed by a household (up to eight gallons per each ton of cooling, per hour of operation). This system provides less hot water during heating season, considered supplemental, and provides no hot water while the heat pump is not operating. On average, the desuperheater can provide 2/3rd’s of a home’s domestic hot water demands.
Ground Loop Structure
Your geothermal loop is custom designed to fit your exact needs and available space.
Uses a continuous loop that acts as a heat exchanger with the earth exchanging heat from the earth (or home) and loop structure. The loop system is connected to the indoor heat pump at the basement forming a sealed indoor-subterranean connection where an environmentally friendly water/anti-freeze solution is circulated.
Common Closed Loop Design
Horizontal — Where space allows the seal loop piping can be buried in trenches or bores ranging from 3 to 6 feet deep.
Vertical — Where space is limited, the seal loop piping can be inserted in small holes ranging from 150 to 400 feet deep that are installed using a drilling rig.
Open Loop Systems
Where groundwater is of adequate quantity and quality, well water can be directly used instead of the sealed loop piping. Fresh water is continuously pumped through the heat pump where heat is extracted/expelled with the water discarded to a secondary well or pond.
Geothermal heat pumps will reduce heating/cooling costs regardless of existing conditions in a home or building. According to the EPA ground source heat pumps are “the most energy-efficient, environmentally clean and cost-effective space-conditioning system for most locations in the U.S.” The combination of a high efficiency natural gas furnace and a high efficiency air conditioner will still nearly double in operating costs in comparison to a geothermal system.
The monumental impact of the current use of geothermal heat pump technology is equivalent to:
- Taking 971,000 cars off the road
- Planting 289 million trees
- Reducing U.S. reliance on imported fuels by 16.1 million barrels of crude oil every year
- Annual Savings of nearly 6,000,000,000 kWh
- Annual Savings of 30 trillion Btu of fossil fuels
- Reduced electricity demand of nearly 2 kW
- You Geothermal Advantages
- Lower Utility Bills: Geothermal heat pumps will reduce heating, cooling and hot water costs
- Earth-Friendly: Conserves natural resources and minimizes pollution with zero onsite emissions
- Comfort: Provides an even level of heating and cooling along with consistent humidity levels through long run cycles
- Safe: No fuel source, flame, or combustion byproducts
- Noise-Free: No noisy outdoor fans
- Longer System Life: All components are located indoors and free from outdoor elements.
- More Ways to Save: Federal tax credit saves you 30% on the total cost
To calculate your Geothermal Savings, click here.