Online Article

GEOTHERMAL ENERGY

Geothermal energy has been used for thousands of years in some countries for cooking and heating. It is simply power derived from the Earth's internal heat. This thermal energy is contained in the rock and fluids beneath Earth's crust. It can be found from shallow ground to several miles below the surface, and even farther down to the extremely hot molten rock called magma.

These underground reservoirs of steam and hot water can be tapped to generate electricity or to heat and cool buildings directly.

A geothermal heat pump system can take advantage of the constant temperature of the upper ten feet (three meters) of the Earth's surface to heat a home in the winter, while extracting heat from the building and transferring it back to the relatively cooler ground in the summer.

Geothermal water from deeper in the Earth can be used directly for heating homes and offices, or for growing plants in greenhouses. Some U.S. cities pipe geothermal hot water under roads and sidewalks to melt snow....
[click to be redirected to the complete article on the National Geographic website]

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GET BLUEPRINTS FOR A GREEN HOUSE
By Laura Locke

Reducing your impact on the earth is not just a question of what you drive but also of what you live in. Residential energy use accounts for 16% of greenhouse-gas emissions. If you begin thinking green at the blueprint stage, however, low-tech, pragmatic techniques will maximize your new home's efficiency. Installing those systems from the ground up is cheaper than retrofitting. "Doing simple things could drastically reduce your energy costs, by
40%" says Oru Bose, a sustainable-design architect in Santa Fe, N.M. For example, control heat, air and moisture leakage by sealing windows and doors. Insulate the garage, attic and basement with natural, nontoxic materials like reclaimed blue jeans. Protect windows from sunrays with large overhangs and double-pane glass. Emphasize natural cross ventilation. "You don't need to have 24th century solutions to solve 18th century problems," Bose says. Next, consider renewable energy sources like solar electric systems, compact wind turbines and geothermal heat pumps to help power your home.
[click to be redirected to the complete article on the TIME Magazine website]

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Yankee Ingenuity:
A New England home uses innovative, eco-friendly technology
Laurel Kallenbach

Clad in unpretentious wood-shingle siding, Sally and Tony Grassi’s coastal Maine home looks every bit the stoic New England farmhouse. Yet beneath its traditional exterior is cutting-edge environmental innovation: A blend of geothermal and solar power generates the energy the couple uses, plus the home employs a host of environmentally sensitive building techniques.

Tony and Sally’s goal was to create a nontoxic, eco-friendly home that reflects their environmental ideals. They declared independence from nonrenewable energy and banned PVC, a planet-polluting plastic, from their house. They also insisted on sustainably forested, formaldehyde-free wood for both framing and finishes.

Set back from the ocean on an 18-acre parcel of field and forest, the house and accompanying buildings occupy the site of a house removed by a former landowner. “We didn’t want to make a new scar on the land,” Tony says. The couple built a cluster of buildings around a central courtyard: the main house (with kitchen, living room, dining room, office, master bedroom and guest room), a guest house (with three more bedrooms) and a workshop/garden house. A pony barn, which houses the complex’s solar panels, is farther away in an open field. No trees were cut to make room for the new buildings.

“We wanted to keep the house small but have enough room for our extended family for holidays,” Sally says. Locating most of the guest rooms in a separate building allows them to turn off the power there until company comes ....
[click to be redirected to the complete article on the Natural Home Magazine website]

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U.S. News and World Report
December 20, 2007

Warm Up to Geothermal
by David LaGesse

Solar panels look bold on a rooftop, and a Toyota Prius looks hip in the driveway. Geothermal heating and cooling has none of that sex appeal, yet perhaps unlike the others, it can clearly save you money—and a lot of it. "The problem is that we don't have some big, fancy piece of equipment outside," says John Kelly, head of a Washington trade group for geothermal companies.

Instead, the secret gets buried. Literally, in the backyard, where drillers might sink several holes deep into the ground for a system that sucks heat out of the earth in the winter and cold in the summer. It's tried and true, can cut utility bills by half, and does away with noisy air conditioning condensers by the back patio. "It's a no-brainer," says Jim Damiani of Edmond, Okla. He helped run two big companies—Lennox and York, which make conventional HVAC systems, and has installed geothermal in his last two homes.

Yet lots of people with brains stick with the conventional. Less than 1 percent of U.S. homes has geothermal systems, and that's decades after the technology emerged as a proven energy saver. The biggest hurdle is the upfront price. A geothermal system can cost twice as much as a new conventional gas or electric system. The difference is in those holes. Drillers might need four 150-foot holes for a typical suburban home. Then a loop of plastic pipe is inserted, covered with dirt, and hooked to inside gear that looks much like conventional furnaces. The inside units pump water into the ground, causing it to emerge at a constant ground temperature, typically about 55 degrees Fahrenheit. That's obviously enough to cool a house in the summer, and compressors can eke out enough heat for almost all but the bitterest winter days. Supplemental electric heat helps on the coldest days.

Buyers' advantage. To get their money back, homeowners might need to stay in the house at least three years, and maybe as long as 10. Or they need a buyer who understands the advantages. Appraisers, at least, have started to add value to homes with geo-thermal systems, but not many real-estate agents and builders have joined the parade, says Daniel Ellis, president of ClimateMaster, which makes geothermal systems. He says builders don't let homeowners choose a lot of the big stuff, like heating and cooling. "They'll just ask about the granite and flooring."

Or the technology needs a significant tax break, which so far Congress has not granted. The feds haven't ponied up partly because geothermal, unlike other green technologies, is a proven profit maker. "It's already a sweet deal," says Jim Bose, whose group at Oklahoma State University researches geothermal and trains contractors. "How sweet a deal do you need?"
[click to be redirected to the complete article on the U.S. News and World Report website]

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Geothermal Heat Pump Consortium
GeoExchange.org

Geoexchange Heating and Cooling Systems: Fascinating Facts

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-live of the equipment.

Geothermal heat pump systems, also known as "geoexchange," are the most energy-efficient, environmentally clean, and cost-effective space conditioning systems available, according to the Environmental Protection Agency.

Geothermal heat pumps strengthen U.S. energy security.  Every 100,000 homes with geothermal heat pump systems reduce foreign oil consumption by 2.15 million barrels annually and reduce electricity consumption by 799 million kilowatt hours annually....
[click to read the entire pdf file on the GeoExchange.org website]

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Exploring Energy Efficiency Using Geothermal Heat Pumps
by Andrew Lake

A geothermal heat pump, like an air source heat pump, moves heat from one location to another. But unlike an air source unit, it exchanges heat with the ground instead of the outdoor air. This enables it to operate more efficiently, as the temperature of the earth more than 5 ft. below the surface is nearly constant all year round, being warmer in the winter when the heat pump is absorbing heat from it, and cooler than the air in the summer when heat must be released into it.

Geothermal heat pumps have a heating efficiency rating called the coefficient of performance (COP). The COP is the number of watts of heat energy the unit can move into the house for every watt of electricity consumed. New systems have COP's between 3 and 4.5. The unit can operate at this high efficiency level every day of the year.

A COP in the 4-4.5 rang equates into heating cost savings of 30-75%. The savings vary depending on your current systems efficiency (you can save more if you're upgrading from an older natural gas system or even more so if you currently use heating oil) and the electricity rates in your area (electricity is cheapest in the Northwest and most expensive in the Northeast.) Unlike with an air source heat pump, savings do not vary much depending on the winter climate.

Add air conditioning and save on water heating as well

• If you have a forced air heating system (furnace) a geothermal heat pump will provide you with air conditioning without the installation of any additional equipment. It will use only about half as much energy as a newer air conditioner.
• If you have radiant heating, the lines in your floor are unsuitable to circulate cool water, so special indoor fan units will have to be installed. If you insist on having these units installed in several rooms in your home, they can hugely increase the cost.
• If you have baseboard hot water heating, a geothermal unit is unsuitable for your home, as it cannot supply the higher water temperatures required by these systems.
  A special unit called a desuperheater can be installed with a geothermal heat pump. It will use the heat pump to preheat the water up to 120F before it enters the hot water tank. This can cut your hot water costs by about half as well.

Types of geothermal heat pump installations

There are four ways to run the underground piping that is required for a geothermal heat pump: in a horizontal closed loop, a vertical closed loop, a pond loop, or an open loop setup.

Through one of these loop systems, the heat pump will acquire water which has been heated up (or, in the summer, cooled down) to ground temperature. In a closed loop setup, about 1000 feet of pipe must be buried to heat a typical 2000 square foot home. In a horizontal closed loop setup, the pipes will be buried about 5 feet below the ground. This will require a very large yard. For most homes, only a vertical loop system will fit in the yard. This involves drilling a series of wells about 200 feet deep to place the pipes in. Installation of a vertical loop system can cost up to twice as much as a horizontal loop system.

If you have a large pond on your property, you're in luck. Loops of pipe can be dropped into the pond, and this will be less expensive than a horizontal loop setup.

Open loop setups are now growing in popularity. These systems pump water from an aquifer (underground rocks that have water flowing through them) from one well and return it to the same aquifer using another well. If you have an aquifer with a high enough water flow rate not too deep beneath your property, then you may be able to drill only two wells to depths as low as 100 feet to meet your geothermal heating needs. This can be less expensive than other loop options, but even in areas with ideal aquifers, many contractors are just beginning to look into installing them.

Cost of geothermal

Geothermal heat pumps sound great when the energy savings and the benefit of adding air conditioning are described, but most homeowners will lose interest when the cost of the installation is brought up. These unit are priced similarly to new cars, so for a typical home it will take 20 years or more to earn back the initial investment. However, some homes may have payback periods of less then 10 years. These are usually larger homes in areas with lower electricity costs which are currently using oil or older natural gas systems. If the homeowners require a new air conditioner or boiler (a geothermal heat pump will still require a furnace for back-up heat in forced air systems), then this cost will also be saved.

Environmentally friendly

Next to automobiles, home heating is the top source of personal greenhouse gas emissions. The average furnace or boiler actually produces more ghg's than the average car. With a geothermal heat pump, you can cut these emissions down to a fraction of their former levels. Heat pump systems do not produce any emissions on their own, but emissions are generated by electricity production. If the electricity you use is being created by burning coal, then you might decrease your ghg emissions by about 50%. If the electricity is being produced cleanly by a method such as hydro, then your heating will be responsible for a very small amount of greenhouse gas emissions.

For this reason, your local government or utilities may be providing rebates for homeowners who go geothermal.
[click to be redirected to this article on the Birds-Eye.net website]

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Online Article
Sunday, November 18th, 2007

U.S. Homebuilding is Way Down,
but WFI Industries’ Geothermal Heat Pump Sales Are Way Up – & Still Climbing

“People are telling us they want to do the right thing. They want to be green,” says Bruce Ritchey, president of WFI Industries Ltd., as he explains why, despite the borderline depression that the U.S. housing market is in, sales of WFI’s geothermal heat pumps for homes and other buildings is way up – and likely to go higher.

The geothermal heat pump is a green technology which, unlike solar and wind power, doesn’t get a lot of attention. Geothermal heat pumps utilize the Earth’s constant temperature to heat and cool water that is pumped underground through a closed loop pipe that runs up into a house or other building. Geothermal heat pumps are an environmentally-friendly source of heating, cooling and hot water

Fort Wayne IN-based WFI Industries, which trades on the Toronto stock exchange, has been in the geothermal heat pump business for decades. But after long being only an “insignificant niche” in the home heating and cooling market, geothermal heat pumps have started going mainstream, Ritchey said.

To be sure, geothermal heat pumps have long been mainstream in other countries such as Switzerland and Finland. While geothermal heat pumps still account for less than 1% of the U.S. heating and cooling market, Ritchey said his company was starting to take away business from natural gas in suburban areas of America. He added that the company was doing more work with existing housing, replacing oil burners and the like with the kind of green system more consumers now want.

“We’re at a tipping point,” Ritchey said, explaining that high fuel prices and the impact of Al Gore’s global warming campaign on the public conscience have helped push up WFI Industries’ sales and profits.

WFI Industries most recently reported third quarter net income of approximately $3.36 million or 28 cents a share, compared with $3 million or 25 cents a share in the prior-year period. Sales were up more than 17% to approximately $28.4 million compared with $26.1 million. The company also just raised its quarterly dividend to 17 cents a share, payable Dec. 3 to holders of record Nov. 16.

As good as all that sounds, Ritchey indicated during an interview that even better times should lie ahead. “We’re poised to grow,” he said, noting that there could soon be new federal and more state legislation in the U.S. that incentivizes people to put in geothermal heat pump systems. (WFI also does significant business in the Toronto area.)

Ritchey said he does not give guidance but that, if he did, “It would be a gas.” He quickly added that the growth his company is seeing likely is being seen by many other green building materials companies. “Everyone is doing well even though the (housing) market is in a tank,” he said.
[click to be redirected to this article on the EnergyTechStocks.com website]

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Geothermal Heat Pumps

Geothermal heat pumps (sometimes referred to as GeoExchange, earth-coupled, ground-source, or water-source heat pumps) have been in use since the late 1940s. Geothermal heat pumps (GHPs) use the constant temperature of the earth as the exchange medium instead of the outside air temperature. This allows the system to reach fairly high efficiencies (300%-600%) on the coldest of winter nights, compared to 175%-250% for air-source heat pumps on cool days.

While many parts of the country experience seasonal temperature extremes—from scorching heat in the summer to sub-zero cold in the winter—a few feet below the earth's surface the ground remains at a relatively constant temperature. Depending on latitude, ground temperatures range from 45°F (7°C) to 75°F (21°C). Like a cave, this ground temperature is warmer than the air above it during the winter and cooler than the air in the summer. The GHP takes advantage of this by exchanging heat with the earth through a ground heat exchanger.

As with any heat pump, geothermal and water-source heat pumps are able to heat, cool, and, if so equipped, supply the house with hot water. Some models of geothermal systems are available with two-speed compressors and variable fans for more comfort and energy savings. Relative to air-source heat pumps, they are quieter, last longer, need little maintenance, and do not depend on the temperature of the outside air.

A dual-source heat pump combines an air-source heat pump with a geothermal heat pump. These appliances combine the best of both systems. Dual-source heat pumps have higher efficiency ratings than air-source units, but are not as efficient as geothermal units. The main advantage of dual-source systems is that they cost much less to install than a single geothermal unit, and work almost as well.

Even though the installation price of a geothermal system can be several times that of an air-source system of the same heating and cooling capacity, the additional costs are returned to you in energy savings in 5–10 years. System life is estimated at 25 years for the inside components and 50+ years for the ground loop. There are approximately 50,000 geothermal heat pumps installed in the United States each year.
[click to be redirected to this article on the U.S. Department of Energy website]

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Benefits of Geothermal Heat Pump Systems

The biggest benefit of GHPs is that they use 25%–50% less electricity than conventional heating or cooling systems. This translates into a GHP using one unit of electricity to move three units of heat from the earth. According to the EPA, geothermal heat pumps can reduce energy consumption—and corresponding emissions—up to 44% compared to air-source heat pumps and up to 72% compared to electric resistance heating with standard air-conditioning equipment. GHPs also improve humidity control by maintaining about 50% relative indoor humidity, making GHPs very effective in humid areas.

Geothermal heat pump systems allow for design flexibility and can be installed in both new and retrofit situations. Because the hardware requires less space than that needed by conventional HVAC systems, the equipment rooms can be greatly scaled down in size, freeing space for productive use. GHP systems also provide excellent "zone" space conditioning, allowing different parts of your home to be heated or cooled to different temperatures.

Because GHP systems have relatively few moving parts, and because those parts are sheltered inside a building, they are durable and highly reliable. The underground piping often carries warranties of 25–50 years, and the heat pumps often last 20 years or more. Since they usually have no outdoor compressors, GHPs are not susceptible to vandalism. On the other hand, the components in the living space are easily accessible, which increases the convenience factor and helps ensure that the upkeep is done on a timely basis.

Because they have no outside condensing units like air conditioners, there's no concern about noise outside the home. A two-speed GHP system is so quiet inside a house that users do not know it is operating: there are no tell-tale blasts of cold or hot air.
[click to be redirected to this article on the U.S. Department of Energy website]

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This Old House Magazine
Summer 2008

Geothermal Heat Pump: How It Works
by Max Alexander

 ....Even with this significant front-end investment, geo­thermal systems are so energy-stingy that the payback period is remarkably brief. A study by the Air Force Institute of Technology calculated that it takes on average just seven to eight years to recoup costs. Your actual break-even point depends on local utility rates, excavation/drilling costs, how well your house is insulated, the efficiency of the model you choose, and what incentives your state or utilities provide. A good installer who's knowledgeable about heating and cooling as well as your local geology will be able to make those calculations for you.

The current federal incentive is limited to the standard $300 tax credit for Energy Star HVAC installations. (Canadians retrofitting an existing home with geothermal qualify for a $3,500 federal grant.) Some forward-thinking utilities have offered low-interest loans to homeowners willing to adopt the technology. "It's a win-win arrangement," says Steve Rosenstock, energy solutions manager at the Edison Electric Institute, an association of utilities. "The utilities reduce peak demand for heating and cooling as their customers dramatically lower their electric bills." And because the plastic ground loops should last 50 years or more, the payoff for homeowners, and for the environment, can last for generations....
[click to be redirected to the complete article on the This Old House website]

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