Ultra Geothermal in the News
Ultra Geothermal Finds Savings Underground
By Heikki Perry | Published April 28, 2014 | Foster's.com business
BARRINGTON, N.H.— Although the technology is more expensive up front, geothermal energy’s down-the-road savings are practically unrivaled.
Depending on local geologic conditions, however, one method of harnessing geothermal energy can prove superior to the other, and that’s where Barrington-based Ultra Geothermal has made its mark.
Studies have showed geothermal energy to be four to five times as efficient as standard heating oil, making it one of the most long-term cost-efficient energy solutions anywhere. Adding to this outstanding efficiency, geothermal systems may save a homeowner 60 to 70 percent in heating costs, and 70 to 80 percent in cooling costs. When federal-sponsored tax incentives and interest-free loans are added to the mix, many price- and sustainability-conscious consumers opt for a geothermal system.
Geothermal heat pumps have been in use since the late 1940s, according to Energy.gov. They 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 to 600 percent) on the coldest winter nights, compared to 175 to 250 percent for air-source heat pumps on cool days.
There are four basic types of ground loop systems. Three of these — horizontal, vertical, and pond/lake — are closed-loop systems. The fourth type of system is the open-loop option. Which one of these is best depends on the climate, soil conditions, available land, and local installation costs at the site.
Mineral, sediment, or dirt contamination sometimes found in open-loop systems, however, are proving problematic for many homeowners in Seacoast New Hampshire, Southern Maine, and Northern Massachusetts, according to Melissa Aho, owner of Ultra Geothermal.
Types of geothermal heat pump systems
— Horizontal installations are generally most cost-effective for residences, particularly for new construction where sufficient land is available. A video on Ultra Geothermal’s Web site shows one installation as a series of five trenches each 100 feet long, 8.5 feet wide and 6 feet deep dug, the heat transfer piping placed at the bottom of each trench.
The pipes are filled with about a 25 percent water-to-ethyl alcohol-water solution that will circulate in the ground and go into the home’s heat pump system. In this case, a forced-air system will provide heating and cooling for the home.
But Darren Rice, Ultra’s geosystem designer and field manager, notes that with a horizontal closed-loop system “you need a tremendous amount of land mass to do a system like this. … If you don’t have an application or a piece of property in which to do this, then your choice would be to go with a drilled vertical closed-loop system.”
— Vertical loops are used when the land area required for horizontal loops would be prohibitive or where the soil is too shallow for trenching. For a vertical system, 6- or 8-inch holes are drilled about 20 feet apart and 150 to 500 feet deep. Into these holes two pipes are inserted that are connected at the bottom with a U-bend to form a loop. The vertical loops are connected with horizontal pipe, placed in trenches, and connected to the heat pump in the building.
The piping “picks up the heat, it is brought inside the house, taken out by the heat pump in the winter, and the reverse happens in the summer,” says John Lovering, whose Gladiola Way home in Dover had an open-loop system that Ultra replaced with a vertical closed-loop system. He narrated another video on the Ultra Web site that chronicles the installation.
Lovering notes that, unlike his old open-loop system, no water is being pumped out of the earth and then being dumped back in. Ultra replaced Lovering’s old geothermal system because it had contaminated his drinking water with excessive iron deposits.