Hot Savings

In the fight against climbing utility bills, more Maryland homeowners are turning to geothermal heat and air conditioning for relief

May 18, 2008|By Andrea F. Siegel | Andrea F. Siegel,sun reporter

The grinding noise of drilling two 400-foot-deep holes in the ground was ear-splitting, never mind the toll the job was taking on the front lawn.

But Monica and Dave Borle leaned over the railing outside the front door of their Pasadena home on a sunny April morning as though they couldn't get close enough to the red flatbed truck with its generator and derrick. Their focus was less on the loud drama and more on what this mess promises: eco-friendly, efficient energy with a financial reward.

They're switching to geothermal heat and air conditioning.

"It's the right thing to do," said computer scientist Dave Borle.

Last summer, having already applied most of the routine energy-saving techniques in their home, they sweated through electric bills topping $450 a month for their all-electric 2,400-square-foot house. Grimacing at the prospect of monthly electric bills approaching $600 this summer, the couple researched alternative energy methods. Their conclusion: Use Mother Earth's constant temperature of about 56 degrees to heat and air-condition their house.

An estimated 2,500 or so Maryland homes have geothermal systems, from condos in Ocean City to expansive homes in Harford County.

Skyrocketing home air-conditioning and heating costs, and notably electric rates and fossil fuels, have ignited homeowner interest in the past two years - so much that some well-drillers are finding geo-exchange projects are the mainstay of their work.

The potential energy savings are typically greater than loan repayment for retrofitting or what's added to a mortgage.

"You can look at numbers between 60 and 70 percent of your heating and cooling," said Dustin Owens, sales manager for Owens Comfort Systems, a Bowie-based heating and cooling company, which outfitted the Borles' home.

The most disruptive part of the transition was boring into the ground for two 800-foot-long pipe loops that conduct the ground's heat, work that took a little more than a day. Ensuing work completed this month connected the loops, through pipes laid in trenches, to a specialized heat pump inside the house. The Borles' home already had the forced-air vents.

The Borles aren't terribly concerned about the appearance this spring of the front yard.

"It's grass, it'll grow back," Monica Borle said with a shrug.

Besides, she said, much of the front yard has other landscaping that was untouched. The couple prefer to take this long-term perspective: They are making a $22,000 investment in their home now. They will start to realize utility bills cut by about half. They'll recoup that upfront outlay, depending on their thermostat settings and utility rates, in 10 years at the outside, but most likely sooner.

"Everything else after that is gravy," she said.

Part of that gravy could flow from the state. Come July 1, the Maryland Energy Administration maximum grant to a homeowner for installing a geothermal system will rise from $1,000 to $3,000, and jump to $10,000 for a commercial use. Officials expect the number of applications for the $591,000 cash pool that is to be shared with grants for solar-energy systems to continue to climb.

"It will go quickly," said David Cronin, MEA assistant director for renewable resources.

The centuries-old basics of the technology rely on exchanging heat and cold. Water in the pipes naturally transfers heat more efficiently than air does, said Toni Boyd, assistant director of the Geo Heat Center at the Oregon Institute of Technology in Klamath Falls, Ore.

In a closed-loop system, the type used in Maryland, hundreds of feet of pipes circulate a blend of water and often alcohol (sometimes refrigerant), extracting warmth from the ground in the winter. The pipes connect to the heating and cooling system in the house.

A heat pump inside uses the network for a forced-air system that warms the home's air. That's reversed for summer air conditioning, when the home's heat literally gets returned to the ground in an environmentally important exchange, Boyd said.

Based on home size and other factors, heating businesses determine the size of the systems needed inside and outside. Well-drillers site the narrow shafts for the vertical pipe loops and the trenches bringing them into the house, based on geological maps, other utilities, well requirements, and state and local government codes.

Short of extensive property that allows burying Slinky-like pipes close to the surface, vertical is the way to go, whether through mud, sand, rock or water, experts say. Each vertical pipe is a long and narrow U-shape.

That has allowed geothermal systems on rowhouse lots, said Brad Rogers, an owner of Baltimore Green Construction and related companies, who expects to install one in the renovation of a Charles Village rowhouse this summer.

"If you can fit a delivery truck into the area, you can go geo," said Adam Santry, vice president of Allied Geo-Systems, the Baltimore well-drilling company that did the Borles' bores.

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