Here’s how the geothermal system works at Gorham Middle School. Water mixed with antifreeze is pumped through a series of connected 1 1/2-inch pipes in 116 holes bored 425 feet in the earth under a school athletic field. Paul Roney, facilities manager for Gorham schools, said the system has 15 miles of pipe.

Roney said the solution is warmed by the ground to a temperature of between 40 and 50 degrees, depending on the season. The solution is pumped into a mechanical room, where it is compressed, generating additional heat. The solution is circulated through heat pumps located in classrooms and corridors with temperatures throughout the building controlled from Roney’s office. Roney said the only other cost is basically for electricity.

There is no backup boiler.

A prototype geothermal heating and cooling system at five-year-old Gorham Middle School is generating interest around the state – and some controversy.

At issue is whether the system is the money-saver it was touted to be, important because similar systems are slated for new schools in Westbrook and Gorham.

Pointing to an independent study prepared in 2006 for the Maine Department of Education, Gorham school officials said last week the geothermal system is saving money.

“We’re pleased with it,” said Superintendent Ted Sharp, adding that Gorham taxpayers are reaping the benefits.

However, the question of whether geothermal systems are more efficient remains a matter of debate for some engineers. Anthony Lisa Jr., a retired consulting engineer who lives in Cumberland, has been questioning publicly whether geothermal systems are worth the additional cost of installing them.

“Gorham Middle School is not saving money on monthly energy bills,” Lisa said this week.

The state is remaining cautious about supporting new geothermal systems in schools, leaving most of the cost of installing the systems in schools up to local taxpayers, according to Scott Brown, school construction coordinator at the Maine Department of Education.

Brown said he was reluctant even to comment on geothermal systems because of the controversy surrounding them, but he did say he believes the geothermal system at the Gorham Middle School was working well. He said geothermal systems are part of plans for new schools in Ellsworth, Westbrook and Brunswick.

According figures Lisa says he obtained from the Maine School Management Association, for the 2006-2007 school year, Gorham Middle School paid $31,191 more for energy than Lincolnville Central School and $40,667 more than Hall-Dale Elementary School – both non-geothermal schools.

Lisa’s analysis of Gorham’s geothermal energy plant aired in a critical TV news report last month that drew some heat at the December Gorham Town Council meeting. This week, Matt Robinson, chairman of the Town Council, said he believes the geothermal system is working and is trusting people the town has hired.

“We haven’t been led astray,” Robinson said.

Lisa, who says he’s been working as a consulting engineer with schools for 35 to 40 years, conducted and paid for a study of energy usage in more than 100 schools four years ago. He distributed results to superintendents as a benchmark to prioritize energy conservation measures.

However, Lyndon Keck of PDT Architects, who designed Gorham Middle School, said a separate 2006 independent study, conducted for the Department of Education, concluded the Gorham Middle School system saved money when compared to Gorham High School, other average existing schools, and projections for modern schools under construction.

That report said actual data from Gorham Middle School in its first two years resulted in energy consumption 38 percent less than the average projections for five non-geothermal, new schools. But the report indicated energy cost savings of only 6 percent less, representing $10,200 per year.

Keck said total energy cost at the middle school last year was $1.25 per square foot compared to $1.67 at Gorham High School, which is about equal in size. Unlike the middle school, the high school is not fully air-conditioned. The original high school building opened in 1959 and was renovated in 1992.

The total energy cost for the High School last year was $230,881, and the the energy cost at the middle school was $172,947, according to Hollis Cobb, the finance officer at the Gorham School Department.

Lisa said he wrote a letter to Gov. John Baldacci earlier this year

requesting that the independent study done in 2006 be updated, since heating bills from new schools built without geothermal energy were available. The study had been done using projected costs for schools under construction.

Keck said Lisa’s comparisons of Gorham Middle School with two elementary schools was inappropriate. Geothermal, Keck said Tuesday, is absolutely saving Gorham money using real utility bills.

In 2001, when the middle school was designed, Keck said, the Gorham Building Committee was interested in conserving energy. He said the middle school was ahead of its time.

“Bravo for Gorham, they were ahead of the curve,” Keck said.

According to figures in the 2006 study, the geothermal system installed at Gorham Middle School cost nearly $2 million, including $600,000 for the holes bored in the earth. A traditional heating and cooling system would have cost $1.3 million.

Keck said annual maintenance for the geothermal system is $13,400 compared to $14,100 estimated for a traditional system.

Jim Hager, a member of Gorham School Committee who was chairman of the middle school building committee, last week praised the geothermal system.

“It’s been a huge success by any standards,” Hager said. “As a taxpayer, I wanted to ensure we had a good, long-term investment.”

Gorham will also install a geothermal system in its new elementary school. Hager said the new school is in the design phase with construction due to start this summer.

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