Geothermal in Maine’s challenging climate

Geothermal in Maine’s challenging climate

Mid-Coast Energy Systems has been providing high quality plumbing, heating and air conditioning service to the people of Mid-Coast Maine. Mid-Coast Energy Systems began to host “Geo-nights” informational sessions for consumers. Today, they offer smaller residential and commercial installations in addition to the larger projects. The first and most important step to selling geothermal is education.    

MCES utilized the farm pond by installing a three-ton pond/lake loop exchange system.

WALDOBORO, MAINE — Maine is known for harsh winters and spectacular water frontage. Between the state’s many miles of ocean frontage there are many streams, rivers, tributaries and land locked lakes that substantiate the claim that “you can’t get there from here.”

Bill Morgner, president of Mid-Coast Energy Systems (MCES) recalls that, “I’ve been on service calls where I can literally see my destination across the inlet, but it’s a 40-mile trip to get there without a boat.” 

But for those considering geothermal technology for space heating and cooling, having a body of water nearby can be a very good thing.  In fact, using a pond/lake loop may be the lowest-cost installation option.

Since the company’s inception in 1976, MCES has been providing high quality plumbing, heating and air conditioning service to the people of Mid-Coast Maine.

Today, the company has grown to 34 employees. In 2000, Morgner, along with two other MCES employees, Dave Gamage and Ronald Russell, purchased the company from the original founder. They soon began to install geothermal systems designed exclusively for massive residential or commercial projects.

In 2011, the company was approached by a geothermal distributor who was interested in entering oil-dominated markets with deep heating seasons. As the two companies began working together, MCES managers intensified their geothermal training for estimators and technicians. 

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At the same time, they began to host “Geo-nights” informational sessions for consumers. Today, they offer smaller residential and commercial installations in addition to the larger projects. The first and most important step to selling geothermal is education, according to Morgner. 

“The public seminars are simply to inform, there’s no high-pressure selling,” said Morgner. “Homeowners want to know how a 45°F loop temperature will make their house 70°F. So we share the science behind the technology, show them how the financing works and once they do the math, they’re sold.”

Idyllic setting

In 2013, Tod Brown, a retired physics teacher, attended one of the MCES “Geo-Night” seminars. He and his wife, Merrilee, were looking to cut energy expenses at their circa 1820 farmhouse, located in a country setting complete with farm pond. 

Despite being only 2,350-sq.ft. in size, the drafty farmhouse was an energy hog. 

“We were on a budget payment system with our fuel company, but the expense totaled $4,668 for the year,” said Brown. “In addition, we were using an average of 15,700 kilowatt-hours of electricity annually without any air conditioning.”

The 80-foot-wide body of water needed to be dredged.

Before moving forward with a geothermal installation, the Browns had an energy auditor to provide suggestions about how to tighten up the home, which had been previously insulated with batt and blown insulation. The auditor provided a new heat load calculation and, based on those findings, provided necessary changes. 

The black poly pipe was fused on-shore, floated to the center, and sunk by MCES’ subcontractor, Pine State Well Drilling.

MCES followed the suggestions to determine the appropriate size and design of a new geothermal system and arranged for a general contractor to complete the envelope improvements. They swapped out the furnace for a two-and-a-half-ton, water-to-air unit.  The vertical unit connected easily to the existing ductwork in spite of the low, stone-walled basement. 

Outside, MCES utilized the farm pond by installing a three-ton pond/lake loop exchange system. But first, the 80-foot-wide body of water needed to be dredged. Years of sediment and encroaching cattails had taken a toll on the pond’s water volume. 

Supply and return lines run underground from the building to the water, and are coiled into circles at least eight feet under the surface to prevent freezing. The black poly pipe was fused on-shore, floated to the center, and sunk by MCES’ subcontractor, Pine State Well Drilling. The system was up and running by late summer. All of the mechanical work had been completed before additional insulation was added.

Inaccurate audit

“Our mistake was to believe that the auditor’s report was accurate,” said Morgner. “The insulation contractor had done everything as specified, but when winter came, we learned that our little geo that could … actually couldn’t… Not even with a backup resistance strip.”

Through the winter of 2013/2014, the undersized system maintained adequate indoor temperatures in 5°F outdoor ambient and below, at the expense of the backup resistant strip working overtime. The couple used their propane stove for supplemental heat.  Despite sub-par performance, the homeowners were pleased with the energy improvements. Brown had meticulously tracked his energy expenses throughout the winter. 

“After installing the geothermal system and adding insulation, our electrical use rose to 24,751 kWh, an additional 8,871 kWh for the heat pump in lieu of an oil bill,” said Brown. “We also used $327 in propane for a total of $1,582 for heating, a savings of $3,086.”

Still, Morgner saw room for improvement. In the spring of 2014, he made a company decision to remove the existing heat pump and replace it with a four-ton unit at the company’s expense. 

David Batchelder, AC service technician, preparing to inspect the air filter and the condensate drain on the Brown’s geothermal heat pump.

“It was also apparent that we’d be switching brands on all our geo installs,” said Morgner. “Over the past season, we experienced enough TXV valve and control board problems to justify switching to a different manufacturer. Based on a stellar 40-year relationship with Emerson Swan, we started installing Modine geothermal systems.”

Solid follow through

In the summer of 2014, as promised, Mid-Coast Energy exchanged the units. The first geo unit had barely fit into the cramped basement. Now, at nearly twice the capacity, the new four-ton unit had to be installed as a horizontal configuration.

The transition required a change to all piping in and out of the Modine unit, as well as additional duct work and enlarging existing ductwork. The pond loop was refloated, brought ashore and expanded to the new capacity, then electrical service to the mechanical space was upgraded to support the bigger heat pump.

According to Morgner, the only expense to the Browns was the cost of changing the ductwork necessary to accommodate the horizontal heat pump;  A cost they would have incurred anyway, had the system been properly sized initially.  Aside from that, Morgner said, “we picked up the tab.” 

MCES’ geo installer, Pat Willette, was part of the installation team and reported the new Modine Geothermal unit as “installing easily, despite the switch from vertical to horizontal. The controls were easy to use, too.” 

Another bonus, according to Willette, was the ability to re-use the same twin-tank desuperheater for DHW production. The new unit was ready for a workout by fall of 2014, but the real test was yet to come; Maine’s brutal winter.

Good news

February of 2015 was Maine’s coldest on record. Despite being faced with a record-breaking heating season, the Brown’s new geothermal system performed flawlessly. 

“Our electrical usage amounted to an additional 6,681 kWh over the baseline 15,700 kWh, costing $944 plus $378 for propane for a total of $1,322 for heating, a savings of $3,446 over the baseline,” noted Brown. “This was an improvement over the previous year of nine percent in total electrical usage and a total dollar savings of 72 percent over the baseline!”

The much larger unit proved to use less electricity in a colder winter. According to Morgner, the 10kW electric resistance backup on the smaller unit kicked in when outdoor temperatures neared 20°F. The new Modine unit doesn’t use backup heat until temperatures fall to 5°F.

“To make an exact comparison would be difficult, of course, given what has happened to the cost of oil, but whatever the end result, it’s remarkable,” Brown continued.  “We had great hopes, but this exceeded our wildest dreams! We can’t thank Mid-Coast Energy Systems enough for the time and effort they spent on making our system work as it should, despite the fact that it wasn’t their fault from the beginning.”

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