RAYMOND – Les Otten, in his excellent article about pellet heating systems in the March 5 issue of the Portland Press Herald (“Wood pellets can help with oil crunch, says industry entrepreneur”), correctly observed that pellets are naturally available in Maine, and that pellet heating is lower cost than other fossil fuel options.

He also claimed that pellet heating is half the cost of electric heat, which is not necessarily true. Only with electric resistance heaters is that statement accurate.

In fact, when electricity is used in ground source heat pumps, pellet heat is not half the cost of “electric” heat, but actually twice the cost of electrical pump heat. That’s because ground source heat pumps require only 1 unit of electricity to produce about 4 units of heat to the home. Further, most of the heat supplied by these heat pumps comes for free from a continual supply of clean, renewable solar energy stored in the ground every day.

Sometimes called “geothermal” heat, this infinite source of thermal energy stored in the ground is indeed the “sleeping giant” of low-cost, clean heating available in Maine.

Some detractors claim that although geothermal heat is indeed the least expensive heat in Maine, it is more expensive to install. However, when geothermal installations are financed, rather than being paid for as a lump sum up front, it can be shown that homeowners start saving money the very first day when they turn on their heat pump.

As Mr. Otten points out, northern Europe is way ahead of the United States in terms of smart approaches to heating. In addition to pellet stoves and boilers, ground source heat pumps have been installed in Europe for many years. In fact, currently in Sweden, 85 percent of all new home construction uses ground source heat pumps for home heating. The remaining 15 percent of new homes are in communities with centralized district heating, using biofuel. Smart Swedes have no dependence on foreign oil for their domestic heating, something they started planning for in the 1980s.

Geothermal heat pumps’ low- cost heat is one of the best-kept secrets in Maine. In fact, installation of these systems started in the Bangor area in the 1970s. Every time there has been a spike in oil prices, there was a blip in heat pump installations in Maine. This happened in the ’70s, the ’80s, the ’90s, and again in the early 2000s. In 2008, when oil costs took off, heat pump installations increased by some 400 percent, but eased off somewhat as oil prices subsided. However, the federal 30 percent tax rebate for geothermal installations from 2009 through 2016 has kept the growth of heat pump installations alive. Indeed, an exponential growth can be expected this time around, rather than a short-lived blip.

The predominant form of ground coupling for geothermal systems in Maine is by means of a drilled well. Many times the same private well is used by homeowners for their own domestic water. Maine’s distributed settlements without town water, its geology, and its overdependence on heating oil make ground source heat pump heating systems ideally suited to the state.

For new residential construction, as in Sweden, geothermal systems should be the lowest-cost heating technology of choice. Also, for existing dwellings, the following favorable set of statistics applies:

• Currently 80 percent of Maine residences heat by oil. This provides a huge potential geothermal retrofit market.

• 70 percent of residences are owner-occupied, giving great incentives to invest in low-cost heat.

• 50 percent of residences already have their own well for domestic water. Hence, they may have the ground coupling part of their geothermal system already available, and paid for.

• The average cost of oil in Maine is $3.65 per gallon. Compare this to geothermal heat, with electricity at 15 cents/kwhr, which would provide the same amount of heat to the home as would oil at about 93 cents per gallon.

As in 2008, there is now clearly a high motivation to switch from oil to geothermal heat pumps, simultaneously cutting heating bills by about 75 percent — a huge saving by any measure.

The message for Mainers is: Let’s be as smart as the Swedes and use heat pumps to wean ourselves forever from foreign heating oil.

— Special to the Press Herald