Heating oil now being delivered to homes and businesses across Maine will burn cleaner than ever before, cutting boiler maintenance costs and fuel use while improving air quality and visibility, according to industry and state environmental officials.

After years of planning, Maine switched on July 1 to ultra-low sulfur heating oil, a fuel that studies show can burn as cleanly as natural gas. With 99 percent less sulfur, the new oil will improve performance in existing equipment, while also being able to fire the next generation of high-efficiency boilers coming on the market.

These developments may give dealers welcome talking points in their attempt to preserve oil’s shrinking role as Maine’s dominant heating fuel, and slow customer conversions to gas, propane and electric heat pumps.

“We needed to do this to be competitive, to be the cleanest we could be,” said Jamie Py, president of the Maine Energy Marketers Association. “It took a lot of legwork to force refiners to do this, but consumers are demanding cleaner and better fuel.”

Maine homes and businesses burned more than 290 million gallons of heating oil in 2016, according to the Maine Department of Environmental Protection. Oil use has been falling, with better-insulated homes and people shifting to other fuels that have more-stable prices. But six in 10 Maine homes still burn oil, according to the federal Energy Information Administration. That’s the highest concentration in the country.

Among the drawbacks of heating oil is that combustion produces sulfur dioxide, a gas that irritates the throat and lungs. Small particles also go up the flue and contribute to regional air pollution. Inside the boiler or furnace, sulfur oxides coat heat exchangers, reducing efficiency and requiring regular cleanings by a technician. For these reasons, states in the Northeast, where heating oil is most common, have been pushing to cut sulfur content.



The transition to ultra-low sulfur has been underway for years.

New York, the region’s biggest oil market, switched in 2012. Most of the New England states began moving in 2014 from oil with an average of 2,000 parts per million of sulfur to 500 ppm, a blend called low sulfur. Maine skipped the phase down and went straight from 2,000 ppm high-sulfur oil last year to the new ultra-low standard of 15 ppm. It had passed a law in 2010 mandating the 15 ppm, but gave the industry until 2018 to phase out the higher levels.

Besides cutting sulfur dioxide emission by 99 percent, the new fuel also reduces particulate emissions to near zero. That’s on par with burning natural gas.

These emission values were confirmed in studies funded by the New York State Energy Research and Development Authority and Brookhaven National Laboratory. Any oil delivered in Maine since July meets the new standard.

Prior studies at Brookhaven also showed that heat exchanger corrosion and fouling was greatly reduced with ultra-low sulfur oil. The New York studies estimated that homes and businesses would save between $54 million and $108 million a year in annual cleaning costs for heat exchangers, because they didn’t need service every year. Because the heat exchangers could transfer warmth more efficiently throughout the winter, field studies also found that boilers burned less oil.


One unexpected downside discovered in New York was that the new oil shortened the life of some oil burner pump seals, a finding that the industry is evaluating.

But overall, the state agency concluded, ultra-low sulfur now makes heating oil “an environmentally attractive option” that’s comparable to natural gas. It also noted the added benefit of blending with 5 percent vegetable oil, a mix known as biofuel that’s now widely available in the Northeast.

The New York agency concluded: “… the use of ULS heating oil blended with biofuel can reduce the global warming potential of home heating oil lower than any other home heating fuel. However, many homeowners and fuel marketers and service technicians are not aware of these recent findings.”


Maine oil dealers are trying to get the word out with a $100,000 awareness campaign that includes news releases and TV commercials. Some dealers will include information cards in customer bills with a web link for more information. The headline reads:

“New ultra-low sulfur home heating oil is cleaner, more efficient and more environmentally friendly. The best part of all? It’s already in your tank.”


Py, the energy marketers head, said his group appreciates the New York studies, but wants to be conservative about making claims for Maine customers.

For instance: The New York agency suggested some heat exchangers won’t need to be cleaned for five to seven years.

But Py noted that other maintenance issues can arise, so regular heating system inspections remain important. A burner cleaning in Maine can cost between $100 and $225, dealers say.

The New York demonstration also cited fuel savings of 11 percent and 12 percent in a couple of homes. In Maine, a typical home burns 700 gallons a year. With oil prices in Portland today at roughly $2.80 a gallon, that would translate into $215 of savings. But Py said he’d rather not estimate fuel savings.

“We’re just saying, because your heat exchanger works better, you could save a bunch of gallons,” he said.

The switch to the ultra-low sulfur product is not expected to affect oil prices as they fluctuate with demand throughout the year.


As promotions for the new oil continue, dealer Charlie Burnham of Charlie Burnham Energy and Heating Services in Freeport, said he’s excited about oil boilers that can rival the efficiency of new gas burners.

Until now, high sulfur content prevented heating oil from being used in so-called condensing boilers, which recover heat in exhaust gases. New oil-fired condensing boilers can achieve a peak operating efficiency of greater than 90 percent, according to the federal Energy Star rating program.

Some of those models are being sold now, and Burnham said more are coming. Some recover enough heat that they can be vented through sidewall plastic pipes, eliminating the need for a chimney.

“My advice is to wait for the first of the year,” he said. “There’s a new generation of equipment coming out and oil will be able to do condensing without any problems.”

The Maine DEP estimates that the new fuel will reduce sulfur dioxide emissions by roughly 1,300 tons a year. That will improve Maine’s winter air quality, the agency said, and improve visibility in priority areas covered by the federal Clean Air Act, such as Acadia National Park and Moosehorn National Wildlife Refuge.

But Marc Cone, director of the DEP’s air quality bureau, said sulfur dioxide levels in Maine already are quite low, roughly 11,000 tons a year. The biggest benefit Cone said he sees is giving rural residents who live far from natural gas lines a better heating option.


“Not everyone has gas available,” he said. “So it’s a good thing for consumers to have this fuel.”

Tux Turkel can be contacted at 791-6462 or

[email protected]

Twitter: TuxTurkel

This story was updated at noon on Oct. 11, 2018, to correct the amount of oil used by Mainers in 2016.

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