Mainers looking for alternatives to expensive oil heat have an unexpected option: Propane.

In a rare instance during a Maine winter, the cost of heating with propane is roughly equal to burning oil.

Propane heat typically is more costly than oil, and fewer than 7 percent of Maine homes are warmed by it, according to 2010 census figures. But the run-up in global crude prices has pushed heating oil to new winter records, while the boom in domestic natural gas drilling has stablized and even cut wholesale propane prices.

Natural gas remains way cheaper than oil or propane, and state government is promoting the development of new pipelines for industry in Maine. But natural gas heats only 5 percent of Maine homes and getting distribution lines to a significant number of homes and small businesses could take decades.

Propane heat, on the other hand, can be hooked up almost anywhere, in a day.

These market conditions are evolving just as a controversial proposal to build a large propane storage tank in the port of Searsport is moving forward. Town voters rejected a call earlier this month for a moratorium on the project, which still needs federal and local permits and could face legal challenges.

If built, the 22.7-million-gallon tank would become Maine’s first propane storage facility able to hold more than a week’s worth of winter capacity. Having a robust, instate supply could help temper prices and feed growing demand.

“Propane has been the growth market for my members,” said Jamie Py, executive director of the Maine Energy Marketers Association.

Most of the trade group’s 180 retail members sell both fuel oil and propane. Seven out of 10 Maine homes still use oil, but oil sales are declining, Py said, as people weatherize and offset their heating needs with less-costly fuels, such as wood pellets and cordwood.

Some homeowners have installed propane-fired fireplaces for looks and to warm a room. Central heat has been less common, but that’s changing with the recent split between oil and gas prices.

“We’re starting to see the first separation of propane and crude oil prices,” said Joe Rose, president of the Propane Gas Association of New England. “We expect to see that trend continue.”

Crude oil prices have been rising this year, which is one reason heating oil and gasoline are up. Natural gas, by comparison, remains very low.

Propane, or liquefied petroleum gas, as it’s sometimes known, is a byproduct of oil and gas production. Propane prices typically follow crude oil, but today, they’re tracking natural gas. That’s because drilling in shale rock deposits is yielding a “wet” natural gas containing liquids that are refined into propane, butane and other components. By some estimates, more than 60 percent of domestic propane is coming from gas deposits.

Energy prices are unpredictable, of course. But for the current heating season, average residential retail prices for propane have remained stable, at $2.87 a gallon, while heating oil is up roughly 28 cents over last year to $4.10 a gallon, the U.S. Energy Information Administration says.

Propane and heating oil displayed a similar, although brief, inversion in 2008, when global oil prices surged to record levels prior to the recession. Oil’s advantage resumed a year later, when demand fell in the economic downturn and prices plummeted.

For a homeowner with an older oil furnace, today’s trend presents an opportunity for comparison shopping.

In Maine, the average statewide price for heating oil last week was $3.86 a gallon. The average price for propane used in space heating was $3.15 a gallon.

Propane contains less heat energy than oil, however, so comparing only prices isn’t enough. The other part of the heat equation is burner efficiency.

Modern condensing gas boilers boast efficiency ratings above 95 percent. An older oil furnace might be 75 percent efficient. At these rates, burning propane would cost roughly the same as oil. Propane’s price parity would fade if compared to a top-efficiency oil burner, in the 90 percent range, assuming the spread between oil and propane continues over time.

But propane has other benefits that dealers are promoting. It’s a cleaner fuel that requires less burner maintenance. It also can be used for cooking, drying clothes and heating water.

Amortizing the cost of a new heater is a factor, though. Gas boilers that also heat tap water cost between $5,000 and $10,000, installed. Another option is a direct-vent space heater, such as those made by Rinnai. They run between $1,000 and $2,000.

If propane is to gain traction in Maine, supply problems will need to be solved.

Maine currently burns more than 100 million gallons a year of propane. Most of it arrives by rail from western Canada. Smaller amounts come by ship to a 25-million-gallon tank farm in Newington, N.H., and are trucked north. Some Maine dealers have onsite storage, but their capacities are limited.

Maine nearly ran out of propane in the winter of 2007, during a strike by Canadian railroad workers. That led to an effort to site a large storage tank in Maine.

The Searsport project is being proposed by Denver-based DCP Midstream, which is jointly owned by Spectra Energy and ConocoPhillips. The tank is sized to hold the contents of a cargo ship, typically 15 million gallons. The terminal, which is also served by rail, would receive a half-dozen ships a year, according to John Pratt, director of Northeast sales for DCP Midstream.

The ships are likely to come from Europe, Pratt said, loaded with North Sea gas. Propane is transported in refrigerated vessels and kept in a liquid state.

DCP Midstream still needs permits from the U.S. Army Corps of Engineers and the town. Tank opponents, who have concerns including safety, truck traffic and the scale of the 14-story tank, may continue their challenge. If the company can clear these and other hurdles, construction will take 18 months, according to Pratt. That would put operation at least two winters away.

A propane storage tank in Maine also would make the state less vulnerable to price volatility created by high winter demand and dependence on rail delivery. It takes two weeks for a rail car to travel from western Canada to Maine, Pratt said.

“What the tank should do is stablize prices,” he said.

Staff Writer Tux Turkel can be contacted at 791-6462 or

tturkel@pressherald.com