AUGUSTA (AP) – With prices for fuel oil and firewood rising, some Mainers are turning to coal as a source of cheap energy.

Maine has only a handful of dealers left who sell coal, whose popularity as a heating fuel has been on the downslide since the introduction of central heating a century ago. Coal use hit rock bottom in the 1990s, when a glut of cheap oil hit the market.

But of those Mainers who still use it, coal remains most popular on the islands because it’s easier and cheaper than wood to deliver. Some fishermen choose coal over wood because they can leave home all day and let a coal fire keep burning by itself.

Anthracite is the highest grade of coal. It produces more heat per dollar than wood, wood pellets, propane, natural gas, electricity or fuel oil. In today’s market, $9 of coal produces as much heat as $12 of seasoned wood and $15 of fuel oil.

Bill Clarke, who supplements his oil-fired furnace with coal to heat his historic Yarmouth home, said his coal stove reduces his total heating bill by about $100 a month.

“It doesn’t replace oil, but augments it,” said Clarke. “It helps us get through the winter.”

Jerry Sullivan, owner of Rings Coal & Oil in Yarmouth, fires up his coal furnace in the fall and keeps it going all winter. Sullivan said people who consider coal dirty are thinking of soft coal that power plants burn. Sullivan claims that anthracite coal is cleaner than wood and contains less sulfur than oil.

Damariscotta Hardware sells about 400 tons of coal a year, said owner Rob Gardiner, who has been getting more questions from his customers lately about coal. While he says it produces a fire that doesn’t need constant tending, he said it is not for everyone because the fine coal ash needs to be removed every day.

While oil is more convenient than coal to use for heat, some coal users say oil doesn’t do as good a job on the coldest winter days.

Rob Gillies of Yarmouth also says coal supplies are more dependable than wood and the quality is more consistent. Also, coal doesn’t have to be stacked or split, he says. And Gilles wife, Kat, like the way coal looks when it burns down.

“It makes a peaceful, more serene atmosphere,” she says.