Farm Uses Waste Cooking Oil to Heat its Greenhouse

Ralph and Lisa Turner of Laughing Stock Farm have a new recipe for salad this winter: Take a vat of used cooking oil from restaurants, strain out food bits ranging from bread crumbs to chicken bones, then use it as fuel to heat a greenhouse.

FREEPORT, Maine — Ralph and Lisa Turner of Laughing Stock Farm have a new recipe for salad this winter: Take a vat of used cooking oil from restaurants, strain out food bits ranging from bread crumbs to chicken bones, then use it as fuel to heat a greenhouse. The result is lush spinach, radishes and other vegetables that the Turners grow in the warm greenhouse and sell to restaurants and stores for Mainers to enjoy all winter long.

"It's pretty easy," Ralph Turner said on Tuesday, standing in the farm's 7,500-square-foot plastic-covered greenhouse, where the thermometer read 79 degrees while temperatures outside were in the 20s.

With the cost of heating oil near $2 a gallon and restaurants happy to have someone take used oil from their Fryolaters for free, Turner believes that more farmers could benefit from utilizing used cooking oil to heat everything from milking parlors to greenhouses.

Even with the cost of labor and materials factored in, he calculates that it costs only about 20 cents to 30 cents a gallon to burn used cooking oil.

If Maine farmers burned the 1.5 million gallons of cooking oil used in the state each year, they could heat 30 acres of greenhouses to grow produce in the winter, Turner said.


"I think it's fantastic," said John Harker, an agriculture development specialist with the Maine Department of Agriculture. "I think it's just what we've needed."

To aid in the greenhouse project, the state awarded Turner an $18,000 competitive grant for farmers who use new technologies that can help save money in the long run.

Turner, who has degrees in mechanical engineering and business, will give a talk on Laughing Stock Farm's use of cooking oil on Jan. 11 at the Maine Agricultural Trades Show at the Augusta Civic Center. On Jan. 15, the Turners will give interested growers a tour of their greenhouse operation at 79 Wardtown Road from 11 a.m. to 2 p.m.

Turner said people sometimes assume he's using biodiesel fuel in his greenhouse project, but that's not what it is. "It's just used cooking oil," he said.

Biodiesel fuel -- the use of which is common in Europe and has been growing in the United States, including Maine -- can be made from used cooking oil but is refined in a process that Turner said involves hazardous chemicals. The oil he uses is not refined.

Biodiesel has been used at places as diverse as L.L Bean -- as fuel for tractor trailers -- and the Chewonki Foundation, a nonprofit educational institution in Wiscasset. The foundation has an ongoing demonstration project on diesel fuel and is helping to investigate whether it's possible to build a biodiesel production facility in Maine, which would use 1 million gallons of used cooking oil per year.

"I think what Ralph Turner is doing is a good idea," said Peter Arnold, coordinator of renewable energy projects at Chewonki. However, he said Turner's method wouldn't work for most people who want an alternative fuel to heat their homes or drive their cars.

"We need it to be instant and simple, and so far what he's doing, although it makes good sense, isn't instant and simple," Arnold said. "He has to work at it."

Turner, who opposes biodiesel fuel that doesn't meet strict standards set by the American Society for Testing and Materials, agrees that used cooking oil isn't suitable for heating homes. But he said it is commercially viable for farmers and greenhouse growers. He believes the data he collects this heating season will demonstrate that.

Turner is using a specially designed waste oil burner donated by Clean Burn of Leola, Pa. The burner allows him to burn unrefined cooking oil. He is working with the manufacturer to develop specifications that can be used to certify the burner is safe and reliable.

Inside the greenhouse on Tuesday, a faint odor like that of roasting meat mingled with the smells of the moist, warm soil sprouting bright green plants. The odor emanated from a 55-gallon open drum of used cooking oil, which looks like a kind of sludgy, brown Crisco.

Turner said he gets his cooking oil from restaurants such as the Harraseeket Inn in Freeport.

The Harraseeket's manager, Glenn Sanokklis, said, "We usually have to pay people to come take it away. What they're doing is even better because they'll come take it away from us. It just saves all around. We believe in recycling everything we can."

Restaurants typically pay between 50 cents and $1 a gallon to have the used cooking oil hauled away. It is rendered down to a grease that is used in animal feed, Turner said.

Turner warms the cooking oil so it is liquid, then strains all of the sediment out of it. He uses it in the burner to heat water that is circulated in pipes throughout the greenhouse. Unit heaters extract the heat and blow it into the greenhouse with fans.

Turner said Mainers use about 450 million gallons of heating oil each year, so the 1.5 million gallons of used cooking oil won't solve the state's energy problems.

However, he said, the greenhouse project "shows one small local solution."

Source: Knight Ridder/Tribune Business News