"Are those french fries I smell?" Michael Hatton has heard the joke before but still smiles anyway.

"Are those french fries I smell?" Michael Hatton has heard the joke before but still smiles anyway. No, it doesn’t smell like that at all, he says as he mixes and pumps biodiesel fuel into a

Dunlap’s Energy delivery truck on a blustery winter’s day.

In fact, the scent and appearance of the fuel are no different from the regular home-heating oil he has sold in the past. This mixture, though, contains 20-percent recycled cooking oil from restaurants, which may have used it for cooking french fries at one time.

Biodiesel is cleaner, safer and helps lower the carbon footprint for homeowners, according to Hatton, Dunlap’s Energy vice president. Called Bioheat Fuel, it is a blend of ultra-low sulfur heating oil and vegetable oil, which is mostly made of soy.

"It’s the same price per gallon and it’s the only fuel with a renewable component," Hatton says. "It lowers greenhouse gases and equipment lasts longer because it burns cleaner."

Dunlap’s Energy began pumping the new biodiesel mixture last year following construction of a special mixing tank at the company’s production facility on Holman Road, located just off Long Pond Road near Exit 5 on Route 3. A $228,250 grant from the Massachusetts Department of Energy Resources helped pay for the project.

The company opted to switch to biodiesel fuel because of an oil industry initiative to reduce greenhouse gas emissions to a net-zero level by 2050. Across the Northeast, many heating oil retailers are selling blends of 20 percent or more of biofuel. Studies suggest this effort can lead to a dramatic drop in emissions.

"Our customers seem pleased," says Melanie Logan, Dunlap’s Energy plant manager and Hatton’s sister. "We’ve received a lot of encouraging phone calls from people who say they are happy we are doing this."

Other companies in the region are selling biodiesel mixtures to local homeowners. However, Dunlap’s Energy is the only one in Plymouth with a mixing plant. A computerized system blends the vegetable oil with heating fuel as it loaded on the truck for delivery.

"We keep the biodiesel in a separate tank because its viscosity is very thick," Hatton says. "It doesn’t get mixed with the heating oil until it goes on the truck. Once it is blended, it doesn’t separate." He added, "We haven’t had any issues with serviceability. It works well in all oil-heating systems."

The Plymouth Area Chamber of Commerce assisted Dunlap’s Energy with its application for the DOER grant. Executive Director Amy Naples says the family-owned and -operated business has been an important part of the community for more than 80 years, supporting several local nonprofit organizations, veteran programs and local youth sports teams.

"This investment benefits our local economy," she said. "We support the development of all local renewable energy, especially when keeping energy dollars in our local economy, as well as creating and maintaining jobs. Dunlap’s Energy is providing clean and reliable biofuel and is committed to making a large economic and environmental impact in our region."

For more information about Bioheat Fuel, contact Dunlap’s Energy at 508-746-1278 or melanie@dunlapsenergy.com, or visit www.dunlapsenergy.com.