HALLOWELL — Guests at bed-and-breakfasts probably want to know about the quality of suites and what will be served on their plates, but at Maple Hill Farm Inn in Hallowell, an increasing number are interested in what’s in the basement.

The Hallowell inn and conference center has installed a wood pellet boiler through a Maine company that allows the lodging establishment to pay a flat rate for heating fuel, cheaper than oil, and not pay any upfront costs for the system.

Maple Hill Farm Inn co-owner Scott Cowger, along with representatives for the companies behind the program, gave a tour of the basement and the new wood pellet boiler Wednesday to attendees of an energy policy conference.

Cowger, who owns the inn with his husband, Vincent Hannan, said they probably will save close to $2,000 this heating season with the wood pellet boiler installed earlier this month, but the motivation for switching from heating oil was his and Hannan’s commitment to sustainable business practices.

The inn installed a wind turbine in 2003 and solar panels for electricity and hot water in 2006, and it switched to all LED lighting a couple of years ago, Cowger said.

“This is just part of the puzzle,” he said of the wood pellet boiler.

Even though installing the renewable energy improvements has cost the inn money overall, Cowger said, the inn uses its sustainable practices and various certifications, including being the first certified by the state’s Environmental Leader program for lodging businesses in 2005, as a marketing tool.

“Our guests love it. People are looking to stay in ‘green’ properties,” he said.

Cowger said he’s seen an increase in people seeking out lodging establishments that use sustainable practices. The popularity has been increasing gradually, but he said he’s seen it increase most dramatically in the last four to five years.

Greg Dugal, president and CEO of the Maine Innkeepers Association, said sustainable lodging is still a niche market, but it’s a growing one. Besides energy-efficiency, more guests at lodging places and restaurants are looking for businesses that try to be sustainable by serving local food and minimizing their effect on the environment, he said.

People who try to live their own lives sustainably want to stay at places that have the same standards, Dugal said.

He said guests’ expectations also have grown. Hotels can’t just do things such as post signs saying they don’t wash all the towels every day, Dugal said. They also need to consider the type of detergent they use or ensure the dryers are energy-efficient if they want to market themselves as sustainable, he said.

“It’s much more prevalent in corporate America to look at this stuff. If you have a brand that you try to equate as sustainable, you don’t want to be staying at a place that doesn’t do the same,” Dugal said.

James Knight, CEO of Pelletco, the company that provided the wood pellet boiler to the inn, said he hopes it will lead to people actually seeing value when staying there.

The way Pelletco’s program works, the inn doesn’t own the pellet boiler yet. Customers, mostly larger institutions, typically sign 10-year contracts for Pelletco to provide the pellet boiler and all the pellets needed. The customers pay a fixed rate, which rises with inflation, for the number of British thermal units, or BTUs, needed to heat the buildings.

That way customers don’t have to pay anything upfront to reduce their energy costs, Knight said.

The company buys the Denmark-made pellet boilers from ReVision Heat, which installs pellet boilers, along with heat pumps and natural gas systems. ReVision Heat, a sister company of ReVision Energy, buys the boilers from another ReVision Energy company, Interphase Energy, which brought the boilers from NBE, the Danish manufacturer, to North America, according to Interphase’s website.

After 10 years, the customers can sign another contract with Pelletco or keep the boiler, Knight said.

Nathan LaCroix, general manager of Pelletco, said the company has 15 customers, mostly in Maine. The company also serves Black River Produce in Springfield, Vt., and is installing a pellet boiler in Massachusetts next week, he said.

The goal is to expand throughout New England and build up the other industries that support wood pellet boilers, he said. For instance, he said, the company will be able to cut costs for the businesses delivering the pellets if they can install multiple boilers in a region.

“It’s building the local economy to grow with the industry and building that infrastructure that can actually help supply the smaller places,” LaCroix said.

At Maple Hill Farm, Cowger said, Pelletco’s no-upfront-cost approach allowed his inn to make the switch from heating oil as its primary source.

“The hardest part for us was getting the basement cleaned out,” he said.