BELFAST, Maine -&nbspThe recently approved increase in the price of electricity comes at a time when businesses and institutions around the state already are struggling with the growing cost of energy.

The Maine Public Utilities Commission on Tuesday approved rate increases for medium and large customers of Bangor Hydro-Electric Co. and Central Maine Power Co.

Medium business customers of CMP will see an increase of 23 percent starting Sept. 1, and large customers will see an increase of 32 percent. For Bangor Hydro, medium customers will see a 21 percent increase while large users will see an increase of just under 20 percent.

The increase applies to the cost of electricity, not its transmission.

Utilities classify Maine businesses as small, medium or large depending on the amount of electricity they demand at peak periods, according to the PUC.

“We are considered a major user of electricity and we’ re also a major user of oil,” said Mark Biscone, executive director of Waldo County General Hospital in Belfast. “We’ re dealing with increases in the cost of food as well, so it is a concern to the hospital — everyone who works here and the general public as well,” he said Thursday. “We’ re concerned as everyone else is, both with fuel oil and electricity.”

Biscone said the hospital is studying the potential of investing in a biomass boiler that would use wood chips to provide its energy needs. He said finding a steady supply of chips could prove difficult because the demand for that product is also rising.

At Penobscot McCrum, a potato processing company in Belfast, owner Jay McCrum estimated that a 20 percent increase in the cost of electricity would boost his monthly electric bill by $25,000. McCrum said the increase would be a major problem for the company but that he was committed to the business and the state. The company spends about $100,000 to $105,000 monthly on electricity and transmission costs, he said.

“It’ s a pretty tough business environment out here, but we’ re going along and continuing to grow the business,” McCrum said. “As a family, we’ re proud to live in the state of Maine but it’ s certainly got its challenges. Down the road I hope state government will recognize that. Sometimes it’ s a real challenge.”

At GAC Chemical in Searsport, General Manager David Coulter said the plant’ s electrical contract was scheduled to expire at the end of the year and that the rate increase should have some influence on the negotiated price of its next contract. The cost of oil is more troubling, he said, as the company’ s machinery is driven by steam from its boilers.

“It will affect us at some point but right now we are locked in with an alternative energy supplier that will expire at the end of the year,” Coulter said. “Electricity is not a large component of our business. What is important to us is oil. We’ re keeping our fingers crossed but we’ re not overly hopeful.”

Penobscot Bay Medical Center in Rockport also has turned to the open market for its electricity needs.

Chief Operating Office Eric Waters said the hospital was locked in until December. He said when it comes time to negotiate a new contract, the Maine price increase likely would result in corresponding higher costs from outside providers as they deliver their power along CMP transmission lines.

“What’ s happening doesn’ t really impact us at this point,” Waters said. “The impact it will have on us will occur in January, so it’ s really just a delaying effect. It’ s the same with oil where we’ re locked and have a very good rate that will get us to the end of our fiscal year. When you buy on the market, [the price] literally moves daily. We’ re at the mercy of the market when it comes to powering the boilers at the hospital.”