Electricity customers in northern and eastern Maine are looking at rate increases of nearly 16 percent next year.

The Maine Public Utilities Commission on Tuesday approved a rate of 8.37 cents per kilowatt-hour as the standard offer for electricity starting Jan. 1 for consumers who live in Emera Maine’s Bangor Hydro District. The current rate is 7.22 cents per kilowatt-hour.

The standard offer is the default price of electricity that customers pay unless they choose a different generator to supply their electricity. About 60 percent of customers served by Emera Maine’s Bangor Hydro District pay the standard offer price. Consumers in Maine are billed separately for power generation and power delivery services.

Electric generation rates for medium-sized businesses will range from 6.7 cents per kilowatt-hour to 14.5 cents per kilowatt-hour. Those rates vary by month.

And large business customers’ rates will also vary and are set in advance each month, based on market prices.

The Bangor Hydro District includes Hancock, Piscataquis and Washington counties and most of Penobscot County, according to Emera Maine’s website.

Other northern Maine electricity suppliers show residential rates that vary from 7.1 cents per kilowatt-hour to nearly 16 cents per kilowatt-hour. These suppliers, known as competitive energy providers, are not regulated by the PUC.

The PUC’s standard offer rate is based on bids received in an auction process. The names of the suppliers will be released in two weeks.

PUC Chairman Mark Vannoy said the increase in the standard offer rate is driven by the natural gas market and that market is constrained in New England because the delivery infrastructure has not increased substantially.

The standard offer for customers within Central Maine Power’s distribution area will be announced Monday.