SOMERSET, Mass. — The Brayton Point Power Station, an aging coal plant that has become a subject of political controversy and regulatory debate, will shut down in June 2017. A letter to ISO New England from David Freysinger, executive vice president of coal operations at EquiPower Resources, announced the decision this week.

To prevent power lines from overheating, ISO New England urged EquiPower Resources last month to keep Brayton Point open. ISO New England works to maintain a reliable electricity supply throughout the region, and although ISO New England is unable to compel power plants to stay open, its letter recommended caution.

But further correspondence has led to another solution. An email recently reprinted in the Boston Business Journal said transmission improvements may prevent power lines from overheating by 2016, allowing the coal plant to close safely the following year.

In 2013, facing financial difficulties, EquiPower Resources announced its interest in closing the power plant. It had recently bought Brayton Point from Dominion Power. Keeping coal plants open in Massachusetts has become relatively expensive compared to the lower cost of operating natural gas plants.

In fact, New England is becoming highly reliant on natural gas. According to Forbes, 52 percent of the region’s electricity came from natural gas last year.

Natural gas dependence, however, can cause economic hardship during the winter. Natural gas pipeline capacity is limited, and gas provides both heat and electricity. Therefore, winter prices can become volatile due to supply shortages. During the cold snap this January, electricity prices have varied from $40 to more than $200 per megawatt-hour.

Also, the state’s residential fuel-assistance funds have been exhausted early this season because of the high cost of heating homes, according to a recent article in The Boston Globe. The program is now seeking a boost in aid.

ISO New England is working on developing a strategy to diversify the region’s fuels to reduce natural gas dependence, according to the company’s media contact, Lacey Ryan.

The Interstate Reliability Project, which is designed to improve the reliability of the grid in New England, will help to ensure that energy will flow through the grid safely after Brayton Point is retired.

Some environmental organizations have been eager to see the coal plant close, and several protests have been held in the past few years.

“Retiring Brayton Point on schedule is good news for public health and the climate,” said James McCaffrey, senior New England campaign representative for the Sierra Club’s Beyond Coal Campaign. “Clearly, the era of dirty, polluting coal power is coming to end in New England. However, the knee-jerk reaction by our governors to switch from one dirty fuel to another puts families at risk from more extreme weather, harmful pollution and volatile energy prices. As the region’s remaining coal plants retire, we have a tremendous opportunity to build a modern energy infrastructure with clean, reliable and affordable wind and solar power.”

Despite installing emissions controls, Brayton Point still tops the list of sources of toxic releases in Massachusetts because of its generation of mercury, arsenic, lead and ammonia, according to the Conservation Law Foundation.

The state’s Global Warming Solutions Act is one of the driving forces behind the move toward closing coal plants and reducing fossil-fuel dependence in Massachusetts. However, the legislation lacks regulatory power. Criteria for enforcing it have not yet been put into place. Once these criteria are in place, they may change the landscape of energy use in the state considerably.

Once Brayton Point closes, Somerset may seek redevelopment opportunities for the property to maintain its tax base. The coal plant also employs some 200 people.