National Grid has proposed a 21 percent increase in current electricity rates for this coming winter season.

By: LINDA BOCK |

National Grid recently filed on Tuesday with the Massachusetts Department of Public Utilities and electric customers will see a significant increase in their bills due to higher power supply prices.

National Grid asked for a 21 percent increase in current electricity rates.

If approved, starting in November, the electric supply price for Massachusetts residential electric customers will be 13.1 cents per kilowatt hour. As a result of these market prices, a typical residential customer would see an electric bill that is 21 percent higher than their current bill and 9 percent lower than last winter’s bill (when accounting for additional bill adjustments made throughout the year), the company posted on its website.

The typical residential customer’s monthly bill starting Nov. 1 will be $110.18, compared with a current bill of $90.82 or November 2014 bill of $121.20.

Due to continued gas pipeline constraints, the electric supply prices remain volatile and relatively high, though not as high as last winter, according to National Grid.

“National Grid remains concerned about volatile and unpredictable electricity supply prices our customers are subject to,” said Marcy Reed, president of National Grid in Massachusetts in a statement. “We urge Massachusetts residents to take full advantage of energy efficiency tips and other solutions such as payment programs that can help stabilize their bills.”

The new electric supply prices will be in effect from November through April versus the current prices in place from May through October. The section of the electric bill where customers will see the difference is called Supply Services. This section of the bill represents the cost of the electricity the company purchases on behalf of customers and passes on without a markup. This winter’s price represents a 41 percent increase from the current residential electric supply price and a 19 percent decrease from last winter’s price.

National Grid does not generate electricity and plays no role in determining market prices; the company delivers electricity to the homes and businesses of customers, according to company officials.