BOSTON (AP) — The state’s highest court Thursday reduced penalties imposed against two electric utilities for their response to a pair of 2011 storms, but upheld the standard used by Massachusetts regulators in evaluating how the companies performed after widespread power outages.

The Department of Public Utilities fined National Grid $18.7 million for its response to the outages caused by Tropical Storm Irene in August 2011 and by a rare October snowstorm. NStar was fined $4.1 million for the two storms and a third utility, Western Massachusetts Electric Co., was fined $2 million for the snowstorm only.