Electric rates will drop on Sept. 1 for Dominion Energy residential customers.

The typical 1,000 kilowatt-hour residential monthly bill will drop by $1.55 starting Friday, due largely to a $2.07 reduction in transmission-related costs. While the company is still upgrading and modernizing its transmission system, transmission-related costs assigned to residential customers declined versus the previous year.

The decrease means Dominion Energy’s typical monthly residential bill is 7 percent below the Virginia average and 15.9 percent below the national average, according to a company press release.

The reduced rate is the result of adjustments in the portion of customer rates supporting the transmission system, as well as other bill modifications approved by the Virginia State Corporation Commission effective Sept. 1.

The net impact of the changes for the monthly bill for the typical Dominion Energy residential customer is a decrease of 1.1-percent, lowering the typical bill from $117.20 to $115.65.