Delmarva Power has asked the Maryland Public Service Commission to authorize an increase in electric delivery rates for the company's nearly 200,000 Maryland customers.

If approved, the change will add 2.8% to monthly residential electric bills, effective 21 July 2011.

The typical bill for a Standard Offer Service residential customer using 1,000kWh a month will increase by $3.76, moving the average monthly bill from $135.26 to $139.02.

The proposed $17.8m increase reflects rising costs required to provide customers with electric service and the factors include upgrades to the electric system to improve reliability and support investment in new technology, the company said.

Delmarva Power provides energy to nearly 500,000 electric delivery customers in Delaware and Maryland and over 121,000 natural gas delivery customers in northern Delaware.