Delmarva Power is asking state utility regulators for permission to build a liquefied natural gas storage facility in northern Delaware.

The tanks would serve as backup when demand is highest during the coldest days of the year. Currently extra fuel is piped in from other states, which can be costly.

The utility said construction and operation of the storage facility would save Delmarva customers an estimated $124 million over 30 years.

According to a docket filing last week, the facility would be built on property near Red Lion that is already home to a Delmarva Power substation and a Bloom Energy fuel cell generation facility.

Delmarva is proposing to build five 100,000-gallon gas storage tanks, with the possibility of adding five more to meet future customer demands.

Delmarva says the facility would improve the reliability of its natural gas supply and distribution operations and eliminate the need to renew several expiring interstate pipeline contracts.