HAMPTON -- Public Service of New Hampshire completed an upgrade to its Timber Swamp substation in Hampton, concluding a two-year improvement effort of the Seacoast's power transmission system in time for summer's increased demand for electricity.

The $15 million project includes the addition of a new transformer and ancillary equipment, essentially doubling the substation's power capacity.

PSNH worked with the town of Hampton during permitting and construction of the project, resulting in an increase of conservation land in town. The substation is between two abutting conservation land properties. PSNH agreed to transfer to the town by deed 30 acres of Timber Swamp property, resulting in a contiguous strip of conservation land primarily traversed by wildlife.

The Timber Swamp upgrade was part of a larger project that enhances PSNH's distribution system to provide safe and reliable electricity to thousands of electricity customers on the Seacoast.

The Timber Swamp substation is noteworthy as pioneering technology in American electrical transmission. In 1982, it became the first substation in the nation to transform, or reduce, power from 345 kilovolts, which is used on the regional transmission system, to 34.5 kilovolts, for distribution to homes and businesses. Before this innovation, an intermediate reduction to 115 kilovolts was necessary. The innovation increased efficiency and was subsequently used at other substations.

PSNH is New Hampshire's largest electric utility, serving more than 490,000 homes and businesses.