CHARLOTTE, N.C. - Duke Energy Corp. is taking a second step into pig poop.

The country's largest electric company is announcing a deal Tuesday to collect methane gas from animal waste and convert it into fuel for two of its existing electricity plants.

The Charlotte-based utility said its 15-year deal with Wilmington-based Optima KV should capture enough methane to power about 880 homes a year. Duke Energy announced a similar, larger deal in March.

The project involves building a unit at participating farms in Duplin County that will free the methane gas, which is then cleaned to required standards and injected into the underground natural gas pipeline network.

A North Carolina law requires electric utilities in the country's second-largest pork producing state to begin generating some of their power from swine and poultry waste.

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