Allegheny County is entering into a 35 year deal to buy hydroelectric energy from the Emsworth Lock and Dam on the Ohio River.
County Executive Rich Fitzgerald says the power will go to the county courthouse, jail and other government buildings.
"Every single year, we will be producing as much energy that would power 3,400 homes," he said.
Over the life of the contract, the county will offset more than 1 million metric tons of carbon emissions.
The project is scheduled to start later this year and be operational in 2023.
