The US state of Pennsylvania is investing $5m in eight projects that use biological waste such as sewage, animal and food processing waste to generate energy.

The projects include the installation of a 1.1MW biogas-powered energy recovery system at a dairy plant in Cumberland, and construction of anaerobic digesters and improvement for manure management at small dairy farms in Lebanon.

The projects are expected to generate more than 470,000MW hours of electricity over their lifetimes.

The projects will also generate the equivalent of 3,183 million cubic feet of natural gas and reduce the CO2 emissions by 237,000t.

Pennsylvania governor Rendell said the projects will also develop methods for handling various waste streams in a more efficient and environmentally friendly way.

The projects will also leverage an additional $22m in private investments, according to the State.