The state's Energy Efficiency Advisory Council has renewed a three-year efficiency plan to be implemented by utility companies across Massachusetts. The three-year plan is based on a similar plan that expires at the end of this year, and aims to save residents and businesses nearly $9 billion.

NStar is just one of the utilities taking part, and spokesman Mike Durand tells WBSM News customers can save wherever energy is used.

Durand says an energy audit of your home or business is recommended before taking advantage of the many cost-saving programs.

Other utilities participating include National Grid, Western Massachusetts, Electric, Columbia Gas of Massachusetts, New England Gas, Unitil, Berkshire Gas, Blackstone Gas, and the municipal aggregator Cape Light Compact.

Massachusetts has been named the most energy efficient state in the country.