Massachusetts was ranked the most energy efficient state for the third consecutive year, followed by California, in the seventh annual edition of the State Energy Efficiency Scorecard, released by the American Council for an Energy-Efficient Economy.

Massachusetts' ranking is largely due to the state's Green Communities Act, signed into law in 2008, which requires utilities to invest in energy-saving techniques. And California's stringent requirements for reductions in greenhouse gas emission reduction requirements kept the state toward the top of the list.

Although Mississippi ranked among the top five most improved states this year, the council found that it still had a ways to go, landing it on the top five list for states in need of the most improvement, behind North Dakota, Wyoming, South Dakota, and Arkansas.

About 20 states fell in rank this year on the report:. Idaho in particular fell the furthest by nine spots since it failed to keep up with other states in utility efficiency spending and savings.

Check out the energy efficiency scorecard here.

The Top 10 Most Energy-Efficient States

  1. Massachusetts
  2. California
  3. New York
  4. Oregon
  5. Connecticut
  6. Rhode Island
  7. Vermont
  8. Washington
  9. Maryland
  10. Illinois

-Linsey Isaacs is an assistant editor with Multifamily Executive magazine. Follow her on twitter @LinseyI  to continue this conversation.