Massachusetts is the most energy-efficient state for the second year in the row, while Mississippi is the state most in need of improvement, according to the American Council for an Energy-Efficient Economy’s (ACEEE) 2012 State Energy Efficiency Scorecard. Oklahoma, Montana, and South Carolina are the most improved states since 2011, according to the scorecard.

The scorecard benchmarks all 50 states and the District of Columbia based on policies and programs that encourage energy efficiency in a number of economic sectors. In addition to examining building energy codes, the scorecard looks at five other primary policy areas: utility and public benefits programs and policies; transportation policies; combined heat and power policies; state government-led initiatives; and appliance and equipment standards.

Nearly half of the states have adopted and adequately funded an energy-efficiency resource standard that sets long-term energy savings targets and drives investment in utility-sector energy-efficiency programs was one notable development highlighted in this year's scorecard. The most aggressive targets, according to ACEEE, are in Arizona, Hawaii, Maryland, Massachusetts, Minnesota, New York, Rhode Island, and Vermont. Also of note is that 10 states have adopted new building codes that exceed the international Energy Conservation Code (IECC) of 2009 or ASHRAE 90.1-2007 for residential and commercial building construction. Two states—Maryland and Illinois—have adopted IECC 2012.

The most energy-efficient states are:
1. Massachusetts
2. California
3. New York
4. Oregon
5. Vermont
6. Connecticut
7. Rhode Island
8. Washington
9. Maryland
10. Minnesota

The most in need of improvement, from last place, are:
50. Mississippi
49. North Dakota
48. West Virginia
47. Wyoming
46. South Dakota
45. Alaska
44. Kansas
43. Missouri
42. Louisiana
41. Nebraska

A full map of the scorecard, with links to details on each state is online at aceee.org/sector/state-policy/scorecard.