California, Massachusetts and Oregon have been named the top-rated states for energy efficiency, while New York, Vermont, Washington, Rhode Island, Connecticut, Minnesota, and Maine rounded out the top ten.

That's according to the annual State Energy Efficiency Scorecard report from the American Council for an Energy-Efficient Economy (ACEEE), a Washington, D.C. non-profit.

The group recognized that California, Massachusetts, and Washington have implemented their own transportation-related greenhouse-gas reduction targets. "California has retained its #1 ranking for the fourth year in a row, outpacing all other states in its level of investment in energy efficiency across all sectors of its economy," said the ACEEE.

According to the group, the transportation sector consumes about 28 percent of all end-use energy in the U.S.

Indeed, the Golden State has unveiled its own clean energy plan that goes above and beyond the federal plan—looking for one million EVs on the road by 2020.

The ACEEE, which rates each state on a scorecard basis, noted that Utah, Arizona, New Mexico, and Alaska are most-improved, mainly due to utility energy-saving programs and better building codes.

The scorecards include an evaluation of vehicle policies—like individual financial incentives or vouchers applied to hybrid or electric vehicles, or tailpipe emission standards—and of overall transportation system efficiency, looking at how regional plans cooperate and the way in which transportation and settlement plans are coordinated. In addition, the report looks at public programs, public utilities, building codes, total heat and power, and appliance efficiency standard.

North Dakota, Mississippi, and Alabama were the lowest-rated states for energy efficiency, while Texas and New Hampshire dropped the most in the annual rankings versus last year.

"Despite federal inaction on climate and energy policy, states are moving forward and advancing energy efficiency policies and programs in an effort to create jobs and stimulate their economies during a period of considerable economic uncertainty," said the organization.

[ACEEE]