Hawai'i's homes are the most energy efficient in the nation on average, according to a ranking by Microsoft Corp.

The software giant compiled a list of average energy efficency scores for homes in each state and found Hawai'i homes came at 81. That compared to the national average of 61.

Called Hohm Scores, the analysis compares a home's actual and potential energy efficiency. Microsoft said its www.microsoft-hohm.com makes available scores by ZIP code, city and state.

"The Hohm Score provides an easy way for anyone to measure their home energy efficiency, and compare it with others," said Troy Batterberry, Microsoft Hohm product unit manager.

"If each of the 60 million households improved their Hohm Score by five points, collectively that would equal an estimated $8 billion in savings a year."