Energy efficiency advocates are working to enlist broader support and leverage existing influential backers at a time when government commitment is becoming more uneven across North American jurisdictions.

Analysis of nearly 133,000 households across the United States reinforces intuitive assumptions about who is most likely to invest in energy-efficient appliances.

Halogen and incandescent bulbs still garner strong sales for residential purposes, while LEDs are gaining market share through displacement of compact fluorescent lamps.

No country is a candidate for the Dean's list, but Germany tops the rankings of 23 countries that account for three quarters of world energy consumption with a score of 73.5 out of 100. The average score is 51, although eliminating Saudi Arabia's exceptionally low performance would push it up to 53.