In the US, Boston has won the title of most energy-efficient city for the second year running according to a scorecard compiled by the American Council for an Energy-Efficient Economy (ACEEE).
Boston, in the US state of Massachusetts, scored 82 points out of 100 based on the policy categories of utilities, local government, community, buildings and transportation.
Utility policies, which earned the city 17.5 points out of 18, include energy efficiency programs that offer high levels of savings.
Other cities that ranked well for energy utilities were San Francisco, Portland, Minneapolis, and Chicago.
ACEEE said these cities also have productive relationships with their utilities in program implementation and access to energy data.
In Boston, customers are connected to energy-saving services through Renew Boston, the city's partnership with local utilities.
And when it comes to improving efficiency in water systems, Boston, San Francisco, Seattle, New York City, Los Angeles, Austin, Atlanta, Fort Worth, and El Paso are leading the US, the association found.
At the bottom end of the scale, Oklahoma City was awarded just 12 points and ranked 51st.
ACEEE commented that the city needs to partner with utilities to increase investment in electric and natural gas efficiency programs and increase access to utility energy data.
Cities as drivers of energy efficiency
Commenting on the overall research, David Ribeiro, analyst and lead report author at ACEEE, said: "Our findings show that cities continue to be laboratories of innovation when it comes to energy efficiency, with many pushing the envelope for more energy savings in the last few years.
"Cities are also improving their approaches when it comes to tracking and communicating their efforts to save energy.
"By capturing these efforts in the Scorecard we hope local leaders from cities of all sizes can learn best practices from each other and deliver the benefits of energy efficiency to their communities, such as a stronger economy and a cleaner environment."
The report's metrics measure policies and programs that achieve one or more of the following - directly reduce end-use energy consumption; accelerate the adoption of the most energy-efficient technologies; provide funding for energy efficiency programs; set long-term commitments to energy efficiency; establish or enforce building performance codes or standards; reduce market, regulatory, and information barriers to energy efficiency.
ACEEE included 51 cities in this edition of the Scorecard, up 17 from the 2013 edition of the report.