Nothing pleases a city leader like getting a high ranking on one of those "best of" lists that have become so common. There are hundreds of them, ranging from "best educated" and "most bike friendly" to "least expensive housing" and "lowest crime rates," and cities are quick to latch on to them to try to attract business, tourism, college students and even sporting events. One that I've never run across, however, is "best use of energy."

Such a list would be a true 21st-century creation, employing ever-improving technology to monitor and measure energy use--everything from electricity to natural gas to gasoline--for transportation, buildings, water and waste management. A fully integrated picture would consist of the energy flows in the entire city aggregated from data of its parts. Commercial buildings are starting to use these tools to track energy use, and it's already getting interesting.

Case in point: Charlotte, N.C., where a public-private collaboration, Envision Charlotte, aims to build awareness of personal energy consumption with the goal of achieving a 20 percent reduction in energy use across the community from a baseline level that takes into account fluctuations in the weather and building occupancy loads. Not only will data on individual building energy use be available, but public digital displays will show data on collective usage, and statistics now are online for the last 24 hours, seven days and 30 days.

Is there evidence that merely tracking energy use can result in less of it being used? Across the country, governments and utilities annually offer millions of dollars in incentives to decrease energy use. Government building codes enforce efficiency standards. But aside from incentives and regulations, will simply measuring and disclosing energy use increase efficiency?

A recent study by the U.S. Environmental Protection Agency suggests that it will. The three-year review of 35,000 buildings, using data from the EPA's interactive online Energy Star Portfolio Manager, showed annual savings of 2.4 percent.

Beyond voluntary initiatives such as Envision Charlotte, public policy has been an important driver in getting building owners to monitor and report their energy use. The Institute for Market Transformation (IMT), a Washington, D.C., based nonprofit, has been tracking state and local government adoption of energy benchmarking and disclosure regulations for several years and reports that these policies are having a real impact. "The improvements are typically operational changes, rather then physical ones, and more related to managing the building than upgrading equipment," says Andrew Burr, director of IMT's building energy performance policy. "This includes setting the HVAC schedule correctly, changing equipment start-up times, lighting levels, that type of thing."

Building owners and operators traditionally have given more emphasis to keeping their equipment running than to its efficiency, but that's changing with the availability of tools such as Energy Star Portfolio Manager that allow a building's energy performance to be rated on a scale of 1 to 100 relative to similar buildings nationwide.

There's more to this trend than environmental awareness. "A poor energy score is bad for marketing efforts," Burr notes. " The improvement we're seeing is driven by disclosure because both owners and prospective tenants can see a building's energy ranking."

That goes for cities' economic-development marketing efforts as well. Energy benchmarking not only gives public officials a new tool to foster energy efficiency, but, as Burr notes, is "also causing cities to look at scores from peer cities and gives markets better information about the city's commercial real estate."

Here's a thought. We're all familiar with the Energy Star appliance label. Now that we have energy labels for buildings, wouldn't it be fascinating to have a city Energy Star label? Benchmarking building energy use across a city is making that possible.

Who knows? I may see a mayor touting his city's top position on a "best use of energy" list sooner than I thought.