The debate about moving to a clean energy economy is over. The question is, how long will it take?

Some, like the recent Wall Street Journal article "The Long Road to an Alternative-Energy Future" by Michael Totty, posit "we shouldn't expect" clean technologies to significantly dent fossil fuel use anytime soon.

But while Rocky Mountain Institute agrees that new energy innovations in solar, wind and electric vehicles may take years to overtake existing products or technologies, there are several ways to make the road a bit shorter.

Efficiency: America's Greatest Untapped Opportunity

Totty noted that the sheer size of the energy market is a major reason for the clean energy delay. Yet efficiency measures greatly decrease the total size of the market and help ensure that the contribution of alternatives is more significant.

The challenge of supply cannot be tackled without considering demand-side solutions, and energy efficiency is the critical resource in the portfolio of energy solutions.

Researchers at RMI identified several near-term efficiency advantages in "Assessing the Electric Productivity Gap and U.S. Efficiency Opportunity."

According to the report, electric productivity (measured in dollars of gross domestic product divided by kilowatt-hours consumed) varies dramatically from state to state. If lower-performing states could achieve the electric productivity of top performers through energy efficiency, the U.S. has the potential to save 1.2 million gigawatt-hours -- equal to displacing over 60 percent of America's coal-fired generation.

Most importantly, this is possible through technologies available today. The efficiency gap can be closed using a broad range of strategies and solutions that are already being implemented -- just not to their full potential.