The US can reduce energy use by 30% through efficiency alone.

"Rocky Mountain Institute's Energy and Resources Team has just published a report that shows the opportunity for 30 percent energy savings in the United States. Assessing the Electric Productivity Gap and the U.S. Efficiency Opportunity analyzed electric productivity state by state, and found a significant gap between the highest and lowest performing states.

productivity measures how much gross domestic product is generated for
each kilowatt-hour consumed ($GDP/kWh). This finding is significant
because if laggard states achieved the electric productivity of the top
ten performing states through energy efficiency, we would achieve
electric savings equivalent to more than 60 percent of U.S. coal-fired
generation. According to Natalie Mims, Consultant on RMI's Energy & Resources Team
(ERT), "closing the electric productivity gap through energy efficiency
is the largest near-term opportunity to immediately reduce electricity
use and greenhouse gases, and move the United States forward as a
leader in the new clean energy economy."

electric productivity of top performing states, like New York,
Connecticut, and California, serves as an example of what's achievable.
Those states show the nation how barriers to efficiency practices can
be overcome, how state utilities can be regulated, and how new and
effective technologies can be implemented. Conversely, lower performing
states have a huge opportunity to learn from the successes of higher
performing states by closing their electric productivity gap using
known and tested technology and policy. This will be the focus of
RMI's next step, as ERT concentrates on the efficiency measures that can cost-effectively have the largest impact." - - RMI e alert Newsletter 05/02/09

has been on the forefront of research and policy recommendations
regarding efficiency for as long as I can remember. Their latest report
is startling. Check out the interactive map to see how your state is doing.