Replacing old office lights with more efficient fluorescent models, building consumer electronics and power strips that save energy, installing smart thermostats in homes: these are the kinds of energy efficiency programs that could help the United States shave its future power use by 22 percent by 2030. Moves such as these would save the country 236 billion kilowatt hours, or 14 times the energy consumed by New York City.

That's the conclusion of a report from the Electric Power Research Institute released Wednesday, which studied existing utility, government and industry collaborative energy efficiency programs to get a sense of how they would play out over the long haul.

The study looked at existing programs and technologies, and considered only those that could pay for their extra costs with energy savings, said Omar Siddiqui, EPRI's energy efficiency program manager. Also excluded were regulatory changes – only voluntary programs were included, he said.

And by far the biggest single point of savings – 22 percent of the total – could come from commercial lighting alone, he said.

"To some people, commercial lighting is an area where the low hanging fruit is seen to have been picked," he said. But according to the report, simple things like switching out old T12 linear fluorescent lights with more efficient T8 lamps  could provide savings of nearly 30 percent, with "a short economic payback period and a straightforward opportunity for utility rebate programs."

While the report said that new lighting technologies like light-emitting diodes (LEDs) could be valuable energy savers over the long run, most are still too expensive to make the report's economics cut (see Lighting the Way to Efficiency).

In the residential sector, the highest savings potential was in electronics, the report found, since "increasing numbers of devices with rising power demands create a large opportunity for efficiency gains." Building TVs, computers, video game consoles and other devices to use less power could lead to huge power savings over the long run (see CES Plugs Green Technology, Venture Power in Japan: Green Electronics and Dry Your Clothes With Half the Energy).

Improvements in home cooling, appliances and lighting also provided room for savings, with programmable thermostats providing the biggest savings in those categories, the report found.

Saving all that energy won't be cheap. EPRI estimated it would cost from $18.7 billion to $46.5 billion by 2030 to cut annual growth in power demand to 0.83 percent, down from the 1.07 percent predicted by the U.S. Energy Information Administration in its 2008 Annual Energy Outlook.

Still, the money saved by not needing to generate the power that could be saved would pay for those costs, Siddiqui said – and that's not counting "the societal benefits and resources conservation benefits associated with efficiency," he said.

Savings of 22 percent by 2030 aren't the limit, he added. If consumers were completely committed to the programs, the country could use 36 percent less power than EIA's 2030 prediction.

But given that no program is perfect in getting everyone on board, that might be a little much to hope for.

Efficiency programs aren't the only way to reduce power demand. An EPRI study released last month took on the energy savings that could come from various "smart grid" programs now in place could reduce the country's 2030 power needs by 4.3 percent (see EPRI Plugs Smart Grid for Energy Savings).