Earlier this month, the utility asked the state Public Utilities Commission to consider a conservation project built around partnerships with many large residential builders. The goal is to encourage the use of high-efficiency air-conditioning units.

If approved by state regulators, Nevada Power would pay 50 percent of the cost of installing units with a 13 SEER rating on homes, up from the standard 10 SEER. The bigger units are 30 percent more efficient and could save consumers as much as $200 a year in utility bills.

Among the builders involved are Pulte/Del Webb, KB Home, American West, William Lyon Homes, Toll Brothers Inc. and 20 other major builders.

The new air-conditioner project is one of several efforts included in the PUC filing. The utility also is seeking to expand its promotion of Energy Star appliances, its refrigerator recycling program and its Sure Bet incentives for conservation among commercial customers.

The PUC will not decide on a series of added expenses for the utility in order to finance the measures. In its regulatory filing, Nevada Power said the moves would require an overall increase in the 2005 Demand Side Program from $10.8 million to $12.9 million. The 2006 program budget would jump from $10.7 million to $25.6 million.

As part of those increases, the air-conditioning program will jump from $2.6 million in 2005 to $4.7 million, increasing the number of rebates from 4,600 to 10,488 by the end of the year. For 2006, the budget would spike from $2.6 million for 4,600 rebates to $15 million for 31,856 rebates.

The proposal also would extend the refrigerator recycling program, scheduled to expire this year, into 2006, allotting $1.2 million for 6,500 recycled units.

The Energy Star appliance rebate program would be boosted from $700,000 to $1.2 million and the Sure Bet program would be increased from $1.6 million to $2.1 million.

In the PUC filing, Lawrence Holmes, manager of customer programs and strategy for Nevada Power, said the effort to upgrade air conditioners being installed by homebuilders could reduce consumption by 80 million kilowatt hours a year. That would translate into a savings on fuel and purchased power for the company of at least $3.6 million annually.

The measures also will help the utility keep up with Assembly Bill 3, a law approved this year. It allows the utilities to use conservation credits as part of the equation in determining compliance with Nevada's renewable energy usage mandate. The measure, however, requires that 50 percent of any energy savings come from residential sources.

There is, however, a problem with that mandate, the utility points out.

"In future years it will not be possible for Nevada Power to achieve 50 percent of the energy savings from residential programs using existing programs," Holmes said in his testimony.

To develop new programs, the company also is seeking to produce new plans with the assistance of a boost in its Technology and Market Trials Program from $125,000 to $625,000.

Kevin Rademacher covers utilities and finance for In Business Las Vegas and its sister publication, the Las Vegas Sun. He can be reached at (702) 259-4069 or by e-mail at kevinr@lasvegassun.com.