California and its utilities have achieved remarkably consistent energy efficiency gains for three decades. How did they do it?

In part, a smart California Energy Commission has promoted strong building standards and the aggressive deployment of energy-efficient technologies and strategies — and has done so with support of both Democratic and Republican leadership over three decades. I talked to California energy commissioner Art Rosenfeld — a former DOE colleague and the godfather of energy efficiency — about what the state does, and here are some interesting details he offered, as discussed in “Why we never need to build another polluting power plant”:

Many of the strategies are obvious: better insulation, energy-efficient lighting, heating and cooling. But some of the strategies were unexpected. The state found that the average residential air duct leaked 20 to 30 percent of the heated and cooled air it carried. It then required leakage rates below 6 percent, and every seventh new house is inspected. The state found that in outdoor lighting for parking lots and streets, about 15 percent of the light was directed up, illuminating nothing but the sky. The state required new outdoor lighting to cut that to below 6 percent. Flat roofs on commercial buildings must be white, which reflects the sunlight and keeps the buildings cooler, reducing air-conditioning energy demands. The state subsidized high-efficiency LED traffic lights for cities that lacked the money, ultimately converting the entire state.

California adopted regulations so that utility company profits are not tied to how much electricity they sell. This is called “decoupling.” It also allowed utilities to take a share of any energy savings they help consumers and businesses achieve. The bottom line is that California utilities can make money when their customers save money. That puts energy-efficiency investments on the same competitive playing field as generation from new power plants.

If you really want the specific strategies that California utilites use to save energy, here are the “approved program implementation plans” for 2006-2008 from one of the state’s largest utilities, Southern California Edison.

The cost of efficiency programs has averaged 2 to 3 cents per avoided kilowatt hour, which is about one-fifth the cost of electricity generated from new nuclear, coal, and natural gas-fired plants. And, of course, energy efficiency does not require new power lines and does not generate greenhouse-gas emissions or long-lived radioactive waste. While California is far more efficient than the rest of the country, the state still thinks that with an even more aggressive effort, it can achieve as much additional electricity savings by 2020 as it has in the past three decades.

The energy-efficiency resource is enormous, and it is as limitless.

It is time to stop building polluting power plants.

This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.