Whirlpool has announced its plan to incorporate a new liquid blowing agent for the insulation used in its U.S.-made refrigerators that it claims will deliver better performance and higher energy savings. Manufactured by Honeywell, the Solstice Liquid Blowing Agent is being hailed as a superior alternative to commonly used hydrocarbons. In addition to Whirlpool refrigerators, the insulator will be used in refrigerators from Maytag, KitchenAid, Amana and Jenn-Air.

"Whirlpool Corporation is an environmental leader, developing high-quality products that offer both efficiency and low environmental impact," said Ludovic Beaufils, general manager refrigeration and sustainability lead for Whirlpool North America, in the news release. He predicts efficiency improvements ranging from two to 10 percent.

Energy efficiency has become big business in the appliance industry. Back in 1975, a typical refrigerator consumed about 1,750 kilowatt-hours (kWh) per year. Today that figure is down around 500 kWh, thanks in large part to efficiency standards that have become progressively tougher over the last three decades. Short of a solar-powered refrigerator that produces more energy than it uses, the efficiency gains will eventually run out. But we're not there yet. In fact, a target of approximately 400 kWh has already been set for 2015.

Efficiency standards are not without their detractors. A report published last month by the Mercatus Center entitled Overriding Consumer Preferences with Energy Regulations argued that efficiency standards restrict consumer choice without saving them money. The American Council for an Energy-Efficient Economy offered a rebuttal to the report, contending that it contains false claims and inaccurate assumptions.

Whichever side of the regulatory debate you're on, there's no doubt that refrigerators have gotten a lot more innovative since efficiency standard were first adopted. Whirlpool won't begin production with the new blowing agent until next year. But in the Consumer Reports refrigerator labs, we see several innovations that are available today. That includes linear compressors, dual-capillary energy valves, and vacuum-insulated panels.

If you're shopping for a new refrigerator, and energy efficiency is a priority, you can look for models with these innovations. Though you might find it easier to simply compare the energy efficiency score in our refrigerator Ratings, along with the annual energy costs of models on your short list. Our Ratings of more than 250 models include many refrigerators that do extremely well on both counts, while also delivering excellent temperature performance, a competitive price, and a host of convenient features, such as ice and water dispensers and temperature-controlled drawers.