Television sets may not seem like energy guzzlers. But with screens that rival the size of small billboards, some use as much power each year as a new refrigerator.

"The great news on TVs is, energy efficiency is clearly on the map for TV makers," says Noah Horowitz, a senior scientist with the Natural Resources Defense Council. "They are talking loudly about how good their TVs are, and it's real."

At the recent Consumer Electronics Show in Las Vegas, Horowitz says many manufacturers were showing off televisions that use 50 percent less power than previous models, with all the same features.

For more than a year now anyone with a TV has been bombarded with public-service announcements about the transition to "digital only" broadcasts beginning Feb. 17. Congress recently voted to delay the switch till June 12, although some broadcasters plan to stick to the original date.

Eight out of 10 homes in the United States already have digital capability through their cable, satellite or phone company. The June transition won't impact them at all.

The other 20 percent have choices: Subscribe to cable or satellite TV, buy a new digital TV, or purchase a converter box to keep an older, analog TV working. The choices people make could have a big impact on their electric bills.

The federal government sent out a billion dollars worth of coupons to help analog viewers purchase those converter boxes if they just want to keep their old sets. Most cost about $30 with the $40 government coupon.

The NRDC has some other tips for making a green TV choice. Look for the "Energy Star 3.0" label. Energy Star is a voluntary program run by the Department of Energy (DOE) and the Environmental Protection Agency. The top 25 percent of models that use the least power qualify for the label. The EPA calculates that if all U.S. sets met that requirement, energy savings would be about $1 billion and greenhouse gases would be reduced, equivalent to taking a million cars off the roads.

It is easy for consumers to get lost in the jargon of today's TVs, which are often the most used home appliance. Not only do they provide hundreds of channels (how could we live without a dozen poker channels?), but for millions of families they're also "video game central" and the place to watch DVDs. While a salesperson may want to wow you with geek-speak, and sell you the most expensive set, be armed with some solid energy information before you buy.

Given a choice between a plasma screen and an LCD (liquid crystal display), the LCD is definitely the greener choice. Some plasma screens use two or three times the power of the same-sized LCD.

Be alert when doing the initial setup of a new TV. Even though many confident buyers believe reading the owner's manual is for wusses, one wrong click on the menu could mean a spike in your electric bill. NRDC suggests selecting the "home" mode, plenty crisp and bright for just about any room. The other choices, "retail" and "vivid" modes, can suck up 10 to 30 percent more energy.

Invest a couple of bucks in a power strip. Use it for your TV and all its peripherals: DVD player, converter box, sound system. When you switch the strip off, you aren't consuming that phantom electricity that keeps these appliances in standby mode.

And if you're replacing any of your family's TV sets, don't just put it on the curb to add lead and other toxic metals to a landfill. Give it to a neighbor or a charity. Or find a way to recycle it. Major electronics companies and universities periodically hold electronics recycling drives.

Both environmental groups and industry will be looking to the Obama administration to do even more to update government standards for TV efficiency.

Thirteen major players, from Walmart to Pacific Gas & Electric to NRDC have petitioned the DOE to scrap the current test methods, which are more than 30 years old, and designed for analog, cathode-ray-tube TV sets. Those standards are almost useless for modern digital televisions. The Bush administration didn't respond to the request. Horowitz says it would be an easy fix for the DOE to create meaningful energy performance testing and labeling, and save a lot of energy.