At the world's largest trade show for consumer electronics, starting Monday in Las Vegas, manufacturers will be talking not just about megapixels, megahertz and megabytes, but about smart power adapters that don't waste as much electricity, batteries that are easier to recycle, and components made from plants.

Many of the products on display will be striking rather small blows for the environment, but the industry is realizing that even in electronics, going "green" can be a powerful marketing tool.

"Everything I've heard from folks out there is that there is going to be a lot of emphasis on green this year," said Scot Case, a vice president at consultancy TerraChoice Environmental Marketing.

One of the 2,700 exhibitors at the International Consumer Electronics Show will be Japan's Fujitsu Ltd., which will show off a laptop with a plastic case made from corn rather than petroleum products. The company has sold such a model in Japan since 2006, but is now considering taking it to the North American market.

Environmental awareness among consumers and corporations has now reached the point where manufacturers really are taking notice, said Richard McCormack, senior vice president of marketing at Fujitsu's U.S. arm.

"They're driving manufacturers like us with their pocketbook," McCormack said.

The catch with the corn-based laptop is that the material isn't biodegradable, meaning it doesn't decompose any faster than regular plastic. That's because it still contains some petroleum-based plastic for rigidity. The plastic still needs to be processed for recycling, after which the corn-based component can biodegrade.

Another company playing up recycling is Z-Power, which has developed a battery technology it hopes will replace the lithium-ion batteries that power today's laptops and cell phones. Its silver-zinc batteries will show up in laptops from a "major" manufacturer in the summer, the Camarillo, Calif., company's chief executive, Ross Dueber said.

Lithium-ion batteries are recyclable but contain little recoverable material. The metals in Z-Power's batteries will be recoverable, Dueber said, and with a precious metal like silver in them, there will be a strong incentive to do so. The capacity should be 20-30 percent higher than lithium-ion laptop batteries. The company is also in discussions with cell-phone manufacturers.

PC makers have already come a long way toward making their products recyclable, said Jeff Ziegler, chief executive of Austin-based TechTurn, which processes millions of used computers and other gadgets every year for recycling or reuse. Manufacturers have cut down on the number of different materials that go into their products, simplifying recycling. They've also cut back on lead solder and other poisonous components.

But as yet, only a few manufacturers, like Sony Corp., take responsibility for recycling their products. Just 12.5 percent of U.S. electronics waste is offered for recycling each year, the Environmental Protection Agency reports, and much of that is dumped rather than recycled.

At the show, the EPA will announce a campaign to give consumers more places to turn in cell phones for recycling, in partnership with manufacturers and retailers. The agency puts the number of unused cell phones lingering in drawers at 100 million.

Manufacturers are expected to use the show to trot out computers, especially laptops, that meet the EPA's new, tougher Energy Star 4.0 power consumption requirements, which took effect in July. The specification now sets maximum levels for power consumption when the computer is on but idle -- previously, Energy Star dealt only with the ability to enter "sleep" mode.

There won't be many desktop computers qualifying for the Energy Star rating -- their power consumption is growing, with many now hitting 400 watts. Marvell Technology Group Ltd. will be demonstrating chips for power adapters that it says can curb that trend, by convert alternating current into the direct current in a more efficient way, potentially power consumption by half.

The Consumer Electronics Association, the organization that stages CES, estimated last year that consumer electronics, including home computers, consume 11 percent of residential electricity in the U.S., more than doubling its share in 10 years.

Televisions are another big power draw, and will become more so as high-definition sets replace analog TVs. Though more energy efficient per inch of screen size, their larger size more than makes up for any gain in efficiency. Plasma sets in particular easily draw 400 watts, or as much as four older tube-type TVs.

A much more power-efficient screen technology will be on display at CES: Samsung Electronics Co. will be bringing a 31-inch TV made of organic light emitting diodes, or OLEDs. For now, the technology is too expensive for the mass market, and there's no word on when or if Samsung plans to sell the screen. Sony has announced an 11-inch OLED display for $1,700.

Cell phones, while hardly power-hungry, are wasteful: Nokia says two-thirds of the energy a charger uses is drawn when the connected phone is already fully charged. GreenPlug of San Ramon, Calif., will be previewing a solution to that problem, a universal power adapter that "talks" to gadgets to determine their energy need. Apart from cutting wasted electricity, GreenPlug aims to eliminate the need for a different adapter for every phone, MP3 player, and other portable gadget.