We are cool. We are slick.

We are downloading apps on our iPhones. We are engrossed in our e-readers. We are tapping away on our ever-more-slender laptops. With every easy stroke, we show ourselves to frolic happily through our modern, electronic habitat.

The efficiency with which we send a message around the world or receive one from a distant land makes letter-carrying, airmail and driving across town to hang out with a friend seem to be such dirty, carbon-intensive exercises. So twentieth century.

It’s empowering to flash the passport of a virtual citizen. And, to a greater extent than one might think, it’s also power gobbling.

Even as personal electronic equipment becomes more energy efficient, the complex of servers, routers, big computers and back-end machinery that it takes to run the virtual world is sucking up more and more of the planet's -- and certainly our nation’s -- electricity. The U.S. Energy Information Administration projects in its “Annual Energy Outlook 2010” that the large devices populating the back-end of that electronic habitat will be one of the fastest growing energy-demand segments during the next 25 years.

“As reliance on the Internet for information and data transfer increases, electricity use for ‘other’ office equipment -- including servers and mainframe computers -- surpasses that for commercial refrigeration in 2018,” the report says.

For a variety of very natural reasons, we tend not to notice the energy consumption inherent in the information economy.

One of those reasons is design. I’m an Apple fan boy. And each time I get a new gadget, it’s thinner and crisper than the last, and the battery can run the product for longer. The MacBook Pro simply looks more efficient than the MacBook. The iPhone 4 is lighter and thinner than the iPhone 3.

That image of efficiency is based on the modernist appeal that form must follow function. Waste is ugly, and the computers that sell well are pretty.

At the same time, that image isn’t lying. Personal electronic equipment is getting more efficient. Even though we’re spending more time on our various devices, they’ll gobble up a far smaller percentage of our energy by 2035, according to that same EIA study. Other than lighting, which is projected to show a net reduction in home electricity use over the next quarter century, PCs and related equipment show the slowest growth. The story is similar in the commercial sector.

Part of the reason for the increasing efficiency of personal devices is consumer pressure. Marketing one’s device under the Energy Star label has become a good business practice -- particularly to the young, environmentally conscious part of the population that (I’m guessing) spends a disproportionate amount of time on computers and smart-phones. So Apple, Dell, IBM and Motorola make an extra special effort to show off their Energy Star ratings and to promote their latest green-novations.

That feel-good marketing message doesn’t carry the same weight in the engineering departments of major corporations. Energy efficiency is important, to be sure, but only to the extent that it saves companies money. And electricity goes so cheaply in the United States that it plays a far more marginal role in buying decisions than, say, capital cost or performance standards.

Add in the trend toward cloud computing. Personal devices are expected to slim down even further as more functions and data move off those devices and onto the worldwide complex of servers. So the buying decisions that effect energy use will move further out-of-range of consumer demands for more efficiency.

Which brings us back to the hard reality we always seem to run up against when musing over our current energy predicament: Of course, we want to believe the good news, that the values of consumers and the resourcefulness of entrepreneurs will lead to innovations that reduce our collective carbon footprint. But the hard truth is that change will boil down to a business decision: Only putting a price on carbon emissions will reduce carbon emissions. And until we find a way to include that price in our energy bills, true efficiency will escape us.

Journalist Ken Edelstein writes the Planet Pundit column for the Mother Nature Network. From various coffee shops in Atlanta, he publishes an environmental news site at MyGreenATL.com.