The NRDC report, Cutting Energy Costs to Connect to the Internet, estimates that it takes all of the electricity produced by three power plants to keep this small network equipment constantly running across the country.
"These energy vampires put greater pressure on the power grid which leads to more carbon emissions," said Suzanne Jones, vice president of marketing at the Association of Energy Services Professionals. "It's just waste; a waste of energy and money."
A few manufacturers already make energy-efficient modems and routers, but it's difficult to spot them because there is no Energy Star standard for this home equipment.
"The better mousetrap already exists," Horowitz told me. "It's time for that innovation to be a standard feature in the new modems and routers we buy at the store or receive from our Internet providers."
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The NRDC estimates that if all of this inefficient equipment were replaced with devices that used 25 percent less energy, it would cut the country's electric bills by $330 million a year.
Manufacturers respond: Let's not get overly excited
The companies that make home electronics insist they are concerned about energy efficiency and have been working on better home networking technology.
Doug Johnson, vice president of technology policy at the Consumer Electronics Association (CEA), believes the NRDC report needs to be put into perspective. The amount of electricity required to power modems and routers is a very small portion of your total home energy use, he told NBC News.
"Let's not make a mountain out of a molehill, if it's truly a molehill," Johnson said.
According to CEA's data, the typical home routing devices use about $5 to $6 worth of electricity a year which is about the same as a new 32-inch TV. By comparison, the average household spends about $15 a year to power the video game console, $75 to run the refrigerator and around $200 for lighting.
"And it's a tremendous value considering all the benefits we get as a result of networking and connection to the Internet – which include saving energy in various ways," he said.
Things are about to change
We should see significantly more energy-efficient modems and routers on the market in 2014.
The Environmental Protection Agency is developing a new Energy Star standard for modems, routers and other equipment used for network connectivity. The final draft of the specifications is expected this summer with an effective date of either late summer or early fall.
The electronics industry supports the idea of Energy Star certification for these devices.
So what can you do right now? You can turn your networking equipment off before you go to bed or leave the house for extended periods of time. Studies show some people do that. But, frankly, that can be a pain – and the system may need to reboot if you turn it off.