If the world’s video game aficionados made a few changes in computer settings and swapped some components for more energy-efficient models they could save $18 billion a year in energy costs by 2020, researchers at the Lawrence Berkeley National Laboratory say in a new report.

Video games currently use a surprising amount of electricity — 20% of all energy consumed by personal computers even though gaming computers represent only 2.5% of the personal computer base. Evan Mills, who co-authored the report, calculates that a typical gaming computer uses 1,400 kWh of electricity per year, six times as much as a typical PC and 10 times as much as a gaming console.

Potential savings by the year 2020 would be the equivalent output of 40 power plants rated at 500 megawatts each (a standard unit of electricity savings researchers call a “Rosenfeld”).

The report, “Taming the energy use of gaming computers”, was published in the journal Energy Efficiency.

“Your average gaming computer is like three refrigerators,” Mills says in a Berkeley Lab press release. “When we use a computer to look at our email or tend our Facebook pages, the processor isn’t working hard at all. But when you’re gaming, the processor is screaming. Plus, the power draw at that peak load is much higher and the amount of time spent in that mode is much greater than on a standard PC.”

Mills says he was surprised that such a huge source of energy use has so far been overlooked, and the report comes at a time when interest in video gaming is increasingly rapidly.

He estimates gaming computers used 75 terawatt hours of electricity (75 trillion watt hours) in 2012, which will double by 2020 given current sales rates — and assuming there are no efficiency improvements. Worldwide, some 1 billion people play video games on their computers.

“And,” he says, “the popularity of these giant desktop gaming computers is growing fast.”

New measures recommended

Mills dove into the topic after he helped his son Nathaniel (co-author of the report) build a custom gaming computer, a route chosen by one-third of all video gamers. They selected individual components — including the graphics card, motherboard, hard drive, and memory — to optimize gaming performance, and realized how much electricity the computer would consume as they checked power ratings on the parts.

“We’re building a power plant here,” Mills says.

Mills says gamers could save energy without sacrificing performance by choosing more efficient component configurations. By building five progressively more efficient gaming computers, researchers cut energy use by 50% while performance remained essentially unchanged. Additional savings were possible through settings on certain components.

The Mills found wide variation in the rated power consumption of different components. Power consumption for graphics processors, for example, ranged from 60 watts to 500 watts, with computing performance varying as well. But they found higher power consumption didn’t always mean faster processing. Some units with the highest performance used less power.

“The huge bottom line here is that gamers don’t have to sacrifice performance to save energy,” Mills says. “You can have your cake and eat it too. In fact, the efficient systems run cooler and quieter, both of which are desirable attributes among gamers.”

Nathaniel Mills later decided to drop gaming. He and his father developed a website called Greening the Beast, which is devoted to helping the gaming community “green up its act.”