The PlayStation 4 and Xbox One consume much more energy than the previous generation of consoles, a new report from the Natural Resources Defense Council finds.

“We don’t have a problem with people playing games. But the problem is the amount of energy used when not playing a game,” NRDC’s director of high-tech energy efficiency and author of the report Pierre Delforge told USA Today.

The report explains that while all consoles have incorporated many energy efficiency features into their designs (like automatic power-down) since the last report in 2008, the increase in energy consumption comes from new features that rely on their standby or sleep modes. For example, the Xbox One uses 15 watts of continuous power in standby so you can turn it on with a voice command. A PC, by comparison, uses less than two watts when it’s in sleep mode.

The NRDC projects that if all the previous-generation consoles are replaced with the Xbox One, PS4, and Wii U, they will use roughly 10 billion kilowatt-hours of electricity a year, or the equivalent to the output of four large power plants.

Of the three, the Wii U is the only console to reduce its energy consumption from the last generation, down 8 percent despite offering more powerful hardware. It uses less than one watt in standby mode.

You can find the full report on NRDC’s website.