A new report by the National Resources Defense Council reveals that as much as $19 billion worth of electricity may be wasted in U.S. homes by devices when they’re not being actively being used. That is equal to the output of 50 large power plants – and could be costing costing every household between $165 at the average national rate up to $440 a year at some utilities’ top-tier rates.

The research in the report, Home Idle Load: Devices Wasting Huge Amounts of Electricity When Not in Active Use, shows idle load accounts for nearly 23 percent of all electricity consumed in California homes.

The good news as the report points out is that this is a problem that is easy to solve. “By making a few simple changes – to individual behavior, to manufacturer designs, to utility company efficiency programs, to energy standards (such as setting maximum levels of standby power across many devices) – we could minimize idle load and save a huge amount of energy.”