The typical American home is full of vampires. Vampire electronics that is. Vampire electronics are devices that are always plugged in—basically, anything that has a light on, even when you’re not using it. While most devices have sleep or standby modes, they still continuously suck up electricity even when we’re not using them. And the more wired and connected we make our lives, the greater the number of vampires we end up with.

A report from the National Resource Defense Council states that Americans are spending $19 billion a year in electricity costs from vampire appliances and electronics. That comes down to $165 per household on average, but could cost as much as $440 per household under top-tier rates. The annual power usage is equal to the output of 50 large power plants and an equal amount of emissions.

“One reason for such high idle energy levels is that many previously purely mechanical devices have gone digital: Appliances like washers, dryers, and fridges now have displays, electronic controls, and increasingly even Internet connectivity, for example,” says Pierre Delforge, the report’s author and NRDC’s director of high-tech sector energy efficiency. “In many cases, they are using far more electricity than necessary.”

Two major offenders that we’ve discussed before are TV cable boxes and video game consoles. Cable boxes are the second largest energy user in many people’s homes because they are always running even when they are turned off thanks to spinning hard drives, program guide updates and software downloads. Video game consoles can be major power hogs and the systems’ stand-by modes leave much to be desired. Many users are reluctant to shut them off completely because restarting them can take such a long time when updates have to be installed.

While studies have focused on these individual electronics in the past, the NRDC study is the first to analyze the impact of all the idle electronics in our lives. The group looked at energy usage data from electric utility smart meters in 70,000 northern California homes as well as field measurements that concentrated on idle loads. They found an average of 65 vampire power loads in homes, including things like appliances, devices in standby mode (even things like garage door openers), electronics in sleep mode like game consoles and TVs, and devices like computers that are left fully on, but are not in use.

The always-on devices consumed an average of 164 watts per home, the same as brewing 234 cups of coffee every day for a year (more than 85,000).

The good news is that making improvements in your idle power load is easy.

“Consumers can take such steps to reduce their idle load as using timers, smart power strips, and changing settings on their devices, and manufacturers need to do their part by designing products to minimize energy waste, but ultimately policies like energy efficiency utility programs and standards are needed,” Delforge notes. “Reducing always-on consumption is a low-hanging fruit opportunity to cut climate-warming pollution.”

If you want some specific pointers, the NRDC did the hard work for us and put together this great list of actions for identifying and reducing your vampire power loads.