plug load occupancy

Can power strips be smart?

In offices all over the country, employees are charging their cell phones, powering their personal fans, space heaters, desk lamps, and computer monitors. It doesn’t seem like a lot, especially when you think of all the other big energy-consuming things at work, but in California, office equipment equates to 7% of all commercial energy consumption! That’s a lot! And in the majority of Central Valley small offices, that amount jumps up to almost 20%! It’s almost as much as your air conditioner or your overhead lights!

So when we have our cubicle devices on, we employees sometimes forget to turn them off when we leave for lunch, or even before leaving to go home for the day. You do it, I do it, we all do it. It’s inevitable, but it’s fixable. So naturally, there’s a lot of savings left on the table when this behavior happens. Plug Load Occupancy Sensors--what is essentially a power strip with an occupancy sensor attached to it--exist to help you get that back. They replace a workstation’s regular power strip and serves to turn off power to ancillary devices (monitors, desk lamps, heaters, phone chargers, etc.) when occupancy is not detected, by using an occupancy sensor that you would normally see on the ceiling or in the corner of a room. They come with special outlets that keep your computer tower on, and a special outlet that switches the auxiliary outlet. It checks the power draw going to the device, and if you were to drop the power draw, say by turning off the monitor, the power strip recognizes this, and turns off all the auxiliary devices. Neato! These set-it-and-forget-it devices are great, because they do what I sometimes (okay, often) forget to do.

These devices are very cost-effective and are pretty inexpensive to begin with. Both PG&E and SCE provide a rebate of $15 per sensor, and most sensors cost around $55, after rebate. While that might seem like a lot for what’s essentially a smart power strip, each one saves on average $37 per year, making this product’s payback around 1.4 years! These last a long time too, around 8 years, meaning each one can net you $240 over the course of its expected lifespan.

Here’s a list of devices commonly found in cubicles, and their respective energy consumption in various states of use: