Challenge #28 ~ Power Management

Read the blog post on the September Theme – TECHNOLOGY

Photo by MaryBeth Stuenkel

Challenge #27 started our journey toward a greener use of technology through smarter purchasing. This challenge asks us to think about how to use that new tech responsibly. See the Technology blog for more background on the impact of our tech use on the environment.

Someone once told me that a kitchen microwave consumes more energy when it’s not in use than when it’s being used. That sounded pretty weird to me. After all, a microwave is supposed to be a pretty efficient way to heat food. So, how could that be? Well, let’s think about it and do a little math (just a little, promise).

A typical household microwave is rated for 1,000 watts, or 1 kilowatt (kW). Sara uses hers for one minute every day of the year (on average). That’s 365 minutes or about 6 hours. 1 kW * 6 hours = 6 kWh (kilowatt hours, the unit the power company uses to charge for electricity). Tom uses his a lot, for an average of 5 minutes per day, raising his power usage to 30 kWh.

However, the microwave is typically plugged in all day every day. It takes power to run that digital clock! An average microwave on standby is using around 5 watts (or .005 kW). Not much, right? But let’s do the math again. A year has 8760 hours. So .005 kW * 8760 hours = 43.8 kWh, even more than Tom uses to heat his food. That’s enough power to run an efficient laptop computer (see Challenge #27)  for 6 hours a day for a year.

Crazy, right? This provides just one glimpse into how you can save power, the fuel used to create it, and the money you pay Kahramaa to provide it for you. 

While much of the environmental impact of technology is in the manufacturing process, which is why purchasing decisions matter, how technology is used is also important. These power management techniques can help us use less power to save more on our power bills while benefiting the environment.

Get Started with these Tips

  • Use sleep or battery saving settings on devices to set them to automatically consume less power when not being actively used. These settings don’t shut the device off, but simply reduce unnecessary activity that consumes power, providing a good blend of convenience and power savings. While these settings are typically the default on new computers, it doesn’t hurt to check.
  • Turn airplane mode on at night to reduce the energy the phone uses during that time.
  • Use a power strip for monitors, printers, lighting, etc to allow us to easily turn everything off at once when we’re not working. 
  • When it’s not charging, turn off the outlet where a device is plugged in to eliminate vampire power (aka standby power). This applies to appliances such as microwaves and ovens, too! Unplugging or turning off outlets when we’re away from home for extended periods of time is an especially great time to do this.
  • Curious about how much power various electronic devices use? Measure power usage with a device like a Kill A Watt™ to find out where to get the most benefit from our efforts. 

Being smarter about how we use our devices can reduce the electricity they use, save power, and reduce greenhouse gas (GHG) emissions and additional heat load requiring more air conditioning. This challenge supports Sustainable Development Goals 12: Responsible Consumption and Production, and 13: Climate Action.

You, too, can help the environment, one kilowatt at a time.