ASK THE EXPERTS: Home Electricity Monitoring


I’ve been a subscriber to this wonderful magazine longer than dirt. But, unless I missed it, you have never done an article, or a review, about different types of home electricity monitors.

I’ve done “everything” in the way of renewable energy over the last 35 years or so, but now I’m interested in reducing wasted energy by figuring out where all the electricity I use is going. I did a primitive monitoring of a fridge and freezer, by randomly noting when each was running and when they weren’t. From this, I determined the percent run time, multiplied this number by the rated power consumption in watts, and voilà—I determined how many kilowatt-hours per day were being used by each of these appliances.

It turned out that the old fridge was running about 25% of the time, and the older freezer was running about 75% of the time, so bye, bye, freezer. The new one not only draws less power, but it’s running only about 15% of the time.

But now I’d like to monitor everything. I’m told that a “smart meter” is capable of figuring this out, but I don’t want a smart meter, at least not one that can be hacked into, as that seems to be an open invitation to hackers/burglars so prevalent around here (well, not now, but maybe after we all get on smart meters).

I have perused what’s for sale, and have decided that Home Power folks are way better at figuring out stuff like this than I am, so how about an article or two? Besides, I am certain that there are others besides me who would find an article on this helpful. Thanks in advance, Home Power folk—you are rad!

Malcolm Drake • Grants Pass, Oregon

There’s a range of electric power monitoring tools, starting with the simple Kill A Watt and Watts Up? meters that simply plug into an outlet. These devices are ideal for evaluating the power draw and energy consumption of individual, 120 VAC appliances. Then there are whole-house systems and smart meters. “Beyond Your Utility Meter”  (HP138) reviews a variety of metering systems.

If your utility does not yet offer smart meters, whole-house energy monitoring systems, such as those made by The Energy Detective (, are available for $200 to $300. The much more complex and expensive systems, such as the eMonitor from Powerhouse Dynamics (, allow you to monitor every circuit in your home separately. Its price ranges from about $500 to $900, depending on the number of circuits you choose to monitor. Both systems have monitors that install in the main breaker panel to show detailed information on various devices from a small wireless display to your computer or your smartphone.

Smart meters provide you with detailed power draw and energy consumption information in near real-time via a Web portal, and save you the several hundred dollars that a whole-home monitoring system costs. While smart meters have been hacked, the only purpose for hacking one would be to cheat the utility company. Not all smart meters are hackable, however, and those that are require physical access to the meter. So far, there have been no known incidents of malicious hacking.

Power monitoring systems create a pathway for saving energy by increasing your consumption awareness. Many people have reported significant energy use reduction after installing energy monitors. There is an anecdotal story about a woman who installed an energy monitor that she could access from her smartphone. She looked at it on her way to work and noticed her energy consumption was 1,000 W higher than it should be, and returned home to check it out. She found that she had left the toaster oven on and that it was turning brown and beginning to melt. So you never know, maybe an energy monitor will also save you from burning down your house!

Guy Marsden, Energy Maven •

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