Monitoring and Reducing ElectricIty Consumption to Signficantly Lower Electric Bill

Monitoring and Reducing Electricity Consumption to Significantly Lower Electric Bill

Reducing Electricity Consumption to Lower Electric Bill

Yesterday night, I texted a question to my friend Jason of UltimateAir concerning his typical electric consumption with his passive house, especially now that both he and I haven't been operating any heating or cooling for nearly a month.

I got his response this morning.  His most recent electric bill was merely $28 or just 159kwh for the entire month!  Simply incredible for a 3200sf duplex passive house.  And here I am pleased that we are averaging merely 22kwh per day or 660kwh per month or about $98 a month for 6600sf.  I actually believe his meter reading was unrealistically too low from his electric company (relative to his other months).  We'll get a better handle on that come his next actual meter reading.

In any event, it got me motivated to seek out additional sources of our unnecessary or wasteful electrical consumption in our own passive house.  So, once again I set out with my amp clamp to look for those sneaky consumers of electrical energy. 
If you recall in a previous article I had located two sources--the phantom loads of our two ductless mini-splits--that were using a combined total of 4kwh per day or 120kwh per month of electricity. By shutting the minis off completely at the electrical panel we eliminated this waste.

I am pleased to report that we have disconnected our LED TV and have not watched any television for more than a month.  Not only do we feel better about ourselves and have more free quality time together we've eliminated our "entertainment" system from our energy profile.

We have a PC-based server and network system running 24/7 which consumes several kilowatt hours per day, but that is an essential component.  I am looking to virtualize our server and run multiple instances of operating systems on it and possibly replace the entire server with a low-power laptop, but this may be too extreme of a step.  Additionally, I use laptop.  We also have had a color laser printer online continuously as well as a fax machine and we are going to turn them off and then our Grundfos hot water recirculation system to also examine their impact on our electric bill.

I started looking at our whole house consumption at the main 200amp panel by clamping each 120v leg.  I then started clamping each circuit.  After about five minutes of clamping I found yet another high consumer of electricity.  It was our dual-zone wine cooler!  This little wine chiller has been consuming in excess of 5kwh/day or 20% of our current total electric consumption.  This amounts to another 180kwh month , nearly $30 month, or $360 year!

Being an oenophile certainly is coming at a price.  But even my vintage Dom doesn't justify this high operating expense. $360 year is nearly the operating cost of a conventional electric hot water heater and more than four times the operating cost of our 30cf refrigerator/freezer!  By eliminating this energy hog, we have managed to reduce our daily consumption rate of electricity to merely 15.6kwh or about 468kwh per month during this time of year.  This amounts to an electric bill of $60-$70 at prevailing electricity rates, taxes, and tariffs.

It also suggests that if we ever were to incorporate an active PV system, we may only require a small 5kw system.  As we collect more data over the coming seasons, we'll have a better handle on what would be the appropriate size of such a system.  I would recommend using this approach--determining your actual electrical footprint--before purchasing a photo-voltaic system of a given size.

By eliminating both the phantom loads of the mini splits and the excessive consumption of the wine cooler we've knocked off nearly 11kwh per day or 330kwh month--representing or whopping 40% reduction of our electric bill!  That's huge, any way you slice it.

I have begun looking for a more energy efficient wine cooler.  So far it appears that I have found one that consumes 1.5kwh per day--about $7 of electricity per month or $84 a year.  At a savings of nearly $280 a year, it would pay for itself in short order.  By the way, any one want a wine cooler?

It most certainly pays to do your research before making a purchase of an appliance.  Living in a passive house and being energy aware has given us a great appreciation of the value of actively monitoring, managing, and reducing our energy (carbon) footprint.

While I don't personally care for the "hype" sometimes found in articles suggesting a generalized 90% reduction in electric bills--because of appliances, lights, and other electronics not related to heating or cooling--one can certainly have significantly less expensive electric bills with a passive house, energy efficient appliances and electronics coupled with prudent behavior.

Even if one doesn't live in a passive house, it still pays to examine closely your energy consumption, manage it, and seek ways to eliminate or, at least, reduce wasteful electricity use.


  1. Hi Bob

    Wanted to give you an update on my retrofit.

    Do you have an email address you can send me.



  2. I have a Fujitsu 12RLS2, and was wondering about phantom loads as well, but have never measured it directly. How much load did you measure? If it's 4kWh/day for 2 units that must be 83W standby for each unit - is it really that bad? I wonder, if you used an amp clamp, maybe you saw a reactive load, and got apparent power not true power.

    My whole house idles around 130W; if my minisplit is draining 83W that's huge.

  3. I would say, yes in your instance the contribution to your load as a percentage is even more significant than our own! We figure about 75 watts each. To me that's a lot for sitting in a standby mode waiting to be turned on by a remote.


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