Measuring our electricity consumption

In 2016, the year we moved to The Hague, I wanted to know the power consumption of specific devices in our new house. With that knowledge I could devise a plan to lower my electricity bill. Not that it was high, but saving money is always a good thing.

At that moment it was hard to investigate. I only possessed a cheap power consumption meter with a plug, which can be placed between the device to be measured and the wall socket. It didn’t work optimally because it would still report wattage when no device was connected, which made measurements inaccurate. Also, I couldn’t use it for devices where I had difficult or no access to the plug, like my built-in refrigerator.

Wat I also did was note the number on the electricity meter at the first day of the month and collect the data in a LibreOffice Calc file to compare total consumption per month throughout the year. This didn’t go well because I forgot to do it once in a while and because we weren’t home at the first of the month during the summer holiday.

However, this year the smart electricity meter was installed in our home, as part of the national project to do so in every home. Because it automatically sends the daily data on total power consumption to the power company it was no longer necessary to this myself. Now I can easily see the data in the smartphone app of my power company Qurrent.

This way I could see that July, August and September had electricity consumption figures which were quite normal for our situation, until our daughter Rosalinde was born in October. Because Stephanie was at home much more often due to her leave from work, electricity consumption shot up to one and a half times the usual level. Now that her leave is over, she still works four instead of five days a week and her mother takes care of our daughter for two days at our home. So the electricity consumption will remain structurally higher.

Fortunately the smart electricity meter also has a setting which shows the total consumption right now. What I would do then is the following: note current consumption on the meter, switch off refrigerator and note consumption again. Of course you have to turn off as much other devices as possible to prevent interference with the measurement.

The problem is of course that a refrigator has different consumption when it is on standby and when it has to cool actively. There is a specification of the producer for the yearly consumption conforming to the EU standards, but you will have variation because your refrigerator can have less or more ice in it. This means measuring is always difficult. And some of our devices were purchased before the EU made energy labels compulsory.

To conclude I used a combination of measurements with the power consumption meter, the smart electricity meter and the official specifications to get consumption figures for all my devices. I then noted these in this LibreOffice Calc document. In the baseline measurement (tab “Before”) I had several electricity guzzling halogen lamps; since then I have replaced them all with LED lamps. Those and other measures I had taken where then noted in the second measurement (tab “After”). All of this was measured before our daughter was born and electricity consumption increased sharply.

What caught the eye was the high consumption of my ventilation system, which is integrated in my air heating unit. At some distance come the refrigerator and the dishwasher. I don’t think the 280 washing cycles of the official consumption figures are accurate for us, so true consumption will probably be lower. The clothes dryer doesn’t have an energy label, but does have consumption figures for specific settings. We dry laundry as much as possible without the clothes dryer, outside in the summer and inside on clothing racks in the attic during the winter. Only if the racks are full or if there are towels (Stephanie likes to have them softer from the dryer) the dryer is turned on. Finally the aquarium and the router are relatively demanding users.

To be honest I haven’t asked for quotes yet, but I suspect the replacement of my ventilation system and air heating unit will be very expensive. Especially if I want to do it completely right and want to stop using natural gas. I think I’d prefer to wait for the plans of the municipality of The Hague. In 2021 municipalities have to make a plan for the heating of the built environment. It would be a pity if the municipality would be able to connect my whole neighborhood to geothermal heating while I would have already invested money in an air-source heat pump.

Other options to replace electricity guzzling devices by more economical ones aren’t profitable either. If I take a look at my calculations (tab “Alternatives”) I see the break-even point, where the savings on electricity compensate the purchase price of the device, is reached far too late. So replacement only makes sense when the current device breaks down. And Stephanie wants to keep her aquarium. Measures such as replacing the powerline adapters with WiFi and turning off the router at night seem more attainable. To reduce my natural gas consumption I put a kitchen timer in my bathroom, so I don’t take showers for more than five minutes.

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