How to look after the watts

The bill payer running around the house screaming at teenagers to ‘turn that light out’ was a sit com staple in the 1980’s, but with electricity bills going through the roof it is no longer a subject for cheap jokes. Before you start looking at turning off everything in your house, though, it might be worth taking a closer look at where your electricity is going. x

It helps to understand how electricity usage is measured and priced. You pay for each kilowatt hour (kWh) you use, currently at a rate of around 34p if you pay by direct debit. A kWh is the power, or number of watts, a device uses multiplied by the time for which it is using power. So a washing machine, say, that uses 500 watts for two hours will use 1kWh (a kilowatt is 1,000 watts). 

If you have a smart meter and a device that shows how much energy you are using it is easy to see the difference turning on a kettle or hairdryer makes. But there is another important element to your consumption that is harder to see, which is the base load. This is the power your house uses even when you are asleep or on holiday. 

When we first got a smart meter, we found that even when we thought nothing was going on, the house was drawing a not inconsiderable 541 watts all the time. So, every day our base load was 541 x 24 or nearly 13kWh, costing £4.42 a day at the current capped unit price.

We decided to find out what was drawing all this power. We happened to have a remote-controlled plug we use to switch our Christmas lights on and off which measures the power used by the device connected to it. You can buy similar plugs quite cheaply. 

Moving this plug around the various sockets in the house enabled us to figure out where we were ‘leaking’ power. 

We started in the kitchen. When we moved into our house the kitchen had just a tiny ‘beer’ type fridge. We carried on using it but added a larger larder style one too. Turns out this tiny fridge, being old and inefficient, was using nearly 70 watts every hour, every day. Turning it off saved 613 kWh or £208 a year

The bigger fridge was also old and expensive to run, using 92 watts an hour. It was in need of a new thermostat too, so rather than replace the part we decided to replace it altogether with a more energy efficient model which draws just 26 watts. That saves us a further £196 a year at current prices.

Our next find came with our back-up system, dating back to the days before online backup. Despite now only being used to stream an occasional film it was still on 24/7, using up 102 watts and costing over £300 a year. That’s more than a Netflix and Spotify subscription combined! Safe to say, we pulled its plug.

The fridge and back-up system were the big easy wins, but by measuring every circuit we found others to add to our energy cost savings. One important one was anything left on standby when not in use.

This included the TV, which is friends with various other electrical boxes, and just on standby they were eating 30 watts an hour. We saved £74 a year by buying a voice controlled smart plug that links to the TV remote and disconnects the TV and associated electronics from the mains when we turn off the TV.

We fitted smart plugs to anything else that was drawing significant power while in standby so they are turned off when not needed. 

If you’re not sure which devices to check, computers and audio and video equipment are good places to look, or just measure anything that has a glowing red light even when you aren’t using it. 

Overall, we were able to reduce our base load from 541 to 233 watts, a saving of around £900 a year. Admittedly we had to buy a new fridge and five smart plugs, but you can see that rather than rushing to buy solar panels, heat pumps and battery storage, you can make savings on your energy spending by looking at the little things. Or, to paraphrase a well known saying, if you look after the watts then the kilowatts will look after themselves!






2 responses to “How to look after the watts”

  1. Corony Edwards avatar
    Corony Edwards

    This is interesting, Kate. Which smart plugs do you use?

  2. Tom Wilson avatar
    Tom Wilson

    Hi Kate. Very thought provoking. I have recently bought a “Power Meter PMB05” for around £20 from Amazon. Lots of different models available. The main draw back of this one is that when I need to reset it I have to poke a bit of wire through a tiny hole on the front ! How daft is that ? No off switch or reset switch. Anyhow, it has been quite a revelation to see how much energy is being used. I have a freezer in my greenhouse for keeping surplus veg from the garden, but now I know it is drawing aprox £2 worth a week it makes my runner beans quite an expensive item (though they do seem even more tasty when I defrost them “fresh” in January/February). So, now it is used to freeze the main harvest, and I transfer as much as I can to the house fridge/freezer as room becomes available. Tom.

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