This is the document with our estimated electricity usage. We’ve included the things that will not change like telephones, wi-fi, fridge-freezer. It’s difficult to anticipate future electricity use because we are building a house that will make our life very different from our life now; self sufficient in fresh water, using water recycling and heating and hot water using logs and wood pellets. To create this document I put a Maplin energy monitor on the electricals and grouped ‘sub-systems’, taking readings after 24 hours.




2 Responses »

  1. Some comments on your power consumption:

    A modern energy-saving fridge & inverter will outperform a DC fridge several fold – I am surprised by the power consumption of your existing fridge/freezer; it’s several times that of our own (off grid).
    Your computers don’t need to run 24 hours/day surely? Both the mac and Mike’s computer are consuming vast amounts in relative terms – if you look at the latest notebooks, you should be able to get equivalent performance in CPU terms for less than 20W, and when you are not using them you can shut the lid.
    New computers and energy efficient fridge/freezers are cheap compared to the long term cost of batteries.
    Don’t under-estimate lighting consumption. It’s easily measured by looking at the number of lights you have on at a time; this power will always come from your battery bank (can never be offset by PV in the way you can say running a washing machine during the day), so minimising it makes sense.
    To give you a sense of what is perfectly achievable, we live with ‘no compromises’ on 2.5kWh total consumption per *day*, including PC-based working from home.

    • Thank you so much for looking at this, we were surprised by the evil Fridge Freezer as well!
      But refrigeration via the ‘Digital Caves’ consists of two, old repurposed larder fridges kept at 9 degrees with electronic controllers that also regulate humidity with cold steam humidifiers. For the future I’ve been looking at Danfoss 12/24 volt compressors and the consumption looks much better Click Here
      Our computers are laptops, could the computer power consumption be explained by the fact that both of us work from home and we charge our phones from them and the usage quoted is for 24 hours. 2 computers @ 20 W each at minimum 7 working hours a day is .28 kwH already isn’t it?. We often work for longer than that.

      And thanks so much for the heads-up on the lighting – one person said that lighting was trivial and we shouldn’t even think about it.

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