I have no idea how suppliers do their bill forecasts and monthly payment calculation but Mystic Meg could do a better job.
My last 3 monthly bills for June, July and August have been £125, £115, £118. Yet So Energy has just estimated my annual usage at £1204, or £100 per month which is less than I have used in the lowest 3 months with a slightly lower tariff.
With that in mind I have tried to do a better forecast. The data are a bit thin because we have only been living in the house since early April.
Fortunately I have a separate meter on the heat pump, and in July and August when we had no heating on that effectively gives me my domestic hot water (DHW) usage of about 2-3 kWh per day. I also know the total heat pump usage so I can infer my non-heating, none-DHW consumption. I have then applied some seasonality to the heating, and a little bit to the DHW and the 'other' to allow for more use of lights, cooking, and winter baths!
The result is an annual consumption of 8127KwH, current cost £2,990.
41% - heating
12% - DHW
47% - everything else.
"everything else" includes the MVHR (ventilation system) at an assumed £400 per year. Just before I rushed to turn it off and open some windows, I remembered that it recovers heat from used air and the energy recovered is more than the energy used.
I admit I was hoping for a better result financially but the kWh figure doesn't look too bad - it's the tariff. All electric of course. In the draughty old bungalow we knocked down, which had about half the living area, in 2013 we were using 7000+kWh of electric and over 27000+kWh of gas for heating!
Makes me ponder what we are doing, and what we can do, regarding climate change.
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