Doing a reading for my Renewable Heat Incentive has made me do a few calculations and see how the energy use in the house is going.
We don’t have a realistic winter season to look at yet (here are the calculations I made), as much of the time when the heat pump was on, we had it on full, drying out the house. I could only turn on the MVHR when the work in the house stopped, due to the dust, and so I always had at least one window open until we switched the MVHR on in April.
However we now have a realistic summer. I turned the heating off in the house in April/May (I forget the date) so the following heat calculation is just for hot water. The house has stayed quite happily at 20degrees since April despite having no heating on.
| Date | Heat meter reading | Electicity used for heatpump | Total Electricty reading | Solar generated |
| 1 Sept (approx) | 0 | 0 | 0 (May 2015) | 0 (Nov 2015) |
| 5 April | 8870 | 3406.5 | 4024 | 817.6 |
| 13 August | 10392 | 3846 | 5015 | 2215 |
So over the summer period (131 days)
We used 991 units of electricity in total (paid 14 p per unit)
- 440 units of electricity for heating (47p per day)
- 551 units for the rest of the household (58p per day)
We generated 1397 Units in solar electricity (we were paid 12.8p for – £1.36 per day)
I really cannot work out how the energy we use when the sun is shining is calculated though. Does this go on the electricity meter….
Who knows. Who cares.