Last winter season was the first season for our new heatpump in our permanent home. The first season was more of a stress test for the heatpump, as our roof isolation was not present, and much of the heating energy was wasted. This year was expensive and hopefully not representative for the years to come.
Winter season 2024
For this and future measurements I will consider the winter season to start on 01.10 and end on 01.04.
For the Winter season 2024 (01.10.2024 - 01.04.2025) we used in total 3.7 MWh of power and 629 m³ gas. At a current rate of ~0.30€/kWh and 1.35€/m³ this is about 2000€ for energy costs for the whole winter season. I’m curious how the summer months will look like, so we get a baseline for the continuous usage.
The heat pump used 3.0 MWh of the total 3.7 MWh (netto usage) we spent over the winter. I measure this directly at the socket of the heat pump with a smart plug.
Here’s how much power we used in the months. Values are rounded to the next digit in the table.
| Month | Netto usage | Imported | Exported | Produced |
|---|---|---|---|---|
| October | 371 kWh | 316 kWh | 107 kWh | 181 kWh |
| November | 801 kWh | 649 kWh | 8 kWh | 57 kWh |
| December | 838 kWh | 700 kWh | 0 kWh | 32 kWh |
| January | 915 kWh | 752 kWh | 6 kWh | 54 kWh |
| February | 600 kWh | 564 kWh | 79 kWh | 144 kWh |
| March | 233 kWh | 466 kWh | 244 kWh | 384 kWh |
This is a lot of energy spent on heating. Because our roof is not yet fully isolated, I assume that we lost a lot of energy through the cracks between the wooden boards. On some days one could feel cold air coming in - not good, but we didn’t manage to finish the isolation before. So, we need to see next year how much of a difference it makes. I have some expectations, especially because the gas usage was surprisingly very high.
For comparison, in our first house in Almere we used in winter 2020 about 952 m³ of gas (and 1.3 MWh) in a house that was heated by gas only. In winter 2021 it was 850m³. In the house in Veldhoven, where we had only a heatpump for heating we used about 2.7 MWh of power - in a place that also always felt a bit cold.
So the priority for next season is to get the roof isolated. And then we expect the power and gas consumption to go both down considerably. The first year was more of a stress test, as it was really running non-stop at high throughput. It shows that it works, but we certainly lost a lot of energy due to the bad (or better non-existing) isolation.
TL;DR
The usage for the winter season 2024 (01.10.2024 - 01.04.2025) was as follows
Total power usage: 3.7 MWh
Heatpump power usage: 3.0 MWh
Gas used: 629m³
Assumption: Excessive energy loss due to not isolated roof.