In my research over the past few weeks, the delta between heat pump electricity and household electricity has shrunk somewhat. In my region for new contracts to about 6 ct (30 vs. 36 ct/kWh). However, there are still tariffs where the base price is 45-70 €/a (gross). So the meter pays off from 750-1200 kWh/a onwards.Good choice! With these prices, a second meter for heat pump electricity is not worth it.
Our first half winter (and spring 2021) for evaluation is almost over. I will report. For Nov-Jan it is certainly not so helpful, but in Feb (when I still had to wait a few weeks for the C19 sick electrician) there were 2 weeks of nice sunshine. And also in December there were 5 days with 14-19 kWh, where a few kWh already go to the heat pump. Of course, it is only a small share of the demand. March/April and September/October are better in that regard.We have that too, but in winter it feels like a drop in the bucket. In good winter months, we get 10% from the photovoltaic system and 90% from the grid; in bad months, sometimes only 6/94. Overall, about 14% of our energy for the air-water heat pump comes from the photovoltaic system, but that also depends on the summer months and the energy management, which further heats the domestic water when there is photovoltaic surplus.
We benefit much more from photovoltaic in summer, as it can be used for the air conditioning. Of course, it can look different if you have a significantly larger dimensioned photovoltaic system.
Addendum on costs. You can already see this somewhat here. The heat pump is for heating and hot water. Since there is no separate meter for the heat pump in photovoltaic supply, I have to deduct its consumption. There can currently (due to de-icing with and without heating element) still be an error of 5-10%.[ATTACH alt="1640878090841.png"]68250[/ATTACH]
I’ve also attached a screenshot of our numbers here. January has to be excluded because our SHM was only installed at the end of the month. Even a few sunny days in the winter months usually don’t lead to huge jumps; in our case, the share of photovoltaic energy in the heat pump energy fluctuates between 6-10% in the winter months. On an annual average (see screenshot), we reach 14, but that is because in summer we specifically convert photovoltaic electricity into hot water via the SHM instead of feeding it into the grid.
We currently only have 4.55 kWp. How much photovoltaic capacity do you have?
But we currently only have 4.55 kWp. How much photovoltaic do you have?
Our system has 6.6 kWp SSW with a 38° roof pitch (good for winter sun, where 4.2 kW are still achievable).