ᐅ Additional meter for heating electricity tariff: yes or no?

Hello everyone,

I would like to hear your opinions on the above-mentioned question, as two electricians have different views.
Conditions:
- Ground source heat pump 8 kW with cooling function for summer
- Photovoltaic system SE+NW 16.38 kWp
- New single-family house with 193 m² (2,076 sq ft) living area

We now want to determine the size of the distribution board. Of course, it is also crucial to know how many meters I will need and how much space should be reserved for them.
One option is to go with 3+1 meters to be ready for everything. However, there is a price difference depending on whether you can leave out two meter slots and have only 1+1 in the panel.

Additional costs come from meter rental fees and usually the higher basic charges, which reduce the savings from the cheaper heating electricity tariff. If I roughly calculate this, you would need to consume quite a lot of electricity (single-family house > 6000 kWh) to benefit significantly from the lower tariff. Does anyone have a clear example calculation?

The questions are:
1. Is the heating electricity tariff generally worthwhile, and from what consumption level? If it’s currently not worth it, should space still be reserved? Who knows how the difference between tariffs will develop.
2. Can the electricity generated by the photovoltaic system be used both for self-consumption within the house (household appliances, etc.) and for the heat pump?

Thank you for your assessments. I am happy to answer any questions.

Good luck

How large is the price difference between household electricity and heating electricity where you live? This can vary significantly depending on the region. Here, it’s about 1 cent, so having a separate heating electricity tariff is not worthwhile. In the end, the savings must exceed the basic fees for the meter and the second contract; otherwise, it doesn’t pay off.

Dachshund90 schrieb:

2. Can the electricity generated by the photovoltaic system be used both for household consumption (appliances, etc.) and for the heat pump?

Yes, it can. The keyword is cascade control.

WilderSueden schrieb:

How much is the price difference between household electricity and heating electricity where you live? This can vary greatly depending on the region. Here, it is about 1 cent, so having a separate heating electricity tariff is not worth it. In the end, the savings must exceed the basic fees for the meter and the second contract; otherwise, it doesn’t pay off.

Yes, it’s possible. Keyword: cascade switching.

The well-known comparison sites currently show a difference of about 6-7 cents per kWh.

Does this cascade switching specifically apply to 2 meters?

Dachshund90 schrieb:

The well-known comparison sites currently show a difference of about 6-7 cents per kWh

Is that really the case? In my metropolitan area, there is practically no difference between "regular" electricity and "heat pump electricity." Only one provider offers heat pump electricity at a lower rate than regular electricity. This has been the case over the last 10 years as well. Region Ruhr area/Düsseldorf/Lower Rhine.

But you can easily calculate it yourself.
With a fixed charge of 200€ and an electricity consumption of 4,000 kWh, the heat pump electricity would need to be 5 cents cheaper per kWh to avoid a loss (this only applies to operating costs and does not include initial costs such as installing a larger meter cabinet).

Assuming now, for the original poster and including the large photovoltaic system, that only 2,500 kWh need to be purchased externally, the required price difference increases to 8 cents for the heat pump electricity to be worthwhile.

Therefore, I maintain my statement that installing a separate meter for a heat pump is generally not worthwhile except in individual cases.

Dachshund90 schrieb:

Does this cascade connection specifically apply to 2 meters?

Yes, otherwise you cannot prove how much electricity the heat pump uses and how much is consumed by the household. Random image from Google. The photovoltaic system first feeds electricity into the house, then to the heat pump, and finally to the grid operator.

You can simply use the totals from Z1 and Z2 to calculate the actual grid consumption of the heat pump.

KarstenausNRW schrieb:

Is that so? In my metropolitan area, there is practically no difference between "normal" electricity and "heat pump electricity." Only one provider offers heat pump electricity at a lower price. It has been the same for the last 10 years. Region Ruhr area/Düsseldorf/Lower Rhine.

But you can easily calculate it yourself.
With a €200 (about $215) base fee and 4,000 kWh electricity consumption, the heat pump electricity must be at least 5 cents cheaper per kWh to avoid losing money (only for ongoing operation, acquisition costs for a larger meter cabinet, etc., are not considered).

Assuming, as in the original poster’s case with the large photovoltaic system, that only 2,500 kWh need to be purchased externally, the 5 cents increase to 8 cents, which means the heat pump electricity must be 8 cents cheaper per kWh.

Therefore, I stick to my statement that a second meter for a heat pump is generally not worthwhile except in individual cases.

My current daily comparison on a platform shows 24-25 cents per kWh for the heating electricity tariff and 30-31 cents per kWh for "normal" electricity. Postal code is, of course, specified.