ᐅ Solar / Photovoltaics from an Economic Perspective

nordanney schrieb:
There are special heat pump tariffs (offered by some providers). However, you need to install a separate meter and have it read regularly (which also costs extra). We decided against it because it wasn’t cost-effective.

Alright, I had just read that in passing. Thanks for the clarification.

Häuslebau3r schrieb:
Isn't it currently the case that the electricity used from the grid to operate the heat pump is subsidized or cheaper? Although that might change the calculation somewhat in the end?

nordanney schrieb:
There are special heat pump tariffs (offered by some providers). However, you have to install and have a separate meter read for that (which also costs extra). We decided against it because it didn’t make financial sense for us.

We opted for the heat pump tariff because, conversely, it probably wouldn’t have been worthwhile otherwise. Probably because in the first year, the heating phase of the screed was also included in the annual billing under the heat pump tariff—so we can only make a more accurate assessment of the actual consumption for heating and hot water in the second year.

Our heat pump tariff costs approximately 0.187 euros/kWh including tax (about 0.19 USD/kWh). Regular electricity is somewhere between 0.23 and 0.24 euros/kWh (about 0.25 USD/kWh). Our initial idea was to use our photovoltaic output to support the heat pump. That way, we would have had only one “double meter” (for regular consumption and feed-in). However, we would have had to account for most of the heat pump’s demand under the standard electricity tariff. That means every kWh drawn for the heat pump would have cost about 0.05 euros (around 0.05 USD) more. The photovoltaic production during the (extended) winter months (including, for example, November and parts of October) was/is alarmingly low (see post above) and therefore unfortunately negligible.

So, we decided to go with the heat pump tariff. However, this means we cannot use photovoltaic energy directly to support the heating via the heat pump tariff. Since the highest consumption occurs during the dark season, as mentioned, this disadvantage is manageable.

How much does the second meter cost per year? I don’t know exactly: about 50 euros (around 55 USD)? I should check — I had once downloaded a statement from Westnetz.
Assuming our annual heat pump electricity consumption is about 4,000 kWh, 4,000 x 0.05 euros = 200 euros additional cost with standard electricity. Subtracting 50 euros for the meter means a 150 euro difference when using standard electricity.
I cannot really estimate how much the photovoltaic output actually offsets the costs. In summer, it’s quite possible that the 2–4 kWh/day come entirely from photovoltaic. However, the 10–25 kWh/day in autumn, winter, and early spring are hardly supported at all.

If at some point special heat pump tariffs are discontinued or their prices approach standard electricity rates, I can still switch over.

f-pNo schrieb:
A total of about 8.7 kWh was produced. Included is a peak reaching 4.5 kW. Otherwise, the daily output ranged between 1–1.5 kW. Yesterday, the system surprised with a weak 0.75 kW.

kW or kWh?

f-pNo schrieb:

How much does the second meter cost per year? I'm not sure exactly: 50 euros? I would have to check—I once downloaded a breakdown from Westnetz.
Let’s assume our heat pump electricity consumption per year is 4,000 kWh. 4,000 x 0.05 euros = 200.00 euros additional cost with regular electricity. 200 euros minus 50 euros (meter) = 150 euros difference when using regular electricity.

The difference is not 0.05 €/kWh but rather between 0.02 € and 0.03 €/kWh if you choose a cheap supplier, and the additional meter probably costs around 5 € per month, so about 60 € per year. Since the higher consumption per meter also lowers the price for household electricity, the additional meter simply doesn’t pay off.

If you also want to do “energy supplier hopping” by taking advantage of new customer bonuses every year and switching providers annually, you can probably reduce the kWh prices even further.

Musketier schrieb:
The difference is not €0.05/kWh but rather between €0.02 and €0.03/kWh if you find a cheap supplier, and the additional meter probably costs around €5 per month (about €60 per year). And since the larger consumption volume/meter also lowers the price for household electricity, the additional meter simply doesn’t pay off.

If you also want to do "energy supplier hopping," taking advantage of new customer bonuses and switching every year, you can likely reduce the kWh prices even further.

That’s right

We are currently paying 19.3 cents per kWh (including the basic fee and the new customer bonus), and the contract is eight weeks old. For this, I don’t need a special electricity tariff for a heat pump.