Economic analysis of heat pump/ice storage/photovoltaics

Have you ever created a corresponding analysis?

In my very personal situation, the break-even for my PV system is about 6-7 years (just a 10kWp system without storage)

I dug up my bill from last year again. I pay 38.59 Ct/kWh, is it 36.1 Ct/kWh for you as described above? The gas price for me is 13.88 Ct/kWh. I’m apparently 2 to 4 Ct/kWh higher... which provider do you have?

With the best will in the world, I only come to 3000 € per year. You probably didn’t include basic charges in the kWh prices. But that won’t add up to 2000 € either. The ice storage sounds good in theory. But to store around 11,600 kWh of gas consumption over the summer, you will probably need a very large storage tank. You can store PV electricity in battery storages, but not shift it from summer to winter. They have too much standby loss for that. If you have space in the garden, you are probably better off with a self-built trench collector. It can’t store energy either, but in winter it doesn’t have to process frosty outside air into heat. To return to profitability: 11,600 kWh of gas after deducting chimney losses is still 10,000 kWh of heat demand, for that a good heat pump has to use 2500 kWh of electricity, and that costs you 965 €, unless you find a cheaper electricity provider. So the consumption alone is already cheaper than gas. Before you seriously switch, have a heat meter installed in the heating circuit, it measures the actual consumption more accurately than the gas meter before the chimney. With PV you can save something in the transition period, and for hot water in summer anyway. Of course, acquisition costs come on top, but you can depreciate them for your internal accounting over 20 years of use. With a 40,000 € offer price minus 55% subsidy, that adds another 900 euro per year. Therefore, switching only makes sense when the old thing falls apart, or the gas supplier shuts down its network.

Hi,

Regarding the gas and electricity prices the OP is paying. They are absurd, each can easily be 1/3 cheaper. Please switch providers. You do this every 12 months!

With an offer price of €40,000 minus 55% funding, that adds another €900 per year.

The problem is, the OP does not get 55% funding, but only 35% because the gas heating system is less than 20 years old. The offers you will get, however, have the 55% factored in, meaning they are roughly twice overpriced.
This makes it very difficult to achieve any profitability. And if you honestly assume financing costs of at least 5% (very low), it is actually over immediately...

This may change in the coming years if any government actually enforces a massive increase in gas prices. But I wouldn't expect that.

I have the same issue here with a gas heating system in a house built in 2026. You currently won't get any realistic offers. I actually hoped the funding would be stopped and then real prices would reappear, but unfortunately I was wrong.

Regarding PV - yes, do it and as quickly as possible. The feed-in tariff probably won't be available for long anymore. €25k for 22 kWp including storage was a very, very good price two years ago. That should now be somewhat cheaper, but probably not under €20k. 22 kWp also sounds like a great size. We are completely self-sufficient for about 8 months a year with 18 kWp, including an electric car!

Best regards,

Andreas

The problem is, the OP does not receive 55% funding, but only 35% because the gas heating system is less than 20 years old.

Yes, early retirement for the gas boiler does not pay off. Regarding the PV system: Recently, I was offered €1400 per kWp, as well as €510 per kWh of storage and €1500 for installation. However, it was made blatantly clear to me that my roof rafters are not suitable for PV. So for me, it was only a balcony power plant with a total investment of €500 for self-installation.