Economic efficiency of photovoltaic system and storage

Hello dear folks,

today I would like to ask you for help (after one or two side discussions and bewilderment :) ) regarding the economic viability of a present offer. We are building new this year. We currently live in a semi-detached house with about 120 sqm of living space, the new house will have about 220 sqm.

We are both working more than 90% from home, 1 child.

Roof orientation will be: South-South-West

Electricity consumption in 2021: 3,558 kWh
Heating electricity demand with heat pump in 2021: 3,617 kWh

In the new house we will have district heating and a central ventilation system.

I have an offer from the company enersol for:

Photovoltaic system 9 kWp (is the maximum for this type of photovoltaic modules according to the dealer)
24 modules WINAICO WST-MGL GEMINI 375 heat pump

Fronius Symo 8.2-3-M 1 piece

sonnenBatterie 10 with 11 kWh

The complete installation, 1 year flat-rate insurance, substructure, delivery, registration and completion notification, acceptance, etc. is included

Price with storage: 26,296 euros gross.
Price without storage including installation without scaffold flat rate (500 euros) would be 13,447 euros gross.

Is it worth it?

As far as I have read so far: No. But surely there will be others who have more to say on the topic.
For example, I compare the offered battery with 11kWh for 13,000 EUR against the Tesla Powerwall with 13.5 kWh for 9,600 EUR. – OK, without installation, but for 3,500 EUR a electrician should definitely come.

Otherwise, a storage system that large is probably not worth it anyway. You have to fill it or empty it first. => In winter you won’t fill it up during the day and in summer you won’t empty it at night.

And in the future, the electricity will go into the electric car battery during the day anyway.

1,310 €/kWp net for the photovoltaic system is okay for the size, I would say. Not a bargain, but always questionable if you can get something better at the moment. Get the VAT back, then it should pay for itself. You just have to do the math.

Or still look around for a better offer. The return lies in the purchase ;)

Regarding the topic of storage + profitability, I think everything has been said. There are even studies on it.

The price is okay from my point of view. About 1,300 per kWp net is not little. We signed for 1,100€ two years ago. But considering the current situation, it's certainly okay. It can only go up. I would leave out the storage. It is not yet worthwhile. If you do it smartly, you will end up with about 30% self-consumption. For normal consumers, without pool and co., with heating even more. I would do it.

1,310 €/kWp net for the photovoltaic system is okay for that size, I would say. Not a bargain, but always questionable whether you can get something better at the moment.
Claim VAT back, then it should pay for itself. You just have to do the math.

Or still look for a better offer. The profit margin lies in the purchase ;)

Regarding storage + profitability, I think everything has been said. There are even studies on that.

Keyword VAT reclaim – but then I also have to do these monthly pre-registrations and pay tax on self-consumption? Does that pay off in the long run?
In general: Are there calculators on the internet that calculate everything sensibly? Including tax issues, etc.? A complete calculator so to speak.

Only quarterly now. The year of commissioning and one more, then you can get released. I think, just off the cuff. If something is wrong, feel free to correct me.

It's really not a big deal, I think it's just 3 numbers to enter online.
Over with the PV folks, there's a good Excel program for everything (Paulchen's Photovoltaic Tax), including support, available for a donation to a good cause.

VAT on direct consumption is peanuts.
I don't know what your hourly wage is, but for me, the few hours of tax stuff pay off with the VAT refund ;)

There's one from Stiftung Warentest. Or simplified as and have already calculated.
Since you don't know some parameters anyway (future electricity price, self-sufficiency rate, service life, etc.), this actually makes more sense anyway.
Better well estimated than badly calculated!