FAQ
Frequently asked questions.
The key answers about solar, batteries, wallboxes and heat pumps. Your question isn’t here? Just give us a call.
Costs & prices
How much does a solar system from SOLTec cost?
Our fixed-price complete systems range from €10,990 for 5.5 kWp to €24,990 for 20.8 kWp – including panels, inverter, mounting, installation, electrical work and grid registration. Batteries, wallboxes and heat pumps can be added.
Do I have to pay VAT?
Since 2023, solar systems up to 30 kWp on or near residential buildings are zero-rated in Germany (§ 12(3) UStG), including batteries and installation. So usually no VAT applies.
Is solar still worth it?
Yes – especially if you use the power yourself. Every self-consumed kWh replaces expensive grid power (around 30–40 ct), while the feed-in tariff is much lower. Our solar calculator on the home page gives you a first estimate.
Planning & technology
How big should my system be?
As a rule of thumb we plan about 1.2 kWp per 1,000 kWh annual consumption – more with an EV or heat pump. Roof area, orientation and shading matter too; we check all of this on site for free.
Do I need a battery?
Without a battery, households typically use around 30 % of their solar power themselves, with a battery significantly more. It pays off especially if you are away during the day. We calculate both options for you.
Does solar work on east-west roofs or with partial shade?
Yes. East-west roofs produce power throughout the day – ideal for self-consumption. With partial shade we use e.g. Enphase microinverters, where each panel works independently.
Which components do you use?
Manufacturers from Europe and the USA, including LUXOR, Meyer Burger, REC and Solitek (panels), Fronius, SMA, Enphase and Azzurro (inverters), and VARTA and Enphase (batteries).
Can you extend my existing system?
Yes. We extend existing systems, integrate older systems into new ones and retrofit batteries or wallboxes.
Process & registration
How does a project with SOLTec work?
Four steps: free consultation, planning with a fixed-price quote, installation by our own team and registration with the grid operator – with one contact person throughout.
How long until my system is running?
Your system is usually ready within about 90 days. The exact time depends mainly on material availability and the local grid operator.
Who deals with the grid operator and the market master data register?
We handle all of it: registration with the grid operator, acceptance and the entry in the market master data register.
Do I need a building permit?
For rooftop solar on a residential building usually not. Exceptions exist, e.g. for listed buildings – we clarify this during planning.
Warranty & service
Which warranties do I get?
A 5-year warranty on our installation, plus the manufacturers’ warranties of 10 to 30 years on the components.
What if my system stops working?
Our 48-hour emergency service helps with faults. Call us or message us on WhatsApp.
Do you offer maintenance and cleaning?
Yes, we offer maintenance contracts and professional panel cleaning so your system keeps delivering full yield.
Do you also service systems built by another company?
Yes. We also inspect and repair systems and batteries installed by others.
Battery, wallbox & heat pump
Can I charge my EV with solar power?
Yes. Solar-optimised wallboxes like the myenergi zappi charge with your solar surplus first.
Does a heat pump go well with solar?
Very well: a large share of the heat pump’s electricity can come from your own system. We are happy to advise on current subsidy programmes for heat pumps.
Do you offer solutions for businesses?
Yes – solar for commercial roofs and open land, plus commercial storage from 36 kW to over 1 MWh to cut load peaks.