ᐅ Photovoltaic System – Rough Cost Estimate

Hello,

my question is a bit general and probably there is no exact answer. I have a mid-terrace house that is now 28 years old. One roof surface faces south, which I think is suitable for a photovoltaic system. By chance, I saw an offer at a Swedish furniture store for a photovoltaic system (4 kWp) including storage and installation for around 12,000. I always thought something like this would be much more expensive. Our current electricity consumption is 2800 kWh/year, and at some point the old gas heating system will certainly need to be replaced, possibly by a heat pump. Now I wonder: is this price realistic for a photovoltaic system with everything included? I guess scaffolding is needed, or do they maybe install it through the roof window using a harness?

Without knowing which components are installed and the exact on-site conditions, I would consider $12,000 for 4 kWp to be excessive. If you hadn’t mentioned a Swedish furniture store, I would have guessed en*al as the provider.
For a small system, I would set $2,000 per kWp as an upper limit. $3,000 per kWp is beyond unreasonable.
We paid $25,000 for a 12 kWp system spread over three roof sides, using high-quality components, an 11 kWh battery storage, and 65 metal roof tiles (each costing €30). That equals just over $2,000 per kWp. Without the battery and special extras, we would have been at $1,400 per kWp. The system was commissioned in February 2024.

Purchased in December 2023.
11 kWp with 10 kWh Huawei battery storage and inverter. Go-e charger, controller, and wallbox.
Complete for 19k. Baden-Württemberg.
I think it might be possible to get it a bit cheaper nowadays.

Ok, thank you very much for your assessment. As I said, I still have very little knowledge about this topic. How large should the system be? Is there any estimate? We consume about 2700 kWh/year. Perhaps a heat pump could replace the current gas heating at some point. We don’t have an electric car, and I don’t see that changing for us in the near future. So, I don’t need a wallbox for now, and it could always be installed later.

I would personally base the size of the system on several factors, with the most important being the payback period.
However, profitability is really a balancing act. The system must operate without faults for many years, and many people tend to overlook the operating costs of the system.
By now, I have come to say about our own system that we only have it because 1) we could afford it, 2) we received a small subsidy, and 3) thanks to the heat pump and recently the electric car, we can maximize self-consumption and are somewhat protected from market price fluctuations.
On the other hand, there are insurance costs (proportionally included in the home insurance), the risk of component failure. Even if this happens within the warranty period, the solar power will likely be out of use for many weeks or months until replacement parts arrive or the claim is approved. And last but not least, the increased effort required for repairing something on the roof, if needed.
Personally, I would do it again, but I can understand perfectly well if someone thinks this is an overly optimistic calculation. In most cases, it probably will be at first.

The size of the photovoltaic system should be limited only by the available space on the roof.