How big should a home solar system be?
In Central Europe one kilowatt-peak (kWp) of modules typically produces 850 to 1,100 kWh a year, depending on location, orientation and tilt. A household using 4,000 kWh a year would in theory need about 4 kWp — but a larger system is usually the better buy, because scaffolding, planning, the inverter and the grid connection cost roughly the same either way.
Modern modules need about 4.5 to 5.5 m² of roof per kWp. Clearances to ridge and eaves, roof windows, chimneys and shading reduce the usable area; we check this from photos, drawings or on site.
Which roofs are suitable?
South-facing roofs with a 20 to 40 degree pitch give the highest yield per kWp. East-west roofs produce slightly less per kWp but spread generation over the day, which suits a typical household. Flat roofs work well with ballasted east-west mounting.
The condition of the roof matters more than its orientation. A solar system stays up for 25 years or more; if the covering will need replacing within that time, renovating it before installation is almost always cheaper than removing and refitting the system later.
What we take care of
You have one contact from the first assessment to handover. Our crew works to a documented checklist and records every step with photos.
- Inspection of roof, covering and structure
- System design and module layout
- Installation of mounting system, modules and DC cabling
- Coordination of the grid connection with the network operator
- Commissioning, photo documentation and walkthrough