Solar panel configurator

The drive from Ulestraten counts towards the price: € 0,30 per kilometre, and above € 3.200,00 excl. VAT I drive for free. I only use your address for this request.

On a pitched roof the panels go on rails along the tiles. On a flat roof they stand tilted on a frame with ballast. That's different material and different work, so I always price a flat roof to measure.

The hooks that hold the panels differ per roof covering. On tiles that's standard work. Slates, thatch and corrugated sheeting I always look at first; corrugated sheeting can contain asbestos, and I don't just drill into that.

The direction decides how much power a panel makes per year. I calculate with fixed values per direction: 900 kWh per kWp facing south, 780 facing east and west and 550 facing north. One kWp is 1,000 Wp of panels.

Shade on one panel can pull the whole string down. With a little shade I include optimisers: small boxes under each panel that compensate for it. With a lot of shade I look on site at what works best.

That tells me how many panels fit at most. At the site survey I lay them out exactly; it may then be one or two more or fewer.

From your usage I work out how many panels you need to generate it yourself. If you don't know, I estimate it from the number of occupants; I'll say so clearly.

On single-phase I calculate with an inverter output of about 5 kW at most. Above that, three-phase is wiser.

That way I know your connection before I start calculating. If you don't know, I'll check it first.

Solar panels get their own circuit with their own protection, matched to the inverter. If the unit is full, it first needs to be extended or replaced.

On 1 January 2027 the net metering scheme ends. After that, power you use yourself is worth more than power you feed back. Laying more panels than you use yourself then pays less than it used to.

Then I take that into account now for the inverter and the meter cupboard.