Updated in September 2026.<\/strong> A well-designed solar installation starts with your electricity consumption, not with the maximum number of panels that fit on the roof. We use high-efficiency 480 Wp panels<\/strong> as the reference for the initial estimate.<\/p>\n We analyse annual consumption, expected future use, roof orientation, pitch, shading and available roof areas. If the customer does not know the roof surface, the first calculation is based on consumption and is technically confirmed afterwards.<\/p>\n For a standard residential installation, a useful initial guideline is approximately \u20ac1 per Wp installed<\/strong>, or about \u20ac1,000 per kWp<\/strong>. The final price depends on the roof, inverter, cable route, electrical board, access and chosen equipment.<\/p>\n In Belgium, one installed kWp often produces roughly 850 to 1,000 kWh per year, depending on orientation, pitch, shading, location and system losses. A 4.8 kWp installation with ten 480 Wp panels can therefore produce approximately 4,100 to 4,800 kWh per year under suitable conditions.<\/p>\n The financial result depends on self-consumption, electricity price, injection tariff and future consumption. We show the investment, estimated annual saving and indicative payback period with all assumptions clearly stated.<\/p>\n No. East-west installations can be very attractive because production is distributed more evenly throughout the day.<\/p>\n Often yes, provided the expected additional consumption is included in the design from the start.<\/p>\nHow many solar panels do you need?<\/h2>\n
Indicative investment<\/h2>\n
Expected annual production<\/h2>\n
Savings and payback period<\/h2>\n
Frequently asked questions<\/h2>\n
Is a south-facing roof required?<\/h3>\n
Should I install extra panels for an EV or heat pump?<\/h3>\n