Demand Calculator – How big does your system need to be?
Correct sizing determines profitability and reliability. Our calculator gives you a first orientation.
Correct sizing determines profitability and reliability. Our calculator gives you a first orientation.
A system that is too small fails to cover your needs and becomes a daily frustration. A system that is too large costs unnecessary money and produces power that no one uses. The right sizing is the key to a solar system that pays off.
The most important factors for system size:
Before you use the calculator, here are a few reference values:
| Appliance | Typical consumption | Daily runtime | Per day approx. |
|---|---|---|---|
| Air conditioner 12,000 BTU | 1.0–1.5 kW | 8–12 h | 8–18 kWh |
| Refrigerator | 0.1–0.2 kW | 24 h (compressor ~8 h) | 1–2 kWh |
| LED lighting (10 lamps) | 0.1 kW | 6 h | 0.6 kWh |
| Water pump | 0.5–1.5 kW | 2–4 h | 1–6 kWh |
| Electric shower | 3.5–5.5 kW | 0.5 h | 2–3 kWh |
| Washing machine | 0.5 kW | 1 h | 0.5 kWh |
Rule of thumb: For every 5 kWh of daily consumption you need roughly 1.5 kWp of solar power and 5 kWh of battery storage (for off-grid operation).
For a detailed calculation including profitability analysis, break-even point and financing recommendation, use our interactive calculator:
Online calculators give a good first orientation. For exact sizing we come to you, measure your actual consumption and take local conditions such as roof pitch, shading and grid quality into account. This service is free and without obligation.
Ready to harness the power of the sun? Let's take the first step towards a greener future. Reach out to us today to explore solar solutions tailored to your needs.