What is watt-peak (Wp)?
Watt-peak is the measure of a solar panel's power. What it means and how to convert it into yearly output.
Watt-peak (Wp) is the maximum power of a solar panel under ideal test conditions. It tells you how strong a panel is, not what it produces over a year.
What does watt-peak mean?
Watt-peak is the power a panel delivers under standard test conditions: a fixed amount of light and a fixed temperature. It is a reference value that lets you compare panels fairly. A 450 Wp panel is stronger than a 400 Wp one.
From watt-peak to kilowatt-hours
Wp is about power, kilowatt-hours (kWh) about energy generated over time. In the Netherlands a panel produces roughly 0.85 to 0.9 kWh per Wp per year. That takes you from the wattage on your roof to an estimate of yearly output.
Why it matters in your quote
More watt-peak per panel means you generate the same with fewer panels, handy on a small roof. On a large roof, price per watt-peak often weighs more. We pick the wattage that fits your roof and use.
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