Compare Solar Panels: What Does €/Wp Mean?
Why price per watt-peak (€/Wp) is the fairest way to compare solar panels, and which other specifications matter.
One panel is 400 Wp, another is 450 Wp — and the prices vary widely. How do you compare fairly? The answer is price per watt-peak, or €/Wp.
Watt-peak and €/Wp
Watt-peak (Wp) is a panel's power output under standard test conditions. Divide the price by the watt-peak rating, and you get €/Wp: the cost per unit of power output. This means a more expensive but more powerful panel is sometimes actually better value than a cheaper, weaker one. Wattuu calculates this automatically for every panel.
Check These Specs Too
- Efficiency: how much sunlight the panel converts. Higher efficiency delivers more per m² — important for smaller roofs.
- Cell technology and type: for example bifacial (captures light on both sides) or full-black for appearance.
- Power warranty: guaranteed remaining output after, say, 25 years. Quality panels typically perform well above 85% after decades.
- Temperature coefficient: how much output drops in heat. A lower value is better on hot days.
VAT on Solar Panels
Since January 1, 2023, solar panels in the Netherlands for homeowners have a VAT rate of 0%. The prices you compare are what you pay with no additional 21% like many other products.
Compare Yourself
On the solar panel comparison page, sort directly by €/Wp and filter by power, brand, and efficiency. For each panel you'll see the lowest price across all connected retailers, plus price history.