As anyone who has received a sunburn on an overcast day can tell you, much of the sun’s UV light still gets through to the earth even if there are clouds in the sky. It’s that same UV light that is mostly responsible for creating energy in solar panels. However when it really gets dark and rainy, while panels do still produce energy, they produce quite a bit less.
However, they don’t produce quite as much electricity. Here are some examples of potential panel efficiency changes:
- Cloudy & raining – 40% – 90% drop in efficiency depending on how dark & heavy the rain & clouds are.
- Heavy San Francisco fog – 15%-20% drop in efficiency
- Light San Francisco fog – 8%-15% drop in efficiency
- Age of the panels – 0.5%-1% drop per year
- dirty panels – 1%-5% drop in efficiency
So even if you live in Seattle, or the frequently foggy Richmond District in San Francisco, you can still make use of the sun’s UV rays and go solar!
As always, if you’re ready to go solar and want to start by comparing a couple of free solar estimates from local installers, please fill out our contact form and we’ll get you on our way. We’ll also send you our guide to going solar that will help you through the process.