Solar panel in rainy season

Do solar powered street lights work when it’s cloudy or raining?

Commercial solar street lights can perform rain or shine. And you are right to assume that your solar panels will collect less energy on a cloudy day. But it’s not as bad as you might think. Clouds reduce the amount of direct sunlight, but at the same time, reflect light. The reflected light increases the amount of diffuse light energy.
Do solar powered street lights work when it’s cloudy or raining?

Rain actually has a benefit. Although you won’t generate peak power on a rainy day, your panels will get a healthy shower. Rain rinses away debris and dust, resulting in greater efficiency. This is especially true for the hydrophobic panels Fonroche uses. The coating repels water so that droplets roll off the sloped surface, carrying dust & dirt with them. It prevents spots, similar to the way the rinse-aid in your dishwasher does.

Designing Industrial Street Lights to Withstand Cloudy Days

How can you make sure that your solar powered street light will have enough energy for a cloudy or rainy day? Think about it like having enough money for a “rainy day.”

If you have money in your savings account when that rainy day arrives, you can draw on those reserves. In a solar lighting system, that is like having extra battery energy in reserve.

But how to replenish that reserve? If it’s a bank account, you need to make more money than you spend, so you can replenish the account. In a solar lighting system, you need to collect more energy than you need to use each night. This provides a surplus to refill your battery and allows you to keep the lights going strong.

This is a balancing act. If you don’t have a battery reserve, your system could run out of energy in a day or two. If you can’t generate more energy than you need each day, you will not be able to replenish those reserves after you tapped them.

The good news is that you don’t have to guess. Top solar powered solar lighting manufacturers, like Fonroche, have methods to right size your systems. They use recognized, third-party meteorological data. Then they analyze the data to understand how much energy you will need to generate and store for great reliability.

Not All Solar Lighting Systems Manage Cloudy Days the Same Way

Many off-the-shelf, consumer-grade solar street lights work on a one-size-fits-all basis. Usually, the panels and battery packs are smaller than for commercial lighting systems. They then adjust the light level based on the amount of energy it the product can collect and store. If you don’t live on the equator, this light level is likely to be much lower than advertised. Going back to our bank account example, you’ll may survive, but not well. You’ll have little saved (battery storage), little income (energy generated), and little to spend (light at night).

Advanced solar powered street lights have enough energy to support specified light levels in worst case conditions – rain or shine.
Have a solar lighting project? We’re ready to provide an energy analysis, photometric design, and configuration for you. There’s no charge or obligation. Contact us to get started.