Davis Tech Tips: Defogging Your Solar Panels

Weather stations have a tough life. They are required to stand for years on end in the freezing cold and blazing sun to continually provide the critical weather data we need. Davis weather stations are built tough, but this continuous exposure does come at a cost. 

We hear from some of our customers who’ve had their stations for a while that the solar panel that powers the station tends to fog up. Many longtime users describe a whitish or hazy coating on the solar panel that does not wash off with soap and water. Some owners get worried that the solar panels will not be able to keep up with the power needs of the station after the fog has built up, but – never fear – they can! 

What causes solar panel fogging on weather stations?

To be clear, the solar panel itself is not the part that is fogging up. If you look closely, you will notice that there is a clear window in front of the solar cells. This window provides protection for the solar panel against rain, ice, and the occasional bit of flying debris carried by the wind.

Before cleaning, your solar panel housing might look like this

But as happens for all plastics, UV light will break down molecular bonds in the window over time. This is usually due to photo-oxidation, and it is unfortunately inevitable. It is not, however, necessarily a problem! Both the Vantage Vue and Vantage Pro2 were designed with enough excess capacity to overcome moderate fogging.

So, if you’re a Davis customer, you don’t need to worry about that fog – unless it really bothers you aesthetically. 

How to defog a solar panel

If you would rather not live with a foggy window on your station, there is a solution, and it is not complex: polish it out.

The “fog” is mostly on outer surface of the window, so a good rub down with a mild abrasive or buffing compound and a soft cloth will remove the worse of it. Then, rinse off the housing cover with water.

A clean solar panel housing after cleaning with toothpaste

Toothpaste (not the gel kind) and baking soda can be effective cleansers. They are abrasive enough to take off the fog without scratching or damaging the window. Polishing and buffing compounds (like you get in a headlight scratch removal kit) are also very effective to remedy UV damage.

Keep in mind that you are probably not going to get all haze off the window, but you can make it look a lot better. 

Replacing the shelter housing cover on your weather station

If you’re a perfectionist and don’t like the way your solar panel housing looks even after a clean and polish (or if you’re using your station for a high-stress application where it’s getting thrashed), you can also replace the plastic front cover. 

How can I keep my Davis weather station performing its best?

Regular proactive maintenance is key to getting the best performance out of your weather station, and it also keeps your unit bright and shiny. Our weather stations are designed so maintenance and cleaning can be done easily with materials you’re likely to have around the house, as these video demonstrate:

VANTAGE PRO2:

VANTAGE VUE:

How can I give my weather station a tune-up?

Even with regular maintenance, certain parts of your weather station will wear out (dare we say, “become weathered?”) over time. Any time you see that one part of your station needs to be replaced, the best course of action is to do a total tune-up so that you can be assured all the critical parts of your unit are working together correctly.

If your Davis weather station is starting to show its age, it’s time to pick up a complete tune-up kit to refresh your Vantage Vue or Vantage Pro2 across the board. The tune-up kit includes:

FOR VANTAGE VUE:

• Lithium battery
• Debris Screen
• Rain Mechanism (in U.S. or metric units)
• Wind Speed Cartridge
• Allen Wrench

FOR VANTAGE PRO2:

• Lithium Battery
• Rain Collector Tipping Spoon Upgrade Kit (US or metric units)
• Wind Cups
• Wind Vane
• Wind Speed Bearing Assembly
• Allen Wrench
• Door with Solar Panel (that piece that’s probably fogging up!)
• Foam insert for Access Port