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Winter is Coming: How to Prepare your Solar PV System for the Winter.

January 16, 2020

This week we saw the first snowfall of the year on top of Mount Sopris. And with the chill in the air, one thing is abundantly clear: winter is coming.

It’s time to start pulling out those comfy sweaters, finding the snow shovels, and getting your PV system ready for the upcoming season. There are a couple of simple preventative measures you can take to make sure that your PV system is ready to produce as much energy as possible during those cold, short winter days.

Tilt Your Panels

The first way you can get your PV system ready for winter is to tilt your panels. Snow fall can cause a problem for your winter energy production, especially if you live off grid and need as much battery charging as possible. With grid tied systems it is not as important because you just loose a small percentage of your total year round production.

The rule of thumb is to take your latitude and add 15 degrees.

For example: Carbondale, Colorado’s latitude is roughly 40 degrees
40 degrees + 15 degrees = 55 degrees
Therefore, set the tilt of your panels to 55 degrees

If you live in an area with a larger amount of snow fall, you might want to increase the tilt up to 10 degrees more to increase the amount of snow shedding. You will lose some overall production, but the increased snow shedding will help get more power into your batteries sooner after a snowstorm.

Check Your Bolts

Winter always brings more intense storms with high winds, snow, and ice here in the mountains. All of this weather can take a substantial physical toll on your system. You want to check all of your racking to make sure the bolts are secure. If they are loose, make sure to re-torque as necessary.

It’s also important to be sure all your battery cable bolts are tight and clean. Visible corrosion leads to higher heat and higher resistance connections, making your system work harder than it needs to while wasting power.

Equalize your batteries

If you are working with a battery backup or off grid system, it is imperative that you check your charge controller and inverter settings and equalize your battery bank.
When batteries sit too long without being fully charged, it can cause a phenomenon known as Sulfation. Normally, small sulfate crystals form within batteries as they discharge. However, when batteries go without being fully charged for long periods of time, these crystals begin to grow.

Large sulfate crystals can harden and decrease the usable material in your battery. This causes the potential to permanently damage your battery and shorten the useable life.

In order to combat sulfation, it is important to equalize your battery. This means periodically overcharging your battery to get rid of the larger sulfate crystals, and maintain your battery life.

• If you use your battery on a daily basis, you should equalize once a month.
• If you use your batter more sparingly, you should still equalize a minimum of four times a year.

Finally, it’s very important to check and add distilled water AFTER you equalize your batteries. The overvoltage charging (for 2 hours or longer) boils the acid and water electrolyte mix, helping knock off the sulfite crystals from the lead plates. It also consumes some of the distilled water. As long as your plates are covered at the beginning of the EQ charge, it’s much cleaner to add water after the batteries have been equalized.

• Be sure to take adequate safety precautions
• Don’t equalize sealed batteries
• Wear eye protection – a full face shield is the best
• Wear acid resistant gloves and old clothes – acid eats holes in cloth.
• Have a mixture of baking soda and water nearby to neutralize any acid
• Use insulated tools to prevent short circuits while checking the battery bolt torque

Just remember, professional help is always a phone call away!

If you need any service or maintenance work done on your PV system or if you are interested in learning more about solar for your home or solar for your business contact one of our solar consultants at (970) 963-1420.

Steve Haines, Residential Solar Consultant and Off Grid Specialist