Clean your solar panels

The rains are mostly gone and the sun is shining again, which means is time to put away the winter coats, clean out closets and do some spring cleaning around the house.

If you have a home solar powered system, that may mean doing some solar panel maintenance.

A solar panel “works by allowing photons, or particles of light, to knock electrons free from atoms, generating a flow of electricity”, according to Live Science.

In other words, the panel’s photovoltaic cells convert the energy in sunlight to electricity (direct current, DC), which is then converted to alternating current (AC) by an inverter. AC is the type of electrical current you use when you plug anything into a home wall socket.

The “dirt” on solar panels

While solar panels generally last for up to 30 years, through time, the glass surface may get dirty from dirt, dust, pollen, leaves and bird droppings, traffic and air pollution. If you live in an area close to a freeway, factories and airports, your solar panels may need to be cleaned more often.

The position of your solar panels may also impact cleaning, as well. A study by engineers at the University of California, San Diego found that a minimum five-degree angle helped debris to slide off the panels. That means that a mild rain rinses most of the obstructing dirt and pollen away.

But flat panels may accumulate more debris and pretty much anything that obscure light’s passage may dim the efficiency of solar energy generated by your home power system. It might even halt electricity production significantly. 

In fact, research studies conducted by the Solar Electric Power Association (SEPA), regular solar panel cleaning and maintenance can improve the efficiency of solar energy up to 30 percent. 

Google also conducted an experiment at their 1.6 MW solar farm in Mountain View, California and found that cleaning the solar panels that had been in operation for 15 months doubled their electricity output.

“When we cleaned them again eight months later, their output instantly increased by 36 percent. In fact, we found that cleaning these panels is the #1 way to maximize the energy they produce,” notes the Official Google Blog.

If you notice a drop in your solar powered system’s performance, it may mean that you need to clean your solar panels.

Often, a maintenance package is part of the contract with your solar panel installer. Cleaning your solar panels may be as easy and simple as calling them to check your solar power system. 

According to the Solar America Board for Codes and Standards (Solar ABCs) the installer should conduct an annual thorough inspection for:

• water damage at any roof penetrations
• roof drainage issues
• vegetation growth
• damage to wiring insulation
• loose or exposed wiring and connections
• signs of rodent or bird nests
• discolored or leaky pipes
• brittle, sun-baked plastic wiring insulation
• excessive cracking or wear on the inverter
• burn marks, discoloration, or broken glass on solar panels
• missing bolts
• corrosion of system supports
   

Doing it solo

If you did the installation of the solar powered system yourself, or don’t have a maintenance package, you might have to get on the roof and clean the solar panels on your own.

First, follow the procedure in your manual for shutting down the solar powered system before starting to clean.

Be careful when climbing the ladder. If you can’t do it, don’t! 

Also, check with your solar panel manufacturer as they might have specific recommendations for cleaning.

Doing it may require nothing than a light brush to loose dirt before spraying the solar panels with a good garden hose. A squeegee like the one you use to clean your car’s windshield might work as well.

However, if there is build up, avoid using soap, abrasive chemicals or metal objects, as these can scratch or smear the surface of the solar panels and damage them. Only use a soft cloth or sponge. 

In addition, avoid cleaning them in the hot sunshine, as the solar panels may become incredibly hot and pouring cold water on them may cause them to crack. Reversibly, don’t spray hot water on cold solar panels, as you may cause similar damage.

It is recommended that you clean them in the early morning or evening. Too much sun on wet solar panels can cause them to dry too quickly and smudge.

Also, don’t walk on the panels to clean them.