Maintaining Your Commercial Solar Panels

Like anything you install on a commercial property, even the most efficient solar panels require maintenance from time to time to stay in peak condition and provide the most renewable energy for your building. Professionals recommend that you perform cleaning on your rooftop solar panels bi-annually or quarterly. A monitoring app can be most helpful in tracking solar panel efficiency. Once you notice a dip in energy production, it is a clear indicator that it is time to clean your solar panels.

What Direction Should Solar Panels Face?

This question tends to get asked frequently because customers want to ensure they get the most out of their solar panels on their commercial building. Truthfully, solar panel efficiency lies in more than the direction your solar panels face. Other factors that affect how much power a solar panel will produce are:

• the hours of sunlight your solar panel is exposed to
• the orientation of your solar panels
• the shading of your solar panels

Plain and simple, hours of sunlight refer to the time per day your panels are exposed to the sun’s rays. The more hours they receive in sun exposure, the higher their electric output will be as more solar rays have been turned into energy.

Orientation refers to the direction your solar panels are angled. To get the most out of your solar panels, the universal rule is for your solar panels to face True South if you’re in the Northern Hemisphere to receive the most direct sunlight throughout the day. Vice versa, if you’re located in the Southern Hemisphere, it is recommended you install your solar panels angled toward True North to make the most of the daylight hours and convert as much sunlight to energy as possible for your business.

If your commercial property has any obstructions, such as trees or bushes, that block the sun from hitting your solar panels, this will impact their output. Not only will this reduce their wattage rating, but it can also cause dirt and grime to build up on the panels, which lowers their overall performance. This is why it’s important to keep your solar panels clean and make sure they are positioned in a way that maximizes their exposure to sunlight. Check with an installer about where best to position your solar panels to get the most out of your investment.

How to Wire Solar Panels?

Wiring solar panels together is called stringing. An understanding of how different configurations affect the solar array’s performance is required to do this successfully. Solar panels are like batteries because they have positive and negative terminals.

By connecting the positive terminal of one panel to the negative terminal of another, you create a series connection, and these two panels become a photovoltaic (PV) source circuit. A PV source circuit is a group of modules connected with the direct current system (or DC system) being their common connection point. 

The different wires you will need to connect are:

• The solar panel wiring to the main inverter
• The inverter cables to the batteries
• The batteries to the battery bank or directly to the electric grid

When current flows through an electrical circuit, some voltage loss occurs due to the resistance in the wires. That’s called voltage drop. It reduces the amount of power your solar array can generate. In fact, the longer the wires run, the more resistance they face.

That’s why keeping voltage drop as low as possible when planning your PV system is essential. A good rule of thumb is to aim for 3% or less, per industry best practice. If you can manage it, try to keep it below 2%.

How Long Do Solar Panels Last?

Commercial Solar panels have been known to last a long time, ideally close to 25 years. Quality solar panel installations allow PV systems to withstand all kinds of weather, from wind and rain to hail. In fact, with proper installation, solar panels can even survive hurricanes, according to the Department of Energy.

Of course, solar panels are not 100% indestructible; on rare occasions, they can suffer damage by hail, hurricanes, tornadoes, or lightning. But as long as you have a good warranty and are willing to get repairs or replacements done when needed, you should be able to maintain your panels for many years and supply your business property with clean energy for many years to come.

Ironically, heat is one of the most common things that affect the efficacy of solar panels. If the temperature reaches 77°F or 25°C, solar panels will lose approximately 1% of their power output every degree above this temperature. However, elevating them a few inches off the ground or roof allows air circulation, which can help cool them down and maintain energy production in hot weather conditions.

How to Clean Commercial Solar Panels

A buildup of dirt and debris on solar arrays can keep it from peak energy conversion performance. While rain can wash away the grime that accumulates over time, it might not be enough, especially in dry climates or solar farms that are near industrial sites where dust is prevalent. It’s always recommended to consult the manufacturer’s instructions before any cleaning takes place to avoid any potential injuries. However, if you’re confident in handling the task on your own and the conditions are safe, make sure you have the proper equipment and supplies to go about this task. Be careful when cleaning solar panels, as they can be high up or in a steep, slippery location.

• Of the equipment you will need for this undertaking, a hard hat, gloves, ladder support, and harness are recommended for anyone who plans to work on cleaning solar panels on a roof instead of from the ground.
• Next, have the solution you want to use for cleaning your solar panels. A small amount of gentle dish soap mixed with one part vinegar and eight parts water will clean glass on solar panels. Abrasive, heavy-duty detergent is not recommended for this task.

How to wash your solar panels:

• Firstly, unplug your solar panels. Solar panels are electrical equipment and should not be cleaned when turned on and active.
• Use a soft-bristled brush to dislodge any dust, dirt, or leaves from the solar panels.
• Next, use a garden hose to spray the panels clean. Use a moderate stream and be wary of using high-pressure water, as this can likely create fine cracks on the surfaces of your solar arrays and ruin their efficiency in the long run. 
• Once washed with water, use a sponge or soft cloth to clean your solar panels carefully. Be patient and take your time, as aggressive scrubbing can damage the panels with scratches.
• If stubborn spots on your solar panels refuse to come clean with just water, try using the homemade solution mentioned above. It will have a more substantial cleaning power and be less damaging to your solar panels. Be aware, though and use the solution sparingly as too much of it can damage the solar arrays.
• Finally, wipe down your solar panels with a soft cloth to dry it. It is recommended after cleaning your solar arrays to monitor their energy output. A decrease in energy conversion is a notable sign that your rooftop solar panel system may have been damaged during the cleaning process.

Checklist for Commercial Solar Panels

Regular solar panel maintenance can extend the lifespan of your system and optimize performance. Follow this sample checklist for routine upkeep:

Monthly:

• Visual Inspection: Check for any signs of damage, debris accumulation, or obstruction. Look for potential shading issues from new growth in nearby trees.
• Monitor Output: Use your solar monitoring app to track energy production and ensure consistent output.

Quarterly:

• Clean Panels: Conduct a cleaning session every three months, especially if located in dusty or industrial areas.
• Inverter Check: Confirm the inverter displays a green light to indicate proper functioning. Refer to the troubleshooting guide below if errors are observed.

Bi-Annually:

• Inspect Wiring and Connections: Check for any loose wires or corrosion that might impact the system’s efficiency.
• Cleaning: Conduct a thorough cleaning to remove buildup on the panel surface.
• Performance Review: Compare energy production with previous data to identify trends or potential efficiency drops.

Annually:

• Professional Inspection: Schedule a full professional maintenance visit to inspect all system components thoroughly.
• Shading Assessment: Reevaluate any nearby trees or structures to ensure they haven’t begun to obstruct sunlight.

FAQ

Can I clean solar panels myself, or should I hire a professional?

You can clean your solar panels using a soft cloth and gentle soap solution. However, if your panels are on a rooftop, or if you are uncomfortable with heights, it may be safer to hire a professional.

What happens if my solar panels are covered by snow or heavy dirt?

Snow naturally slides off most angled panels, but heavy dirt can impact performance. Remove snow with a soft brush and schedule regular cleanings for areas prone to dirt buildup.

How do I know if my panels are still under warranty?

Most solar panels come with a 25-year performance warranty. Check with your installer or refer to your purchase documentation for specific warranty information.

Will rain clean my solar panels sufficiently?

Light rain may help, but heavy debris, dust, or grime require a more thorough cleaning to ensure panels remain efficient.

How can I tell if my solar panels are damaged?

Reduced energy output, cracks, or unusual discoloration may indicate damage. Use your monitoring app and compare data periodically. Contact a professional if you notice any unusual changes.