How to Clean Your Home’s Solar Panels
For so many of us, we only consider what’s involved in the upkeep of a thing once we ourselves are responsible for it. Everything from cleaning a dirty kitchen, to performing maintenance on a vehicle, to even simply setting appointments with a physician, addressing responsibilities for the first time can be both surprising and intimidating.
So by raise of hands: how many of us never thought about cleaning solar panels until personally owning them?
All joking aside, once the surprise has worn off, you’re still left with either the possibility or the reality that your panels will need a wash every now and then. That’s when the intimidation part hits you: how do you clean them? Is it as simple as cleaning windows, or do you have to be careful? How do you be careful? The last thing you need is a clean-yet-damaged panel.
So, let’s talk about it.
To Clean or Not to Clean
First, a quick existential examination. Do you need to clean solar panels? Is it just for aesthetics? Wouldn’t the rain just handle it? Would you or anyone in your neighborhood even notice if they never saw brush nor sponge?
All valid inquiries. To answer them, let’s compare solar panels against windows.
Windows occasionally get dirty, but they occasionally get rinsed off by the rain. How often either of those things happen depends on several factors, including location, weather, and climate. Areas that are drier, see more dust or pollution, or find themselves downwind of construction sites (or other activities that toss particulates in the air) will likely get dirty more often.
Conversely, places that see less rain, have increased air pollution (which can also be left behind when rain dries), or are subjected to other water sources with residue-causing additives (such as salt from a water softener, or saltwater if near the coast) will see less benefit from meteorological rinse cycles.
Now, further consider that frequent organic arial traffic (read: birds, etc.) often involves unsightly droppings that don’t typically rinse off on their own. Additionally, remember that most windows stand vertically, while most solar panels are oriented closer to a horizontal position, leading to more unwanted material collecting on their surface.
So, yes, in most cases, solar panels could stand to be cleaned, at least once or twice a year. But do they need to be cleaned?
The most extreme answer is this: if the buildup on the panels is reducing their efficiency in measurable amounts, you’ll benefit from cleaning them, or having them cleaned.
Just as clean windows let in more light and provide a clearer view of the outside, cleaner solar panels allow for more efficient collection of solar energy, leading to higher electricity outputs. Since most people who get solar installed do it because it eliminates or offsets utility costs, that might be of value to you.
Before You Begin…
Now that you’ve decided to see to those grungy panels (at least, we assume you have, since you’re still reading), let’s take a moment before we grab a ladder and a bucket of water.
First and foremost, like any maintenance work on any electrical system, be sure to disconnect it first. System designs and functionality vary somewhat, but it’s always best to be certain. Make sure the system is unplugged and, to use electrician parlance, “locked out,” possibly even with a notice instructing anyone else in the vicinity to avoid reconnecting it.
Second, if this is the first time you’ve ever done this, or these are new panels you’ve never cleaned before, check the documentation. Manufacturing manuals, maintenance guides, warranty information, etc. This will help you avoid injuries, prevent unnecessary damage to the panels, and hopefully keep your warranty intact.
Lastly, take some notes. If you haven’t done this before, you may want some before and after records of things like:
- How dirty the panels were when cleaned (which can help you determine how often it should be done)
- How much efficiency has been lost due to buildup (and how much is recovered after the wash)
- The condition of the panels (so you can keep an eye on any other repair/maintenance needs over time)
Getting Started
Now, it’s time to actually gather the supplies and put the task on the schedule.
You’ll want to plan your cleaning to make the most of the weather. Panels get pretty toasty, pretty quick (black glass under direct sunlight? No…), so choosing lunchtime on a balmy summer’s day is a bad idea. Plus, cold water on a hot panel can lead to some unfortunate and tragic results.
That said, doing it at night is a bad idea, too, for some obvious reasons. Hard to see what you’re cleaning in the dark.
What you want is clear visibility but lower temperatures, such as you might find on overcast days or early mornings in spring and autumn. Beyond that, you’ll want to avoid windy weather (again, for somewhat obvious reasons; most panels are up on the roof).
Next, choose your cleaning supplies carefully. Solar panels have a few things in common with glass top stoves: the wrong solutions or tools can damage the surface, and negatively impact performance. So opt for supplies that are less aggressive and less abrasive.
In most cases, soft bristled brushes and some mild dish soap will do the trick. When rinsing the panels down, most experts recommend using something low pressure. Pouring out a bucket, a hose with a low pressure nozzle, or similar. Avoid using pressure washers.
Depending on your location, you may also want something on hand to help with residue the water may leave behind as it dries. For issues with hard water, some diluted vinegar can do the trick, for example. Or you may just need to have a drying rag to wipe things down.
Lastly, take appropriate safety precautions. Again, panels are usually installed somewhere high, like the roof of a house. You’ll need a way to reach them from the ground, such as with an extendable cleaning brush. Or, you’ll need a way to safely ascend to clean them directly—and preferably a way to prevent a sudden and unwanted descent.
Cleaning Your Solar Panels
It might seem counterintuitive, since this is the actual part where the actual work gets done, and will obviously take most of the time and effort involved in this project. Despite those facts, it’s the simplest to explain. The approach and order of operations will vary somewhat depending on which experts you ask, but most have these steps in this order:
- Remove the loose stuff—use a sponge, soft brush, low-pressure hose nozzle, or something similarly low-impact to remove anything that’s not caked on. Avoid extreme temperatures, and temperature differentials; lukewarm water is best, and it’s best when the panels are not hot to the touch.
- Apply a gentle touch—what doesn’t come off with the first pass will probably need some carefully applied elbow grease. This is what the sponge and gentle cleaners are for. Mild soap and water, diluted vinegar, or something else that avoids chemicals that can damage the panels. When using the brush or sponge, use a wiping motion rather than a scrubbing motion.
- Repeat the rinse—this time, you’re trying to get off any cleaning residue. Wash it down well with water to remove as much as possible.
- Tidy up—faster drying minimizes residue, buildup, and other unpleasantness that undoes your hard work. A soft drying rag or a squeegee will do the trick.
If all goes according to plan, you’ve scaled the “mountain,” enjoyed the view, and returned to terra firma—mission accomplished, and injury-free.
To Clean or Not to Clean
First, a quick existential examination. Do you need to clean solar panels? Is it just for aesthetics? Wouldn’t the rain just handle it? Would you or anyone in your neighborhood even notice if they never saw brush nor sponge?
All valid inquiries. To answer them, let’s compare solar panels against windows.
Windows occasionally get dirty, but they occasionally get rinsed off by the rain. How often either of those things happen depends on several factors, including location, weather, and climate. Areas that are drier, see more dust or pollution, or find themselves downwind of construction sites (or other activities that toss particulates in the air) will likely get dirty more often.
Conversely, places that see less rain, have increased air pollution (which can also be left behind when rain dries), or are subjected to other water sources with residue-causing additives (such as salt from a water softener, or saltwater if near the coast) will see less benefit from meteorological rinse cycles.
Now, further consider that frequent organic arial traffic (read: birds, etc.) often involves unsightly droppings that don’t typically rinse off on their own. Additionally, remember that most windows stand vertically, while most solar panels are oriented closer to a horizontal position, leading to more unwanted material collecting on their surface.
So, yes, in most cases, solar panels could stand to be cleaned, at least once or twice a year. But do they need to be cleaned?
The most extreme answer is this: if the buildup on the panels is reducing their efficiency in measurable amounts, you’ll benefit from cleaning them, or having them cleaned.
Just as clean windows let in more light and provide a clearer view of the outside, cleaner solar panels allow for more efficient collection of solar energy, leading to higher electricity outputs. Since most people who get solar installed do it because it eliminates or offsets utility costs, that might be of value to you.
Before You Begin…
Now that you’ve decided to see to those grungy panels (at least, we assume you have, since you’re still reading), let’s take a moment before we grab a ladder and a bucket of water.
First and foremost, like any maintenance work on any electrical system, be sure to disconnect it first. System designs and functionality vary somewhat, but it’s always best to be certain. Make sure the system is unplugged and, to use electrician parlance, “locked out,” possibly even with a notice instructing anyone else in the vicinity to avoid reconnecting it.
Second, if this is the first time you’ve ever done this, or these are new panels you’ve never cleaned before, check the documentation. Manufacturing manuals, maintenance guides, warranty information, etc. This will help you avoid injuries, prevent unnecessary damage to the panels, and hopefully keep your warranty intact.
Lastly, take some notes. If you haven’t done this before, you may want some before and after records of things like:
- How dirty the panels were when cleaned (which can help you determine how often it should be done)
- How much efficiency has been lost due to buildup (and how much is recovered after the wash)
- The condition of the panels (so you can keep an eye on any other repair/maintenance needs over time)
Getting Started
Now, it’s time to actually gather the supplies and put the task on the schedule.
You’ll want to plan your cleaning to make the most of the weather. Panels get pretty toasty, pretty quick (black glass under direct sunlight? No…), so choosing lunchtime on a balmy summer’s day is a bad idea. Plus, cold water on a hot panel can lead to some unfortunate and tragic results.
That said, doing it at night is a bad idea, too, for some obvious reasons. Hard to see what you’re cleaning in the dark.
What you want is clear visibility but lower temperatures, such as you might find on overcast days or early mornings in spring and autumn. Beyond that, you’ll want to avoid windy weather (again, for somewhat obvious reasons; most panels are up on the roof).
Next, choose your cleaning supplies carefully. Solar panels have a few things in common with glass top stoves: the wrong solutions or tools can damage the surface, and negatively impact performance. So opt for supplies that are less aggressive and less abrasive.
In most cases, soft bristled brushes and some mild dish soap will do the trick. When rinsing the panels down, most experts recommend using something low pressure. Pouring out a bucket, a hose with a low pressure nozzle, or similar. Avoid using pressure washers.
Depending on your location, you may also want something on hand to help with residue the water may leave behind as it dries. For issues with hard water, some diluted vinegar can do the trick, for example. Or you may just need to have a drying rag to wipe things down.
Lastly, take appropriate safety precautions. Again, panels are usually installed somewhere high, like the roof of a house. You’ll need a way to reach them from the ground, such as with an extendable cleaning brush. Or, you’ll need a way to safely ascend to clean them directly—and preferably a way to prevent a sudden and unwanted descent.
Cleaning Your Solar Panels
It might seem counterintuitive, since this is the actual part where the actual work gets done, and will obviously take most of the time and effort involved in this project. Despite those facts, it’s the simplest to explain. The approach and order of operations will vary somewhat depending on which experts you ask, but most have these steps in this order:
- Remove the loose stuff—use a sponge, soft brush, low-pressure hose nozzle, or something similarly low-impact to remove anything that’s not caked on. Avoid extreme temperatures, and temperature differentials; lukewarm water is best, and it’s best when the panels are not hot to the touch.
- Apply a gentle touch—what doesn’t come off with the first pass will probably need some carefully applied elbow grease. This is what the sponge and gentle cleaners are for. Mild soap and water, diluted vinegar, or something else that avoids chemicals that can damage the panels. When using the brush or sponge, use a wiping motion rather than a scrubbing motion.
- Repeat the rinse—this time, you’re trying to get off any cleaning residue. Wash it down well with water to remove as much as possible.
- Tidy up—faster drying minimizes residue, buildup, and other unpleasantness that undoes your hard work. A soft drying rag or a squeegee will do the trick.
If all goes according to plan, you’ve scaled the “mountain,” enjoyed the view, and returned to terra firma—mission accomplished, and injury-free.