![\"Cleaning](\"https:\/\/www.solarquotes.com.au\/blog\/wp-content\/uploads\/2020\/01\/cleaning-dirt.jpg\")
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Lately, Australia has been having a bit of a problem with bushfires.\u00a0 You may have noticed.\u00a0 It’s been on the telly.\u00a0 Also, there’s a good chance you’ve been spluttering on vast clouds of smoke blowing across the country.\u00a0 Smoke and fine ash from the fires can travel thousands of kilometers before settling and most of us now have a fine layer of soot on our solar panels, while those nearer to fires may have a thick layer of ash.<\/p>\n
The good news is while this may reduce the output of your solar power system, provided it wasn’t hot ash or burning embers it won’t do your system any harm.\u00a0 You can wait for rain to wash the ash away or clean it off with a garden hose.\u00a0 But if there is fire in your area or your roof has been exposed to burning embers then the situation is more serious.<\/p>\n
Here’s a summary of what to do when it comes to bushfires and solar systems:<\/p>\n
If you’re reading this article because a maelstrom of fire is approaching your home and you want to know how to quickly shutdown your solar inverter, there should be instructions on your inverter you can follow.\u00a0 But if you don’t feel confident you’ll get it right, then just go. There are worse things in this world than not shutting down your inverter and a maelstrom of fire is one of them.<\/p>\n
But if things aren’t that urgent, then you’ll have time to read below, where I go into more detail starting with the common bushfire related problem people have, which is sooty panels.<\/p>\n
![\"Bushfire](\"https:\/\/www.solarquotes.com.au\/blog\/wp-content\/uploads\/2020\/01\/fabulousmonster.jpg\")
This is soot from Australian bushfires that has fallen on a New Zealand glacier. Chances are there’s considerably more on your solar panels. (Image Source: I stole this from The Guardian, but they appear to have stolen it from Fabulousmonster, which is the only kind of monster I’d expect to find in New Zealand.)<\/p><\/div>\n
Almost every Australian home has been exposed to bushfire smoke.\u00a0 We’ve gotten off lightly here in Adelaide, but roughly 20 million people have had it worse.\u00a0 It has left a film of grime on most solar panels.\u00a0 If you run your fingertip along the outside of a window and it gets blackened with soot, chances are there’s more on your panels.\u00a0 The good news is a thin layer won’t have much effect and if you check your solar inverter there’s a good chance you won’t notice any difference in output.\u00a0 Unless you are desperate to get every watt-hour you can out of your panels, there’s no need to do anything and you can wait for rain to wash it off.<\/p>\n
If there is a noticeable decline in solar energy output or you can simply see there is a lot of ash on them, then you can clean it off with a hose, provided you do it when the panels aren’t hot from being in direct sunlight for hours.<\/p>\n
![\"Bushfire](\"https:\/\/www.solarquotes.com.au\/blog\/wp-content\/uploads\/2020\/01\/burntoutscrub.jpg\")
A 6mm fire went through this scrub. That is, only things around 6mm or less in thickness burned.<\/p><\/div>\n
You can just clean ash off solar panels<\/a> with a hose from the ground.\u00a0 I don’t recommend going up on the roof because because I figure even if there is only a tiny risk of a fall, why take the chance?\u00a0 It’s a lot easier to do it from the ground and I’d much rather be safe and lazy than gung-ho and in hospital.\u00a0 There’s also not much point in going up on the roof to give the solar panels a good clean when they’re likely to have more soot dumped on them before the summer’s over.<\/p>\n Sudden changes in temperature aren’t good for solar panels so it’s best not to spray them off when they’re hot.\u00a0 Early in the morning or after sunset is a good time.\u00a0 The graph below, which I pulled from this paper<\/a>, suggests there will be little increase in panel temperature two hours after sunrise and that they will have cooled off by sunset:<\/p>\n This is for north facing panels.\u00a0 East facing panels will warm up sooner while those facing west will cool down later, so you might want to wait at least 20 minutes after sunset before cleaning them.<\/p>\n The hose water should fall on the panels like rain.\u00a0 If you have high water pressure, don’t hit them with a single powerful stream.\u00a0 High pressure could damage the seal between the solar panel’s glass and its aluminium frame.<\/p>\n Just gently spraying them with water should be enough to wash off soot.\u00a0 If you can see there is still dirt stuck to the panels, leave it to soak for maybe 10 minutes and then let more water fall on it.\u00a0 If doing this a couple of times isn’t enough to clear the ash away you can consider getting the panels professionally cleaned.<\/p>\n If you have no water to spare and need the extra solar energy, you can clean panels with a soft broom.\u00a0 But this does violate my don’t go up on the roof rule unless you’ve got really long arms or something.<\/p>\n Unless something weird is going on, you can expect soot to be evenly distributed over your panels.\u00a0 An even layer of grime will reduce output, but it won’t otherwise negatively affect panels.\u00a0 But if dirt is unevenly distributed, say you’ve had a little rain that was enough to make the soot streaky but not wash it away, that is worse for the panels than an even layer.<\/p>\n The reason why is the cleaner solar cells will produce more energy but their output will be dragged down to the level of their dirty neighbours and the extra energy will be lost as heat, raising the temperature of the panel.\u00a0 This is not a disaster and uneven soot should not be a significant problem for any solar panel of decent quality.\u00a0 But uneven patches of dirt will mildly increase the wear and tear the panels suffer and so it gives a little extra incentive to clean them off.\u00a0 But I wouldn’t be very concerned if you don’t get around to cleaning them.<\/p>\n If there is a fire in the area and a risk of your roof being exposed to burning cinders, you should shut down your solar power system as a precaution.\u00a0 Note that under catastrophic bushfire conditions burning embers can travel up to 10 kilometers<\/a> in front of a blaze, which is just nuts.<\/p>\n Shutting down solar systems is important as burning embers can damage wiring and create a fire risk.\u00a0 It would be pretty tragic if bushfire embers didn’t set your home on fire but damaged solar system wiring and a DC arc did.<\/p>\n![\"Solar](\"https:\/\/www.solarquotes.com.au\/blog\/wp-content\/uploads\/2020\/01\/The-PV-module-temperature-and-electrical-power-distribution-together-with-model-inputs.png\")
<\/p>\nBe Gentle With Your Hose<\/h2>\n
No Water?<\/h2>\n
![\"Bushfire](\"https:\/\/www.solarquotes.com.au\/blog\/wp-content\/uploads\/2020\/01\/missedme.jpg\")
<\/p>\nPatchy Soot Is A Little Worse<\/h2>\n
Fire In Area? Shut Down Solar System!<\/h2>\n