The median cost of a solar photovoltaic (PV) system has declined from $12/W installed in 1998 to around $4/W in 2014 — about 70% less. Do you want to adopt solar technology for all your energy needs, too, but the thought of cleaning them is keeping you away? As against popular perception, solar panels don’t demand everyday attention, at least in terms of cleaning. While it’s true that accumulation of grime can block sun rays and hamper the generation of electricity, the very fact that solar panels are made up of self-cleaning materials that minimize the accumulation of dust or water on them, is reason enough to breathe easy.
THE BIG HOWS
Now, if you must clean your solar panels, let’s first answer the two big HOWs: How often must you clean them, and how should you actually go about cleaning them?
You wouldn’t have to worry about everyday dusting-n-cleaning, especially if you have tilted panels. Let the rain do its job. Occasionally, checking for bird poop, leaves, moss, algae or airborne wastes is a good idea. If you stay in a bay area, salt deposits, too, might play spoil sport. Either of these can affect the PV panel output between 10 to 30% so getting rid of such deposits is important. Circumstantial instances prove that cleaning solar panels can actually increase their efficiency up to 10% in residential installations, and between 20- 48% in farm areas.
Coming to how should you go around cleaning these panels, is it a matter or a whole Sunday going down the drain? Not really, all you need is a couple of hours, preferably early morning or on an overcast day, once in probably three weeks, depending on your location. Think it’s a cumbersome affair? Wrong again!
There are two ways to clean solar panels — self-cleaning and manual. In case you opt for the former, simply install a nozzle that sprays soap water on the panels and cleans them like a car’s windshield wiper. For manual cleaning, bring home a cleaning kit that’d ideally comprise of a brush with multiple length handles, a wiper and liquid soap. You could even use your car cleaning materials. Now, switch off the circuit, refer to the user guide or follow the three easy steps below:
1. Mix around four tablespoons of liquid soap in a bucket of water, roughly a liter. If there is some air-borne oil deposit on your panel, for spot-cleaning first use isopropyl alcohol instead of soap-water.
2. Brush off all loose material including leaves or dust with a dry brush first. For small panels use the small handheld brush while for larger plates, use a long-handle brush. Now, dip the brush into the solution and rub it over the panels gently.
3. Finally, swab off with a wiper immediately before the soap water dries up else this will reduce the sunlight-absorbing capacity of the panels.