£4 a panel, minimum £40; a typical ten-panel roof £40 to £50, once or twice a year
Solar panel cleaning
Panels lose a tenth of their output to a year of pollen, bird mess and the film the rain leaves, and the manufacturers say pure water and a soft brush, nothing else. That is what we use, from a pole, from the ground or a secured ladder, £4 a panel with a £40 minimum. Spring, before the long days, is when it pays.
The installers tell people the rain keeps the panels clean, and in the first year it nearly does. By the third year there is a grey film on the glass, a stripe of lichen along the bottom edge where the water sits, and a bird's contribution in the middle of the array, and the inverter is reading a tenth down on a clear day. Pure water takes all of it off without scratching the anti-reflective coating, which a hosepipe and a sponge will, and the brush on the pole reaches a standard pitched roof from the ground.
We clean early in the morning or on an overcast day, because cold water on a hot panel can crack it, and we never walk on a roof or on the panels. Where the array is on the back of a three-storey house or behind a dormer we use a secured ladder to the gutter and the pole from there. If you have the app for your inverter, look at the reading the week before and the week after; most people see six to ten per cent back, and on a four-kilowatt system that pays for the clean in a couple of months.
Ground-mounted arrays, the panels on a barn roof and the commercial arrays on the industrial units out towards Culverhouse Cross are quoted by the array after a look at the access, and we bring the trailer tank for the big ones. Bird-proofing mesh under the panels is a job for the installer, but we will tell you if the pigeons have moved in, because the mess on the panels is the first sign.
What is included
- Pure water and a soft brush only, as the manufacturers specify
- From the ground or a secured ladder; nobody on the roof
- Lichen along the bottom edge treated
- Early morning or overcast days, never on hot glass
- A photograph of the array before and after
- A reminder text the following spring
What it costs
£4 a panel, minimum £40, so a ten-panel roof is £40 and sixteen panels £64. Ground-mounted arrays and commercial roofs quoted by the array. Once a year in spring is usual; twice near trees or a busy road. Including VAT. The prices page works a round out from the number of windows; the rounds page gives the day for your street.
Questions about solar panels
Will cleaning void the warranty?
No. Pure water and a soft brush is what every panel manufacturer specifies; detergents, pressure washers and abrasive pads are what void it, and we use none of them.
Can you clean panels in winter?
Yes, on a day above freezing, but the gain is smaller because the days are short. Spring is the time, before the panels do most of their year's work.
Your street has a day. Your house has a price.
The rounds page gives the day and the next date for your postcode; the prices page turns a window count into the figure. Send the form or a text and Lowri replies the same working day, and your first clean goes on the next round through your street.