UK rain does most of the cleaning for you. That said, panels in dusty rural settings, near busy roads, or under trees can pick up enough grime to shave a few percent off generation.
When cleaning is worth it
- Visible dust, pollen or bird droppings that don't wash off in rain.
- A noticeable drop in generation compared with the same month last year.
- After a long dry spell in summer.
How to clean safely
Ideally use a soft brush and de-ionised water on an extendable pole from the ground. Never walk on your roof and never pressure-wash panels. If you can't reach safely, book a professional clean.
Do you need to?
For most Staffordshire homes, once a year is plenty — and some systems will never need it.