Solar panels producing less: what to check
Does production seem lower than before, but the system shows no error? It is not always a fault. These checks help you see whether there is a simple cause and tell you when it is worth asking for a diagnosis.
Get a quoteWe reply within 48 h. No obligation.
What's included
A look at your case
Remotely, plus a site visit if it's needed.
A written quote
With the price, before any work starts.
Only with your go-ahead
It's your call: we only go ahead when you say yes.
Safety first
Don't climb onto the roof, don't clean the panels from above and don't touch the inverter or any cables. Everything below can be done from the ground or in the app.
Compare with what is normal for you
Compare today with a similarly sunny day, in the same month last year if the app keeps the history. In winter the days are shorter and the sun is lower, and cloud lowers production: comparing a cloudy day with a clear one misleads.
Five checks
- Is there new shade? A tree that has grown, building work, an aerial. See whether a shadow falls on the panels at certain hours.
- Do the panels look dirty? Dust, leaves or bird droppings, seen from the ground. There is a dedicated service: see panel cleaning.
- Does the inverter show an alarm? If so, see Huawei alarm.
- Does the app have missing data? Missing data makes production look lower: see FusionSolar offline.
- Has anything changed? Building work, new equipment at home or a change to the system.
What it can mean
It can be shade, dirt, a problem with a panel or a connection, the inverter limiting output, or just a period with less sun. Only an assessment tells the cases apart and, without seeing the system, we can't say which it is.
When to ask for a diagnosis
Ask for help if the gap stays on similarly sunny days, if it started suddenly or if the inverter shows an alarm. Tell us the brand and model, add app screenshots and photos of the panels seen from the ground. We reply within 48 h, assess the case remotely and, if needed, with a visit, and send a written quote with the price stated before you go ahead. See also maintenance.
About this information
These are general points, common to most systems, and they give no expected production figures: those depend on the system and the site.
Frequently asked questions
How much should it produce?
We don't give figures: they depend on the panels, the orientation, the shade and the weather. Compare with your own system's history.
Will cleaning the panels fix it?
If the cause is dirt, it helps, but panels are not cleaned from above, on the roof, without training. Ask for help to assess it.
Do I need a visit?
Not always. We start with what can be seen remotely and tell you in the quote whether a visit is needed.