Solar Panels on Shaded Roofs

How shading really affects a solar array, what panel-level electronics can and cannot fix, and when to say no.

Shading is not all equal

A chimney shadow crossing one panel for an hour is a nuisance. A mature tree shading half the roof through the afternoon is a design problem. Distant shading from a hillside or a tall building sits somewhere in between and needs assessing over the year, not on the day of the survey.

What it does to a string

Panels wired in series share a current path, so a shaded panel constrains the string. Bypass diodes inside the panel limit the damage, but they do not eliminate it.

What optimisers and microinverters change

They stop one panel holding back its neighbours, and they give panel-level monitoring. They do not make a shaded panel produce like an unshaded one. Treat any claim otherwise as marketing.

When the honest answer is no

Some roofs are shaded enough that solar will not pay its way. A good installer will tell you that. If your roof is heavily shaded through the middle of the day, expect that conversation and take it seriously.

Common questions

Can I just cut the tree back?

Sometimes, though it may be protected or belong to someone else. Worth checking before it becomes the basis of your design.

What does the quote cost?

Nothing, and there is no obligation. The installer provides a free design and written quotation.

Who actually does the work?

A trusted MCS-certified installer covering Portsmouth and the surrounding area. Solar Panels Portsmouth is a quote service, not the installer, so the work, the price, the certification and the warranties are all theirs.

How soon will someone be in touch?

We aim for within 24 hours of your enquiry.