Gulls, pigeons and looking after panels in Southport

Why birds move in

The space under a roof-mounted array is only a hand's depth, but it is sheltered from wind and rain, warmed by the panels and hard for predators to reach. Feral pigeons are the usual tenants; gulls more often nest in the open on flat roofs and chimney stacks, but they foul panels from above and will use any ledge an array creates. In a town where gulls are part of the sea front, it is worth planning for birds from the start.

The costs of letting it happen are practical rather than dramatic: droppings and nesting material collect in gutters and on the slates, the noise carries into a loft bedroom, and debris can trap damp against the roof covering. Cables under the array can be pecked or chewed.

Mesh, fitted early

The standard fix is a galvanised or plastic-coated mesh that runs round the edge of the array, closing the gap between panel and roof. The better systems clip to the panel frames, so they can be lifted off for a roof repair and nothing is drilled into the slates. Ask for mesh as a separate line on the quote, so you can decide on it. Many owners add it at installation, while the scaffold is up, because fitting it later means paying for access again.

Spikes along the top edge of an array are less useful: pigeons get underneath, not on top.

If birds are already nesting

All wild birds, their nests and their eggs are protected. Under the Wildlife and Countryside Act 1981 it is an offence to intentionally take, damage or destroy a wild bird's nest while it is being used or built, or to take or destroy its eggs. Government guidance says to avoid harming birds and to use measures that do not kill or injure them first. In practice that means waiting until a nest is no longer in use, typically after the young have fledged, then having it cleared and the array meshed before the next season. A pest-control firm or your installer can advise on timing.

Cleaning

On a pitched roof, rain keeps most panels clean enough. Dirt matters more on a low-pitched array, where it collects along the bottom edge. Clean when:

• you can see droppings, lichen or a line of grime along the lower frames;
• your monitoring shows output well below the same month last year with similar weather.

Use soft water and a soft brush, from the ground with an extending pole or by a firm with proper access. Avoid detergents unless the panel maker allows them, never use a pressure washer, and never walk on panels or climb onto the roof yourself.

The rest of the upkeep

1. Watch the monitoring. Most inverters report output to an app. Compare each month with the year before; a sudden drop is the early sign of a fault.
2. Look at the inverter now and then. A warning light or error code is worth a call to the installer while the workmanship warranty runs.
3. Keep the paperwork together. The MCS certificate, the network operator's acknowledgement, the warranties and the electrical certificate are needed for export payments, for any claim and when you sell.
4. Plan for an inverter. Panels typically outlast the first inverter. Budget for one replacement in the system's life.
5. Check after storms. High winds on the coast can lift loose slates around an array; a look from the ground after a gale costs nothing.

Read on

• From quote to switch-on
• Slate roofs
• Finding an installer
• FAQs

Sources for this page

1. GOV.UK (Natural England and Defra): wild birds, protection and licences
2. Wildlife and Countryside Act 1981, section 1 (protection of wild birds, their nests and eggs)
3. MCS standards and tools library (MIS 3002, MCS 012)
4. Renewable Energy Consumer Code (RECC)