Rooftop Solar PV Installation

Rooftop solar PV installation involves mounting panels, running DC cables, and connecting inverters on buildings.
Panels generate DC electricity as soon as they are exposed to light — they cannot be fully switched off.
DC electrical hazards are different from AC — arcing is sustained and harder to extinguish.
Working on roofs creates fall risks from edges, through fragile roof lights, and from access equipment.
The Work at Height Regulations 2005 and Electricity at Work Regulations 1989 both apply.
Panels are heavy and awkward to carry on pitched or uneven roof surfaces — manual handling risk is high.
Wind can lift unsecured panels off the roof during installation, creating fall and struck-by hazards.
Mounting rails and brackets must be fixed to the roof structure, not just to tiles or cladding.
Fire risk during installation is increased by hot work on metal roofs and proximity to DC wiring.
MCS (Microgeneration Certification Scheme) accreditation is required for installations qualifying for incentives.

Electrical danger	Solar panels are live in daylight — DC shock and arc flash cause serious burns and death.
Fall from height	Rooftop work is the leading cause of fatal falls in UK construction.
Panel handling	Carrying heavy panels on a pitched roof in wind causes falls and musculoskeletal injuries.
Fire risk	DC wiring faults cause fires that are difficult to fight due to energised panels.

Do

Don't

Install full edge protection before accessing the roof for panel installation.
Treat all DC cables and panel connections as live during daylight hours.
Use insulated tools rated for DC work when making electrical connections.
Plan panel deliveries to the roof using a hoist or crane, not manual carrying.
Secure panels against wind uplift immediately after positioning on the rails.
Check weather conditions — stop work in high winds that could lift panels.
Wear appropriate PPE including insulated gloves for DC electrical work.
Cover panels with opaque sheeting during wiring to reduce DC voltage generation.
Protect roof lights and fragile areas with load-bearing covers before access.
Follow the manufacturer's mounting instructions for rail spacing and fixing method.

DON'T touch exposed DC connectors or wiring without insulated gloves and tools.
DON'T work on the roof without edge protection around the full perimeter.
DON'T carry panels up ladders — use mechanical lifting to get them to roof level.
DON'T leave panels unsecured on the roof where wind can lift them.
DON'T assume panels are safe to handle because they look inactive — they generate DC in light.
DON'T walk on fragile roof lights or unprotected openings during installation.
DON'T install panels in high winds — the sail effect makes handling dangerous.
DON'T connect the system to the grid without completing all testing and certification.
DON'T cut corners on mounting rail fixings — inadequate fixings fail under wind load.
DON'T use water to fight a fire involving energised solar panels without specialist advice.

See also: Solar PV Installation Safety | Roof Work Risk Assessment

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