BrightGridShading is one of the most important factors to assess before installing solar panels. Trees, chimneys, dormers, neighbouring buildings and other roof structures can reduce the amount of sunlight reaching an array.
Why does shading matter?
A solar panel produces less electricity when sunlight is blocked. The effect can vary depending on the position of the shade, the time of day, the season and the electrical design of the array.
Common causes of solar shading
- Trees and vegetation
- Chimneys
- Dormers
- Nearby buildings
- Roof structures
- Satellite equipment
- Temporary construction
- Future tree growth
Can optimisers help?
Module-level power electronics can sometimes reduce the impact of uneven shading by allowing individual panels to operate more independently. Whether they are worthwhile depends on the roof and the proposed system design.
How should shading be assessed?
- Identify all current sources of shade.
- Consider seasonal changes.
- Assess morning and afternoon shading separately.
- Consider future tree growth.
- Model the roof using appropriate solar design software.
- Compare alternative panel layouts.
Do not estimate shading by eye alone
A professional solar design should consider the movement of the sun and the expected shading profile rather than relying only on a photograph of the roof.
Check your roof for solar shading
Get a system design based on your actual roof orientation, usable area and shading conditions.
Explore SolarFrequently asked questions
Can solar panels work with trees near the roof?
Yes, but the expected shading should be modelled before installation. Trees can reduce generation and may create more shading as they grow.
Are solar optimisers worth it for shaded roofs?
They can be useful on some shaded or complex roofs, but the benefit depends on the exact shading pattern and system design.
Should I remove trees before installing solar?
Not necessarily. A solar designer should first assess the actual shading impact and consider alternative panel layouts or electrical solutions.
Daniel Mercer
Solar Design Engineer at BrightGrid Energy
