Trees and Solar Panel Arrays

The supply and installation of solar panels has increased significantly in recent years, especially in the southern half of the country. The attraction of falling costs in recent years has seen an increase in homeowners choosing to install arrays.

There are many species of tree that can grow taller than a standard residential property in the United Kingdom. Trees adjacent a solar array could present a potentially significant impact on solar photovoltaic panels or even solar thermal panels. This is exacerbated further by semi-evergreen and evergreen trees such as Lawson and Leyland Cypress. These are frequently planted as screening hedges and can produce annual extension growth in excess of a metre a year and attain mature heights of 35 metres.

Shading of Solar Panels
Most solar panels in UK residential installations will experience power reduction or loss through shade and can be overly sensitive to even partial shade even if only part of the array is shaded.

Evergreen trees retain foliage all year round and therefore could present a year round issue. Deciduous trees, whilst losing their leaves in winter when the sun is low, often present large, spreading and dense canopies during the summer months.

Installing Panels on a Shaded Roof
The installation surveyor should point out any potential problems with existing or future shading and explain to you the likely loss in generated electricity due to existing or progressive shading.

Solar Panels and the Law
There is no legal requirement to prevent or negate the shading of solar arrays by trees and this is not a legal 'nuisance' as defined in law. The one exception is the High Hedges legislation which is enacted under Part 8 of the Anti-Social Behaviour Act (2003). This provides local authorities with powers to manage complaints concerning high hedges and entered into force on the 1st June, 2005. If you believe that a neighbour's hedge is causing a problem you can take action through your local authority. However, you will need to demonstrate that you have tried to negotiate with the neighbour in the first instance.

The planned installation or presence of an existing array on either a homeowner or third party property presents no justification for the excessive reduction or removal of a protected tree and consent for such would not be granted by the
Local Planning Authority.

Trees within your ownership
You are advised to seek advice and guidance from the Council regarding any Statutory Controls, such as Tree Preservation Orders or Conservation Areas in relation to your own trees. If any constraints are present, you will need to make a formal application to the Council for consent of any tree works. Failure to obtain consent could render you liable to prosecution and a fine. The presence of solar arrays would not be a consideration with
regards to excessive tree management works.

Trees within third party ownership
If the trees are on privately owned land, you are advised to approach the landowner and discuss the issues regarding shading of an array. They are not legally obliged to undertake or agree to carry out works to mitigate the situation. However, liaison with the landowner can frequently result in a mutual agreement to carry out works, possibly with shared costs. Again, it is essential to determine if any Statutory Controls apply before undertaking any works.

Council owned trees or protected trees.
In cases where a report from a qualified engineer is presented in support of a request for works to a Council tree or a formal application for works to a protected tree, the Council may well agree to or give consent to tree works that are reasonable and good Arboricultural practice. The Council are unlikely to agree to excessive works that would result in the removal or loss of a tree or trees.

Works to Council owned trees are likely to only be carried out when resources allow and after high priority works such as those for health and safety and compliance with the Highways Act.

The council will not agree to:

  • Remove or significantly reduce tree(s) where shading of solar arrays is the sole reason for the works.
  • Undertake works where there is doubt on the cause of shading.
  • Undertake works to trees where other options for resolving the issue have not been attempted.

Further Information