You’ve invested in a solar system, your own source of electricity designed to save you money for the next few decades. The only problem? You’ve suddenly noticed some branches hanging over your solar panels, or some leaves landing on your roof, and they’re not yours. 

Whether your neighbour has planted a fast-growing tree, or it’s simply had a growth spurt, this can cause issues for your solar investment that need to be addressed. 

Reasons you shouldn’t have trees near your solar

Trees don’t just cause issues with your solar due to overhanging branches. They can also cause problems in a range of other ways, including: 

• Trees shade your solar. The shading from even a few branches can drastically reduce your solar’s performance. A small amount of shade on even one panel can reduce that panel’s power by a third, which is replicated by all of the other panels in that string, or electrical group.
• Trees attract birds. Even a few droppings on a solar panel can reduce performance drastically. Birds can also chew through wiring, causing electrical safety issues. 
• Trees drop things. Trees, especially deciduous trees, can drop a lot of leaves, as well as flowers, sticky sap, and seedpods. All these things can cause your solar panels to get dirty and produce less energy, not to mention the buildup in your gutters, causing both flooding and fire risk. 

So we know trees are bad for solar, but what do you do if your neighbour owns the tree? Here are some ways you can deal with the issue. 

Addressing neighbouring branches hanging over your panels

If your neighbour’s tree is hanging over the fence, then in most states in Australia, you are legally allowed to remove the branches in your own yard. The one exception is if the trees are heritage listed or listed under an environmental significance overlay, in which case you’ll need to talk to your local council. 

The bad news is that you can’t control trees on your neighbour’s side of the fence. To avoid expensive legal fees, it’s best to talk to your neighbours directly and see if you can reach an agreement with which you’re both happy. If this doesn’t work, the best option is to seek legal advice. 

Often, this will come under legislation such as the Private Nuisance law, defined as “the unlawful interference with a person’s use or enjoyment of their own land or of a right connected with that land.” Either way, if you can’t reach a friendly resolution, it’s best to talk to a lawyer about your best options moving forward. 

Choosing Trees to Plant Near Solar (the Best and Worst)

If you’re planning a garden, you can also plan ahead for trees that won’t impact your existing or future solar systems. 

Some of the worst trees to plant:

• Ones that cast a lot of shade, such as oak trees, maple trees, and pines.
• Ones that drop leaves or needles, such as maple trees, oaks, and elms.
• Ones that produce sticky sap or other substances, such as pines and eucalyptus trees.
• Ones that have branches that are likely to fall, such as dead or dying trees, or trees that are located in windy areas.

Some of the best trees to plant: 

• Ones that are easy to prune, such as ficus trees.
• Dwarf trees, such as dwarf citrus.
• Hedge bushes that will grow out, rather than up, such as boxwood or China pink.

Cleaning black spot fungus off solar panels 

Leaves and branches aren’t the only problems caused by tree branches hanging over the fence. If neighbouring trees contract a type of tree disease like black spot fungus, the mould spores can land on the panels and coat them in a layer of black. This black layer will stop the sun from shining through your panels and producing energy, meaning they’ll be virtually useless. 

Smaller trees can easily be treated, but for larger trees, the cheapest option will generally be to cut them down.

The good news is that once the tree is removed, a simple clean with detergent will eliminate the layers of black spot fungus on your panels. 

Hopefully, this guide helps you decide the best way forward when dealing with neighbourhood trees causing problems with your solar. Generally, the best option is to communicate with your neighbours; it’ll be easier and cheaper, and ensure you don’t create a negative relationship which might cause further issues in future.