Can Trees Affect My Solar Panels? 

Solar panels in Ireland are on the rise. As of 2023, around 60,000 residential properties have been fitted with rooftop installations. Hundreds more are turning to renewable technology every week, with SEAI grants making PV technology more accessible than ever.  
However, there’s still some resistance to the idea of solar power. One common argument is that wooded surroundings and too much shade render solar panels ineffective. However, this is far off the mark. In fact, even rooftops in the most wooded areas can benefit from solar panel installations.  

What Happens if Solar Panels Are Shaded by Trees? 

Many of us dream of living in a home surrounded by nature. However, if you live in a fairly rural corner of the country and are thinking about solar panels in Waterford or elsewhere, you’re probably wondering whether the technology and your surroundings are a good fit.  
While solar panels will produce more electricity when they’re exposed to direct sunlight, living in a property shaded by trees doesn’t make them impractical. If you’ve ever wondered ‘Do solar panels work when it’s cloudy?’, the same reasoning can be applied here. That being said, you need to think carefully about your surroundings, as an impaired panel can limit the efficiency and power output of the entire PV system.

“If you shade a 10% portion of one panel in a ten-panel string, you will possibly half the output of the entire system. This is because the negative effects of panel shading pass from panel to panel,” said Martin Desmond, Managing Director at Wizer. The primary fix for this is discussed below and is a technology-based solution, but there are more that people should take note of.

So, are solar panels worth it in Ireland if your home is surrounded by trees? The answer is yes, and there’s a lot you can do to make them more effective, even if your system will be left in the shade. The top answer for dealing with shade on your solar PV panels is a device called an optimiser.  


An optimiser is a gadget about six inches square and an inch thick with a positive and negative cable that integrates with the panel wiring while the device itself is mounted onto the panel frame which is super convenient. When a panel has shading on it and an optimiser fitted, the negative effects of this shading are not passed on to any of the other panels in that string. 

Optimisers are most frequently used around chimneys or any protrusions from the roof for the panels closest to the chimney to limit the effects of the shading when it occurs. Optimisers can also be used strategically to enable the largest systems possible in the domestic scenario. 18 panels are the limit for most systems at 430 watts per panel, but with optimisers on every panel, you could have up to 24 panels, albeit at the extra expense of 24 optimisers, about €1700 at today’s rates. 

Keep Trees Trimmed and Pruned 

Removing trees from around your property might be an option for some. However, if you’re considering solar panels in Dublin and your home is shaded by trees from a neighbouring garden, this won’t be possible. That being said, you can carry out some minor pruning to minimise the impact of shade. Target branches that are casting the biggest shadows to ensure they receive as much sunlight as possible.  

Think About Panel Orientation 

If removing trees isn’t an option, you can overcome the issue of shading by rethinking the orientation of your solar panels. The positioning of trees is also an important factor. You need to think about how many shadows are being cast during specific parts of the day. 

For example, if you want to maximise the efficiency of solar panels in Limerick, a south-facing orientation is best. A good PV installer should help you assess the position and height of trees and advise on the best solar panel orientation for your needs. An unshaded northern aspect may produce more than the ‘perfect’ south with shading. 

Don’t Forget About Seasonal Changes 

Just because trees are a problem during the summer months, doesn’t mean they’ll be a hassle during the winter. Come autumn, deciduous trees begin to lose their leaves to preserve energy. This means you’ll have fewer shadows to contend with and your PV system will generally perform a little better.  

Choose Efficient Panel Technology 

Thinking about solar panels in Cork? This part of the country receives an average of almost four hours of sunshine every day. This might not seem like a lot, especially if you’re surrounded by trees, but solar panel technology is becoming increasingly efficient.  
The best systems can produce a surprising amount of energy, even if they’re only exposed to a few hours of indirect sunlight. How long do solar panels last? Newer designs tend to come with extended warranties of 25 years or longer. While performance can dip slightly over time, it’s expected and factored in with accuracy and certainty, that most panels will continue to operate at 80% efficiency long after the 30-year warranty period is over.  

Clean Your Solar Panels 

While older solar panels need irregular (every 5 years) maintenance to perform optimally, newer systems are far less demanding. It’s a good idea to bring in professionals from time to time to ensure all those electrical components are working. In electrical contracting this is known as a ‘Periodic Inspection’ and is recommended for any plant and equipment which works such long duty cycles like solar PV but you can perform casual maintenance yourself.  
Even if you don’t live in a home surrounded by overhanging trees, foliage and other debris can end up covering your panels if you’re not careful. “This can be more of a problem during autumn, or after windy weather,” said Martin Desmond. “However, understanding how to clean solar panels or working with a professional team will ensure your system always works efficiently. Make sure you’re removing any debris regularly to ensure panels are receiving as much sunlight as possible.” 

Will Trees Make My Solar Panels Ineffective? 

Provided you evaluate your surroundings before committing to solar panel installation, a PV system can still prove effective, even in a wooded area. New PV panels are incredibly efficient, making them a good option, even if they receive relatively little direct sunlight. You can increase the energy output of your system by pruning any nearby trees. 

What’s more, an experienced installer will be able to recommend the best orientation for your surroundings. Occasional maintenance and removal of any debris will also prevent deciduous trees from posing too much of a problem.  

Looking to Switch to Solar Energy? 

Leafy surroundings don’t have to be a barrier to the benefits of solar energy. Cost-effective and incredibly reliable, a PV system can help you reduce your energy expenditure and embrace a more sustainable way of life. 

If you’re looking for a greener alternative to carbon-fuelled electricity, speak to the team at Wizer Energy today. Since 2015, we’ve carried out more than 2,000 domestic solar panel installations. 

Or maybe you are looking for sustainable energy solutions like EV chargers? Speak to us about installing a Zappi charger in Ireland.  You can arrange an online quote today. Alternatively, give us a call at 087 7530066

Author Bio

Slaven Litera

Having worked as a high-voltage power technician since 2007, Slaven Litera is Wizer’s Director of Operations. With over 15 years of experience in both commercial and domestic high voltage systems, Slaven made the transition to renewable energy in 2017. During his tenure as the lead engineer at one of Ireland’s biggest solar panel installation companies, Slaven provided end-to-end services. From pre-installation site reviews, to full commissioning and testing of new power systems, Slaven has done it all. In fact, throughout his career, Slaven has overseen and installed over 1000 individual solar PV installations amounting to over 1.2MW of solar generation! Holding electrical qualifications in multiple European countries, he continues to expand his knowledge in renewable energy sources. As Wizer’s Director of Operations, Slaven’s highly driven nature is the force behind creative and “out of the box” solutions at Wizer. Since his experience is so diverse, there’s virtually nothing he hasn’t seen before!

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Wizer Energy Ltd is a reliable, industry-leading solar panel provider in Ireland with a wealth of experience. 

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