As UK homeowners commit to more sustainable sources of energy, the number of homes installing rooftop solar panels reached its highest level in over seven years in 2023. However one of the biggest hesitations for installing is not knowing how much maintenance they need.

Andy Kerr, Founder at BOXT has commented:

“The cost of living crisis coupled with the race to Net Zero has resulted in increased demand for solar panels. That’s why we wanted to answer some of the most common questions consumers have about solar panels and their maintenance to help anyone considering making the switch to more renewable and sustainable energy.”

The experts at BOXT have put together a guide on solar panels, sourcing the most commonly asked questions about solar panels by analysing Google search data from July 2022 – July 2023, as well as revealing how to maintain solar panels to maximise their energy output to help anyone considering installations.

1. How do solar panels work? 

Solar panels absorb light energy using photovoltaic cells. These cells are sandwiched between layers of semiconducting material, usually silicon. When light hits a solar cell it sets the electrons in motion causing an electric current called the photovoltaic effect. This effect creates a flow of electricity that can be used to power your home.

2. Do solar panels work all year?

In short, yes. With 16,680 Google searches for the question “Do solar panels work in winter?” in the last year alone, one of the biggest concerns about solar panels is whether they work throughout the year. 

Solar panels capture their energy from light, not heat, meaning they will still function in winter months. A cold bright day actually means solar cells will produce more electricity than on warmer bright days due to the contrast in energy between the photons from sunlight and the solar cells’ electrons. The higher the difference in energy between the two particles, the more power is produced, and during colder weather the difference between the two particles is greater, resulting in increased power generation within the solar cell when the light hits it.

In addition, solar cells absorb diffused light, including light that has been dispersed by particles such as rain clouds. This means panels do not need direct sunlight to function and can generate electricity even on cloudier days. 

3. Do solar panels need to be cleaned? 

Between July 2022 – July 2023, consumers asked Google the question ‘Do solar panels need cleaning?’ 15,360 times, and the answer is yes. Solar panels convert light into power, so it is important to have a clear panel that will allow as much as light as possible to pass through. Whilst solar panels require minimal maintenance once installed as they have no moving parts, keeping them clean will optimise their efficiency and ensure long-term benefits. 

4. How often should I clean solar panels?

With a 33% increase in Google searches in the last three months alone, the frequency of solar panel cleaning is a question on consumers’ minds. 

On average, solar panels should be cleaned every six months but this depends on their positioning and location. For instance, if you live in a more built-up area where more dust, exhaust fumes and dirt can build up, wooded areas where droppings can accumulate, or your solar panels are located on a shed where leaves will need to be cleared more frequently it may be better to clean them every three to four months.

5. What is the best way to clean solar panels?

The question “What is the best way to clean solar panels?” has seen a 21% increase in Google searches in the past year. Luckily, cleaning solar panels at home is not a difficult task and can be completed whilst on the ground.

First, you need to switch off the entire solar system to ensure your safety when cleaning the panels. Next, remove any loose dirt and leaves with a soft brush with a long handle. Use a soft brush or wet a soft rag with biodegradable soap and attach this to a long-handled wiper, wiping away any residue that may have built up. Never use an abrasive soap or sponge as you risk scratching the glass. Rinse a hose over the panels for a final clean, but keep on a low setting to avoid damaging the glass. 

Most window cleaners have extendable cleaning poles which they will use to clean Velux windows and an easy way to clean your solar panels would be asking your regular window cleaner to clean your panel along with your window visit.

Before starting the process, remember the best time to clean any panels is in the early morning, late afternoon or on overcast days. When the sun is shining, any water or cleaning products used will evaporate quickly, leaving behind residue which can decrease your panels’ efficiency as much as dirt and dust.

BOXT have also shared 6 tips for maintaining solar panels:

1. Minimise potential shading

Even small amounts of shade can significantly reduce the efficiency of solar panels. Trim any nearby vegetation, remove any overhanging trees or branches and check there are no potential shading objects to ensure the biggest possible surface area of the panel is exposed to light.

2. Clean throughout the year

The more light a solar panel can absorb, the greater the electric current. Rinse down with a hose every few months, or wipe them down with a damp rag to reduce any contamination which could reduce the electricity yield. Another option is to install an automatic cleaning system which comes equipped with sprinklers to keep the surface of the panel clear.

3. Regularly inspect your panels

While rainwater is great at washing away dust from your panels, it may not be sufficient enough to remove heavier, more stubborn dirt and can cause grime to accumulate at the bottom of the panel. Check for any major blockages or debris that may have gathered on your panels at regular intervals throughout the year to make sure they are in optimal condition to generate electricity.

4. Carry out inspections after more extreme weather conditions

Solar panels are built with durability in mind and are designed to withstand extreme weather conditions. However, recording the state of your solar panels before a more significant weather event will allow you to identify any damage that may occur. This will mean you will be able to get suitable repairs to ensure your system can get back to its best.

5. Monitor performance

Solar panel systems often have monitoring software that allows you to track your system’s energy production to ensure your solar panels are functioning optimally. Monitor the data regularly so you can quickly identify any declines in performance that may suggest your panels need maintenance or cleaning.

6. Schedule a service

Small signs of wear and tear can be hard to spot for the untrained eye, but will eventually slow down your panels. Schedule a professional to inspect your solar panel system every year or two to guarantee your system is in optimum condition.