Common solar panel problems

It's very unlikely that solar panels will stop working, which is why they usually come with a generous guarantee. This is mostly because they don’t contain moving parts, so there’s no risk of break down or the need for replacements. But that doesn’t mean they’re indestructible or won’t develop the odd fault.

So, what are the biggest problems with solar panels, and the systems they feed? Let’s delve into the usual problems with solar panels, as well as how to prevent solar panel damage.

9 solar panel issues to watch out for

Below we’ve put together the most common problems with solar panels, as well as how to avoid them so you get the most out of your investment.

Micro cracks in the solar cells

Micro cracks are cracks in the PV cells themselves. While cracks in the glass can affect the efficiency of a panel, it’s not as serious as cracks in the cells themselves. The cracks often appear at the time of manufacturing as they’re a fault in the production, which can be due to shoddy workmanship, low quality control or faulty materials.

Any tear in the silicon cell itself will ‘interrupt’ the flow of electrons across that cell and lower the amount of electricity that the cell can produce. And unfortunately, if a cell has a micro crack in it, it’ll only get worse over the lifetime of the panel, and there’s nothing that can be done about it. That said, this should be covered under the manufacturer’s warranty.

Shading of panels

This is something you can deal with as a customer. When your solar panels are installed, the fitter should work out which parts of the array will be shaded by trees or foliage. And they should install optimisers on any panels that are experiencing shading so that they’re functioning at the same efficiency as the rest of the array.

However, if the trees keep naturally growing over your home, they may cause shading on your panels. Don’t worry, there are several ways you can combat this.

Most installations put the panels in a series, which means ‘panel 1’ is plugged into ‘panel 2’, which is plugged into ‘panel 3’ and so on. The charge must flow from panel 1 through the others, and then to the inverter. But if one of the panels in the line is shaded, it’ll bring down the efficiency of the whole line.

Therefore, fitting the panels in parallel so they all flow into the inverter without going through another panel, will reduce any losses due to shading. The only other way to combat a loss of efficiency due to shading without having to deal with the trees themselves is to fit optimisers to the affected panels.

Hot spots in solar cells & panels

This is another one that’s down to the manufacturing or fitting process. Hot spots are caused by ‘dry’ solder joints or bad connections, but mostly the bad connections as panels are tested for ‘flow’ before they leave the factory. When electricity encounters a dry joint, or a slight gap in a connection, it will ‘jump’ across the gap and cause ‘arcing’.

If it was visible, you’d see a tiny spark in the area where the fault has occurred, and those sparks will heat the area they’re in, either reducing the panel’s efficiency by making the silicon warmer or potentially starting a fire. The good news for the customer is if it’s a bad connection, it can be repaired by the installer.

It’s always a good idea to keep an eye on your inverter or monitoring system to make sure all the readings are correct and there is no loss of efficiency.

Nature damage

Birds, insects and rodents can all cause damage to your panels, with birds often being the worst of the bunch. Droppings, nests and sharp beaks can all affect the efficiency of your panels by causing shading, damaging the glass and leaving a mess all over your roof.

• Bird nets are the easiest and most cost-effective way of preventing this type of bird damage. Nets won’t stop rodents and insects though, for that you may need to investigate the roof to see what you’re dealing with or hire a professional to look for you.

• For peace of mind, insect damage is exceedingly rare. You may experience some shading if a colony of bees make a nest on your roof, but unless there is some kind of insect breakout in your area, the panels should be safe from six-legged critters.

• Also keep an eye out for squirrels as there’s been cases where they’ve nibbled wires and damaged panels.

Inverters

A solar energy system stands or falls on the inverter; it’s the piece of equipment that converts the energy from your panels to energy you can use in your home. If it’s a hybrid, it will be feeding the electricity to your battery and monitoring its charge. Inverters tend to be robust, especially as the modern one's use heatsinks to stay cool rather than fans, so they have no moving parts.

So, if your inverter is not performing as it should, it’s best to check the panels for shading and damage or make sure that the battery hasn’t reached the end of its lifecycle. If your panels and battery are in tip top condition, then you’ll need to call an expert in to investigate the problem.

Recycling

There's a common myth that goes around stating that recycling solar equipment is difficult and rare. But this isn’t true. In fact, batteries and inverters can be recycled the same way as any other type of battery or electronic equipment, usually by dropping them at your local recycling centre where specialist companies will take them away and safely use the component parts and safely dispose of the other elements.

Panels are a bit trickier, but it’s illegal to dump them or put them in landfill in the UK as they contain some hazardous waste. For this reason, solar panel recycling companies are slowly increasing in number.

Weather damage

This is probably one of the risks we need to worry about least here in the UK as we rarely experience extreme weather conditions. However, solar panels are still tested for robust weather, including hail, rain, snow, hurricanes, and high temperatures, as part of the quality control process. However, it’s important to note that the weather is unpredictable, causing damage we weren’t even prepared for.

For instance, high winds can dislodge or move panels, excessive heat can increase the resistance of cells, 5 cm of snow will block any light reaching the cells, very large hail can smash the glass on the panel, and in other unlikely cases, extreme direct lighting could burn a panel. If you experience any usual weather event, it’s worth checking on your system as soon as possible.

Lacking in appearance

This one is very subjective as it can differ with age and location. That said, the latest, modern, black-on-black panels look the part, and as a bonus, they have a higher efficiency rating. For those who aren’t as keen, thin coverings are currently being developed that would allow light to travel to the cells while ‘camouflaging’ the panels themselves.

Degradation of the cells

The solar cells themselves are subject to natural degradation due to the lifespan of silicon. For reference, each panel is subject to 0.5% loss of efficiency every 12 months. As you guessed, this solar panel performance degradation over time will not have a serious impact on the overall efficiency of the panels, especially with around 25 years guarantee.

While several problems could arise with your solar panels, it’s important to note that most of them are unlikely or easily rectified. And with a 25-year guarantee behind them, you’ll already have some peace of mind built in. If you found this blog helpful, read about solar energy myth busting.