Every day we receive enquiries from PV system owners, neighbours and installers who have been caught off guard by a glare problem. Every case has its own particularities, but there are many similarities and recurring stories, errors and disputes, which we would like to illustrate for you here using the fictitious case of a Mr Müller as an example:

The Müllers live in a detached house in a quiet residential neighbourhood. In order to help combat climate change, but also because of the recent high energy costs, the Müllers want to implement their own personal energy revolution: They are buying an electric car, replacing the gas heating with a heat pump and, of course, they want as much electricity as possible to come from their own roof. The Müllers are therefore trying to install as many solar panels as possible. In addition to the south-east roof, the north-west roof is also to be fully equipped with modules. After all, solar modules have become very cheap and surplus electricity can be temporarily stored in the 30 kWh house battery.

It’s May, the solar installer has finally arrived and installed the modules – from now on, the Müllers are delighted – they have an abundance of cheap, climate-friendly electricity and are proud to be setting a good example in the neighbourhood.

The scaffolding is dismantled again and the first real sunny day in a long time arrives – the PV system on the roof produces a fantastic amount of electricity, the electric car and battery storage system are fully charged in the evening, which Mr Müller tracks on his smartphone thanks to the smart integration of all components.

The next morning, the doorbell rings – it’s his neighbour Mr Schumann. Mr Müller opens the door beaming with joy, as Mr Schumann would certainly like to congratulate him on the PV system and is interested in the details.
Instead, Mr Schumann gets straight to the point without saying hello: ‘The solar panels on your roof – they have to come down again immediately! Yesterday we were permanently dazzled for two hours, we can no longer stay on the terrace!’

Mr Müller is perplexed and asks his neighbour to show him the problem – the glare is indeed immense, there’s nothing to discuss. The solar installer is (or at least acts) just as surprised. He insists that this has never happened to him before and that he has installed extra low-reflection modules and refers to the module data sheet, which states that the front glass has an anti-reflective coating.

After the initial shock has been digested, all three parties concerned start to think about a solution. They consider whether the neighbour could simply install an awning, or whether a hedge could be planted to block the view of the roof and thus the dazzling reflections. Or whether the angle of radiation can be changed by raising the modules so that the light no longer reaches the neighbour. Seasonal covering of the modules with a tarpaulin is also being discussed.
On closer inspection, however, all solutions prove to be impractical. As Mr Müller is also unwilling to dismantle his modules, the fronts harden and the neighbour issues an ultimatum: a solution must be found by the next glare season in spring, otherwise he will call in his lawyer.

The next spring arrives and the glare is back. Mr Müller then receives a letter from his neighbour’s lawyer stating that legal action will now be taken. The first court hearing follows, and an expert is appointed who confirms that the glare is unreasonable. The court then orders the system to be dismantled.

The seriousness of the situation prompted Mr Müller to research further solutions and he finally came across the possibility of removing the glare from the modules by applying a special film. He receives a sample from the supplier of the film, which he then shows to his neighbour. They agree to give it a try and initially film a single module. As Mr Müller’s solar installer is also happy to get out of the matter with a black eye, he agrees to carry out the wrapping work. To do this, the module has to be dismantled, then thoroughly cleaned and put back on the roof.

On the next sunny day, the result can be assessed: while the surrounding modules are extremely dazzling, the foiled module is absolutely glare-free and is not perceived as disturbing.

At the next meeting with the judge, the parties agree that all the modules will be wrapped and the neighbour will drop his complaint. The costs for the foiling will be shared between the solar installer and Mr Müller – however, the court, legal and expert costs are now significantly higher at €12,000 and will initially remain with Mr Müller.

Please contact us for further information or questions: info@phytonics.tech