A typical case – glare caused by a PV system
We receive daily inquiries from PV system owners, neighbors, and installers who have been caught off guard by a glare problem. Each case has its peculiarities, but there are many commonalities and recurring stories, misunderstandings, and disputes that we want to illustrate for you here using the fictional case of a Mr. Müller as an example:
The Müllers live in a single-family home in a quiet residential area. To contribute to combating climate change and due to recently high energy costs, they want to implement their very own energy transition: they are acquiring an electric car, replacing the gas heating with a heat pump, and naturally want as much electricity as possible to come from their own roof. Therefore, the Müllers aim to install as many solar modules as reasonably possible. In addition to the southeast roof, the northwest roof is also to be fully equipped with modules. After all, solar modules have become very affordable, and excess electricity can be stored in the 30 kWh home battery.
It is May; finally, the solar technician has come and installed the modules – from now on, the Müllers are pleased to have affordable, climate-friendly electricity in abundance and are proud to set a good example in the neighborhood.
The scaffolding has been removed, and the first proper sunny day in a long time arrives – the PV system on the roof is producing an impressive amount of electricity, the electric car and battery storage are fully charged by evening, which Mr. Müller monitors on his smartphone thanks to the smart integration of all components.
The next morning, there is a knock at the door; it is the neighbor, Mr. Schumann. Mr. Müller opens the door beaming with joy, as he assumes Mr. Schumann wants to congratulate him on the PV system and is interested in the details.
Instead, Mr. Schumann gets straight to the point without greeting: "The solar panels on your roof – they must be taken down immediately! Yesterday, we were constantly dazzled for over two hours, making it impossible for us to stay on the terrace!"
Mr. Müller is perplexed and has his neighbor show him the problem – indeed, the glare effects are immense, there is no room for discussion. The solar installer is also (or at least pretends to be) surprised. He insists that this has never happened to him before, moreover, he installed modules with low-reflection coatings and refers to the module datasheet, which states that the front glass is anti-reflective coated.
After the initial shock has been overcome, all three affected parties begin to consider possible solutions. It is considered whether the neighbor could simply install an awning, or whether planting a hedge could block the view of the roof and thus prevent the glaring reflections. Alternatively, raising the modules on mounts to change the emission angles so that the light no longer reaches the neighbor is discussed. A seasonal covering of the modules with a tarp is also considered.
Upon closer examination, however, all proposed solutions prove impractical. Since Mr. Müller is also unwilling to dismantle his modules, the positions harden and the neighbor issues an ultimatum: a solution must be found by the next glare season in spring, otherwise he will involve his lawyer.
The next spring arrives, and the glare returns. Subsequently, Mr. Müller receives a letter from the neighbor's lawyer stating that legal action will now be taken. A first court hearing follows, and an expert is appointed who confirms that an unreasonable glare is present. The court then orders the dismantling of the system.
The seriousness of the situation prompts Mr. Müller to intensively research further solutions and he eventually discovers the possibility of reducing glare by applying a special film to the modules. He receives a sample from the film supplier, which he then shows to his neighbor. They agree to give it a try and initially laminate a single module. Since Mr. Müller's solar installer is also glad to get through the matter with minimal damage, he agrees to carry out the lamination work. For this, the module must be dismantled, thoroughly cleaned, and then reinstalled on the roof.
On the next sunny day, the result can be evaluated: while the surrounding modules cause significant glare, the laminated module is completely glare-free and is not perceived as disturbing.
At the next hearing with the judge, the parties agree that all modules will be laminated and the neighbor will withdraw his lawsuit. The costs for the lamination will be shared between the solar installer and Mr. Müller – however, the court, attorney, and expert fees have now risen significantly to €12,000 and initially remain with Mr. Müller.
Please contact us for further information or questions: info@phytonics.tech