A Typical Case – Glare from a PV System
We receive daily inquiries from PV system owners, neighbors, and installers who have been caught off guard by a glare problem. Every 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 Mr. Müller as an example:
The Müllers live in a single-family home in a quiet residential area. To contribute to fighting climate change, but also because of the recently high energy costs, they want to make their very own energy transition: 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. Therefore, the Müllers try to install as many solar modules as reasonably possible. Besides the southeast roof, the northwest roof will also 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’s May, the solar installer has finally come and installed the modules – from now on, the Müllers are happy to have cheap, climate-friendly electricity in abundance and are proud to set a good example in the neighborhood.
The scaffolding has been taken down, and the first real sunny day in a long time arrives – the PV system on the roof is producing a fantastic amount of electricity, the electric car and battery storage are fully charged by evening, which Mr. Müller follows on his smartphone thanks to the smart integration of all components.
The next morning there’s a knock at the door; it’s the neighbor, Mr. Schumann. Mr. Müller opens the door beaming with joy, as he’s sure 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 have to come down immediately! Yesterday we were constantly blinded for over two hours, staying on the terrace is no longer possible for us!”
Mr. Müller is perplexed and has his neighbor show him the problem – indeed, the glare effects are immense, there’s no question about it. The solar installer is also (or at least pretends to be) just as surprised. He insists that this has never happened to him before, plus he specifically installed low-reflection modules and refers to the module datasheet, which states that the front glass is anti-reflective coated.
After the initial shock has been digested, all three affected parties begin to think about a solution. They consider whether the neighbor could simply use an awning, or whether planting a hedge could block the view of the roof and thus prevent the glaring reflections. Or whether raising the modules on supports could change the emission angles so that the light no longer reaches the neighbor. A seasonal covering of the modules with a tarp is also discussed.
On closer inspection, however, all proposed solutions prove impractical. But 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. Mr. Müller then 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 commissioned who confirms that there is an unreasonable glare. The court then orders the dismantling of the system.
The seriousness of the situation prompts Mr. Müller to intensively research further solutions and he finally comes across the possibility of reducing glare by applying a special film to the modules. He receives a sample from the film provider, 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 out of the situation with minimal damage, he agrees to carry out the lamination work. For this, the module must be dismantled, thoroughly cleaned, and then put back on the roof.
On the next sunny day, the result can be evaluated: while the surrounding modules glare enormously, the laminated module is completely glare-free and is not perceived as disturbing.
At the next appointment with the judge, the parties agree that all modules will be laminated and the neighbor will drop his lawsuit. The costs for the lamination will be shared between the solar installer and Mr. Müller – however, the court, lawyer, 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