PV system causes glare – do I need to be concerned?

Glare effects in a PV system occur when the partially extremely bright reflections cause visual discomfort. In some cases, such impairments can even become hazardous, for example, because road users are distracted by the reflected sunlight or their vision is temporarily impaired. In a shaded environment, they may not see properly for a short time if they are dazzled by the PV system. Glare from solar modules can also be unpleasant for neighbors.
In the past, solar modules usually faced south to convert as much sunlight as possible into electricity. In these cases, the light is mostly reflected upwards, so glare rarely occurs. However, nowadays, solar systems with other orientations are increasingly being installed, leading to a significant increase in glare problems. Below you will find a brief list of the main risk factors for glare caused by solar modules: 

• Photovoltaic systems oriented east, west, or north tend to reflect light downward, causing glare, for example, on the terrace of the neighboring property.  

• On a slope, for example on a south or west-facing slope, reflections can radiate into neighboring houses at higher elevations. 

• The duration and extent of glare from solar modules decrease with greater distance. If houses are close together, however, the glare problem increases both in time and space. The viewing angle also plays a role.  

• There are significant seasonal effects due to the changing position of the sun. A system that was glare-free in midsummer can already become a nuisance in autumn. Depending on the latitude, there are typical “glare seasons.” In Germany, these are between March and May and from August to October; in Spain, for example, winter is particularly affected. 

• The presence times of the neighbors also play a major role. Fully employed neighbors are often away from home during typical glare times and tend to complain less. 

• Last but not least, the neighborly relationship is important – if a conflict already exists, a lawyer is often involved very quickly. In a friendly relationship, however, there is often a willingness to find a solution together and possibly even share the costs. 

High quality of living in a good neighborhood

Interest in PV systems is rising in many residential areas, making glare from solar modules an increasingly relevant issue. In the interest of good neighborly relations, it is therefore important to consider before installing the PV-System considering the above-mentioned risk factors. 
If the neighborhood relationship is already somewhat tense, you should place particular emphasis on avoiding glare caused by Photovoltaics to avoid and, if in doubt, a Glare report obtain. This concerns not only the optimal installation location and angle but also the characteristics of the modules. 

Misunderstanding "Anti-Reflection Coating"

Typically, today's PV modules equipped with an "Anti-Reflection Coating" (ARC). Unfortunately, this layer only serves to increase yield and offers no protection against glare effects. This fact is unknown to many solar installers or is concealed due to lack of alternatives. Once the modules are on the roof, the damage is usually done, and the solutions then proposed, such as a hedge to pto use plants or blinds are of little help. A dismantling of the PV-Installation following an expensive and nerve-wracking legal dispute is the typical course. 

Forward-looking measures 

To avoid this inconvenience, it makes sense to use glare-free modules from the outset if there is a potential glare risk. In addition to frosted modules, such as those offered by companies like 3S or Megasol, Phytonics provides an innovative product that can "de-glare" any solar module: The XRF Anti-glare film, with its special microstructured surface, ensures that especially shallow incident light is better coupled in and the reflected rays are completely diffusely scattered. As a result, there are no direct reflections of the sun that could cause glare. The reflected brightness remains well below the often-cited glare threshold of 100,000 cd/m² even at very shallow light incidence of 70° to the surface normal, with 75,000 cd/m². Caution is advised, however, with so-called "Anti-Glare" modules based on deeply textured glass. These cannot sufficiently suppress reflections of shallow incident light but sometimes distribute them in a way that actually increases the glare problem.  

The Anti-glare film from Phytonics allows you to orient the solar modules as desired without the risk of glare. Measurements show that the film significantly outperforms other glare-reducing surfaces. At the same time, the high performance values are maintained, so the annual energy yield remains almost unchanged.
The XRF Anti-glare film consists of a durable, weather-resistant, and UV-resistant adhesive film and a scratch-resistant special layer with a structured surface. These two components have been used worldwide outdoors for many years, and accelerated aging tests in climate chambers have demonstrated the excellent durability of the film. 

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