Vehicle drivers depend on good visibility. Glint and glaring has the potential to impede the visual perception, which can cause traffic disturbances and accidents. Drivers and pilots of cars, trucks, trains and airplanes could overlook obstacles, other vehicles, light signals or traffic signs (disabiltiy glare or physiological glare). The solar irradiation with an unusual intensity and from an unusual direction can also disturb neighbors of the installation (discomfort glare or psychological glare).
Reflective Glint and Glare
Why a Solar Glare Assessment?
Large reflecting areas such as glass or metal facades or PV-plants can direct sunlight to places where people at work are blinded on a large-scale and thus experience discomfort glare. Since changes on these installations after construction are usually costly, the execution of a glaring survey is recommended when in doubt.
The glint and glare study helps to assess the dangers resulting from the planned installation. The calculation allows the quantification of reflection parameters (when, how often, from which direction and how long glaring should be expected). It assists mitigation of dangers and setting unreasonable fear from glaring into perspective.
Savings with a Glint and Glare Study
A solar glare analysis helps to avoid solar panel glare and thus save construction costs by getting it right the from the beginning. Based on a submission plan the survey can predetermine glaring and thus suggest cost-efficient solutions already in the planning phase. But also existing plants with a glaring hazard can be improved reliably and cost-efficiently with a solar glare calculation. This is why a glint and glare study for large scale PV-plants located close to traffic routes or inhabited areas is often mandatory.
Support with building permits
While earlier the standards and guidelines for glaring from artificial light where employed (e.g. BS 5489, CIE 150, DIN EN 12665) just recently the respective guidelines especially made for the glare from solar plants have been published. In Germany the Light-Guideline (Licht-Leitlinie) issued by the Ministry of Environment defines limits for reflective solar glare, especially with respect to solar power plants. In Austria regulation OVE R11‑3 (from the Austrian electrical engineering association) provides rules and methods for the analysis of the glaring from PV power plants. A professional assessment helps to quantify the physical facts, collect all relevant influences from the environment, gives recommendations and thus helps to reduce potential uncertainties. Our Glare Assessments are compliant with both of these directives and we do provide all necessary parameters like point of time, duration and line of vision angles. Consequently, we are able to analyse the issue of the dazzling effect clearly and concisely, thus supporting rapid and definite decisions in the building permitting process.
The quantification of the dazzling effect is essential for the estimation of the immission dose (strength and duration). Especially the duration of immission and the direction of the glare are essential factors to allow an assessment of its risk potential. Zehndorfer Engineering is leading in the area of reflective glare calculation and is able to calculate glaring reliably and in detail based on building plans.
Read more on glare calculation on the next page...
How we can help you
Disability glare study in Langenlebarn / Austria
The survey showed a reasonably low glare by the planned photovoltaic roof installation. This helped to remove concerns of the ministry of devense regarding the operation on the adjacent military airport.
Dazzling of the railroad traffic in Seesen / Germany
At the existing PV-plant the disability glare disguised the light signal of the adjacent Deutsche Bahn railroad. A glaring survey was executed, which helped to find and implement the most cost-efficient and effective glare-reducing provisions.
Dazzling effect on highways and state roads
The dazzling effect on truck and car drivers was quantified by the calculation of glare duration, travel time and viewing angle. Consequently concerns could be cleared in many cases. In the remaining cases the angle of PV panels were adjusted to reduce the duration of the dazzling effect and thus create reasonable visibility conditions for motorists.