Rooftop solar panels can be an attractive option for commercial building and households alike. It can be an efficient use of committed space, it’s environmentally friendly and under the right circumstances it can save a lot of money.
Naturally, there are hurdles to overcome, one of which is solar glint and glare. This is common issue for ground-mounted developments, but it should not be ignored for rooftop schemes.
Figure 1: Glare from a rooftop development. (© Pager Power 2016)
There have been cases of rooftop panels being removed following glint and glare complaints – read more about a UK example of this here.
What needs to be assessed for rooftop solar schemes?
The receptors that need to be assessed are:
- Dwellings that could have a view of the panels.
- Road users that could have a view of the panels.
- Airports that could be affected by the development.
- Railway lines adjacent to the property with the panels.
With regard to aviation, an assessment would typically be required for developments within approximately 5 km of an airport. In some cases, assessments are requested at greater distances, particularly if a development lies beneath a final approach path.
Difference between rooftop schemes and large-scale solar
Pager Power’s overall assessment approach for rooftop schemes is the same as for larger, ground-mounted systems. This is because the reflection effects and potential impacts are the same in both cases.
Figure 2: Rooftop solar development.
The difference is that the number of potentially affected receptors and the overall duration of any impacts tend to be less for rooftop schemes than for larger systems. This is because the panel area is smaller, and because the visibility of the panels is often restricted to a smaller number of observers.
A robust assessment must be based on:
- Full consideration of potentially affected receptors.
- Detailed modelling of potential effects for observers that have a view of the panels.
The modelling should accurately map the reflection time and duration, based on the path of the Sun throughout the year.
In practice, adverse effects are often more restricted for rooftop schemes than larger developments. However, this does not remove the requirement for a glint and glare assessment.
Pager Power Can Help
If you need a solar glint and glare assessment for your project (located anywhere in the world), please call +44 (0) 1787 319001 to speak to a member of the technical team and request a proposal. Alternatively, you can also email firstname.lastname@example.org and someone will get back to you.
Pager Power has completed over 300 glint and glare studies so far. These have been for developments including, but not exclusive to, rooftop solar schemes, ground mounted solar arrays and building developments.
Image accreditation: “rooftop view of the solar array” by h080 via Flickr / CC BY-SA 2.0 / Image resized from original.