Glint and glare assessment: a guide to solar PV, aviation and residential impacts
At Excel Energy we provide a glint and glare assessment for solar PV developments, including agricultural solar systems, roof-mounted panels and solar car ports. In addition, we assess reflective building facades such as glazed surfaces and metal cladding.
These assessments identify potential visual hazards to light-sensitive receptors, helping clients understand safeguarding requirements and reduce the risk of objections from aviation, transport and residential stakeholders when deploying renewable technologies such as solar PV.
Table of Contents
WHAT IS GLINT AND GLARE?
Glint and glare are effects caused by sunlight reflecting from surfaces such as solar panels:
GLINT
A brief, momentary flash of bright reflected light.
GLARE
A sustained, intense reflection can cause visual discomfort, distraction, or reduced visibility.
These reflections can potentially pose safety risks or reduce visual amenity for sensitive receptors such as pilots, drivers, train operators, and nearby residents.
We use high-performance, anti-glare solar modules where appropriate to help reduce reflected light. Our options include LONGi Hi-MO X6 and Hi-MO X10 modules, which feature nano-scale anti-reflective coatings and advanced Back Contact (BC) technology. Testing indicates that total solar reflectivity can be as low as 0.9%, reducing mirror-like reflections by up to 74.5% compared with standard dual-glass modules.
We can also specify DMEGC Infinity RT Anti-Glare modules, which have been tested at the SPF Institute. Under bright-light conditions, testing recorded reflected luminance of approximately 14,200 cd/m², significantly lower than standard glass alternatives, which can exceed 100,000 cd/m².
We carefully consider every stage of our solar installation process to ensure we specify and deploy the most suitable, efficient, and technically appropriate system for each client and site. This includes considering potential glint and glare impacts, the surrounding environment, and the requirements of nearby sensitive receptors.
CASE STUDY: LONGI HI-MO X6 AND HI-MO X10 SOLAR MODULES
A great example of our approach to carefully considered solar PV design and installation is our 480 kWp commercial rooftop solar project for Euro Foods Barking in London. The project included installing 898 LONGi 535 Wp solar modules, three Ginlong Solis commercial inverters, and a Renusol rooftop mounting system.
The LONGi modules used on this project are an important part of our approach to selecting high-performance solar technology. The LONGi Hi-MO X6 and Hi-MO X10 ranges incorporate advanced Back Contact (BC) technology and anti-reflective features, designed to improve the way sunlight is captured by solar cells while reducing reflection from the module surface.
For projects where glint and glare are a consideration, the characteristics of the selected solar modules can form an important part of the wider design process. Module technology can be considered alongside factors such as panel orientation, roof layout, panel positioning, and the location of surrounding receptors to help identify and manage potential reflective impacts.
Read the full Euro Foods Barking case study to see how we delivered this 480 kWp commercial rooftop solar installation: https://excelenergy.co.uk/case-studies/euro-foods-barking-commercial-rooftop-solar-installation/
WHO CAN BE AFFECTED BY SOLAR GLINT AND GLARE?
Glint and glare assessments commonly consider potential impacts on:
Aviation Receptors
Airports, aerodromes, air traffic control facilities and helipads.
Road Users
Particularly drivers using highways and the Strategic Road Network.
Rail Infrastructure
Train drivers and other operational railway receptors.
Residential Receptors
Nearby dwellings where reflections could affect residential amenities.
WHEN IS A GLINT AND GLARE ASSESSMENT REQUIRED?
A Glint and Glare Assessment may be required where a proposed solar PV development or reflective building surface could create reflections that affect sensitive receptors.
Assessments may be appropriate for a range of developments, including:
Roof-mounted solar PV systems.
Solar car ports and canopies.
Solar developments close to airports, aerodromes, or helipads.
Solar PV developments near highways and rail infrastructure.
Buildings incorporate large areas of reflective glazing.
Buildings using reflective metal cladding.
Whether an assessment is required will depend on the specific characteristics of each site. Key factors include the location and orientation of the proposed panels or reflective surfaces, the surrounding receptors, the size and layout of the development, and its proximity to sensitive infrastructure.
We can review your proposed development and assess whether the assessment is appropriate. If we identify potential impacts, we can also consider suitable design and mitigation measures to help reduce or eliminate the risk of adverse effects.
SOLAR PV AND AVIATION: UK CAA REQUIREMENTS
The UK Civil Aviation Authority (CAA) and Combined Aerodrome Safeguarding Team (CAST) provide guidance concerning solar PV installations and the potential for glint and glare affecting pilots and air traffic control personnel.
SCOPE OF UK CAA / CAST SAFEGUARDING
Aerodrome Safeguarding:
Solar PV developments located near aerodromes may require consultation with the relevant aerodrome safeguarding authority. CAP 738 and CAST Advice Note 5 provides guidance on the potential effects of solar reflections on aviation operations.
Aviation Focus:
The assessment considers potential glint and glare affecting pilots on approach, pilots in the visual circuit, aircraft on the ground, Air Traffic Services/control towers, and relevant CNS/radar equipment.
Glint and Glare Assessment:
Where required, an aviation-perspective solar hazard assessment should be undertaken to determine whether the proposed PV installation could affect aviation operations. For larger developments, UK planning policy, including EN-3 where applicable, also requires consideration of potential effects on aviation infrastructure and aircraft flight paths.
WHAT DOES A GLINT AND GLARE ASSESSMENT INVOLVE?
A typical assessment considers factors such as:
The location and orientation of the PV panels or reflective surfaces.
Panel dimensions and proposed layout.
The position of surrounding receptors.
Sun position and potential reflection paths.
Potential impacts on aviation, highways, rail, and residential receptors.
Appropriate mitigation measures where potential impacts are identified.
FREQUENTLY ASKED QUESTIONS ABOUT GLINT AND GLARE
WHAT IS A GLINT AND GLARE ASSESSMENT?
A Glint and Glare Assessment is a technical study that evaluates whether sunlight reflected from solar PV panels or other reflective surfaces could affect nearby sensitive receptors, such as pilots, drivers, rail operators, or residents.
WHAT IS SOLAR GLARE?
Solar glare is a bright reflection of sunlight from the surface. Depending on its intensity, duration, and location, it can potentially cause visual discomfort, distraction, or safety concern.
DO I NEED A GLINT AND GLARE ASSESSMENT FOR ROOF-MOUNTED SOLAR PANELS?
Not necessarily, the requirement depends on factors such as the location of the building, panel orientation, surrounding receptors, and proximity to sensitive infrastructure. We can review your proposed installation and advise whether an assessment is appropriate.
CAN YOU MODIFY THE DESIGN TO ALLEVIATE GLARE?
Yes, where potential impacts are identified, we can consider measures such as changes to panel layout or orientation, screening, and the specification of suitable anti-reflective PV technology to reduce or eliminate potential impacts where practicable.
A CONSIDERED APPROACH TO SOLAR PV DESIGN
At Excel Energy, we take a detailed, considered approach to every solar PV installation. We assess the specific characteristics of each site and select suitable system designs, layouts, components, and mitigation measures to deliver smart energy solutions for business while considering potential impacts on surrounding receptors.
If you have any further enquiries about our solar PV systems or Glint and Glare Assessment services, please get in touch with our team through our Project Enquiry page: https://excelenergy.co.uk/project-enquiry/
One of our renewable energy experts will be happy to discuss your requirements and will get back to you as soon as possible.