As airfield operators seek to go green, more and more will look to utilise the potentially vast areas of land on or very near to their airfields for renewable energy generation. Indeed, more recently we have been receiving more inquiries from airfield operators who are looking to deploy solar photovoltaics (PV) on the land surrounding the runways and taxiways, as well as on airport structures, including hangars and terminal buildings. In this article, we present the key safeguarding considerations for an airfield safeguarding team when looking to build solar PV on an airfield to ensure the development is safely built to co-exist with aviation operations.
Physical Safeguarding – Obstacle Limitation Surfaces
For the most part, it is unlikely that solar PV panels will infringe an Obstacle Limitation Surface (OLS) due to their typically low mounting height. However when locating solar panels on a roof or in close proximity to a runway, infringements are possible. Infringements of the Approach, Take-Off Climb and Transitional surface are most likely. There is also the presence of the Obstacle-Free Zone (OFZ) in close proximity to the runway whereby there should be no obstructions that are not mounted to a frangible structure. Careful consideration should therefore be made when mounting panels near to a runway or on buildings that are already close to the limit of the OLS.
Radar and Navigation Aids
When building in close proximity to a navigation aid, the potential for impact as an obstruction or through electromagnetic (EM) interference should be considered. As an initial assessment, it is worth considering the safeguarding zones defined within the relevant civil aviation authority publications (CAP 168 in the UK) or ICAO DOC 015 (Building Restricted Areas). Based on Pager Power’s experience, as long as the solar development is built to the appropriate electrical specifications, EM effects are unlikely.
Engine Failure After Take-off (EFATO)
An EFATO may result in an aircraft having to conduct a forced landing in an area around the airfield, often off the end of a runway and not within the airfield’s land ownership. Under an EFATO, it is recommended that a pilot does not conduct turn greater than 45 degrees of straight ahead to ensure airspeed and height are maintained as much as possible. There is no defined safeguarding area for an EFATO. It may therefore be beneficial to consider how ground-mounted solar developments are laid out in areas off the end of a runway.
Air Traffic Control Tower
The Air Traffic Control Tower is the most important point for visual surveillance across an aerodrome for looking at both operations in the ground as well as in the air. It is therefore of paramount importance that the development of solar PV does not hinder the view from the ATC Tower’s visual control room. This may be from the physical blocking of key viewpoints or via glare from the solar panels themselves. A glint and glare assessment is a key assessment requirement for any on or near airfield solar PV development, in fact for any development capable of producing specular solar reflections.
Figure 1: Air Traffic Control Tower. 
Approaching, Departing, Taxiing and Circuiting Aircraft
As per the details presented on the ATC Tower in the section above, glare towards pilots in aircraft is also a key consideration. The key receptors are pilots on approach and circuiting the airfield however in a small number of instances, glare towards departing and taxiing aircraft has been a consideration (although not a key safeguarding concern. The effect of glare may have implications upon the layout of the PV panels.
Wildlife and Birds
Whilst not specifically within Pager Power’s area of expertise, the possibility of the solar panels attracting nesting birds or other wildlife should be a consideration when developing a solar development on or near to an airfield.
There are a number of safeguarding considerations when developing solar on an airfield. The list presented above notes the key issues Pager Power has encountered when working with airfields to maximise PV potential. It is likely that the layout and location of a PV development will be influenced and balanced against the safeguarding of the airfield.
About Pager Power
 Thunderbirds at Melbourne Airshow (March, 2018) from Unsplash.com. Last accessed on 17th September 2021. Available at https://unsplash.com/photos/40s5X5D9Aqo