The Importance of Socially & Environmentally Sustainable Lighting Design in Tackling Light Pollution – by Kerem Asfuroglu

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This blog is written by Kerem Asfuroglu from Dark Source who will be speaking at our 2025 Ireland Conference on Nature Restoration on 10 April. Book your ticket to hear Kerem’s presentation.

Plas Y Brenin – Before & After images by Karl Midlane & Dylan Parry Evans

At no point in our history have we produced and consumed light more than we do now, bringing an increase in light pollution at an alarming rate, with impacts on our health and the environment, especially nocturnal biodiversity. It has also reshaped our perception of not only the night sky, but also the night.

However, protecting dark skies is a labour of love which relies heavily on collaboration, and the number of people focusing on this topic has never been greater. Thanks to the growing pool of committed people and communities, we have never been better equipped to tackle light pollution. Unlike the other pollutants, it is relatively easy to eliminate light pollution and its adverse effects: switch it off and the problem is gone.

That is easier said than done, because light pollution is not just an environmental problem, it is also a cultural problem. Even the terms we use for communicating light – such as ‘brightness’ and ‘darkness’ – can be very subjective from both cultural and individual perspectives. Mechanically, it may be easy to switch something off but culturally, doing so is challenging.

The challenge is greater today because we live in the age of light, when the majority of the surfaces we interact with emit it and it is widely accepted that illumination is excessively consumed as a visual embellishment, celebration and communication tool. Lighting is treated as a silver bullet to all societal issues; however, there is still no strong evidence which proves that more light deters crime after dark.

For these reasons, Dark Source seeks to develop practical precedents for the judicious and considerate use of light and make them work with the help of committed, inventive communities striving to restore and protect their dark skies. In the quest to install illumination that respects the night, it is crucial to make the process of design development inclusive, so that everyone involved takes part throughout the project, not merely after it has been finalised.

There are clear causes of light pollution & simple ways to eliminate it:

  1. Use light only when necessary: Illumination that is not meant for any particular reason or purpose is excluded.
  2. Choose warm colour temperatures: ≤ 2,200 Kelvins should be used as warm colour temperature is least harmful for both the wildlife & the night sky.
  3. Minimise glare and brightness: Our vision is harmed when intense light glares. The design uses lighting sensitively & judiciously to ensure it’s comfortable on the eye.
  4. Angle it downwards: The scheme avoids over lighting and clutter by directing light downwards and using the correct beam distribution.
  5. Apply lower mounting height where possible: Lower mounting height contains light spill more effectively.
  6. Use switch off, dimming or PIR sensors: By employing remote control, dimming and PIR technology, lights are only on when needed in order to reduce carbon emissions and electricity bills.
  7. Keep nature dark:  A healthy natural world needs natural darkness to function. Avoid the illumination of wildlife; including trees, water bodies and potential nesting areas

Here are ttwo case studies which illustrate how dark sky spaces can be beneficially designed with and for the people who live in them.

Newport, Mayo, Ireland

Images by Georgia MacMillan & Michael McLaughlin

Ireland is a nation with great potential to establish several dark sky areas, and these possibilities have been adopted at Newport, a town with ambitious aspirations to become the first dark sky community in Ireland.

The scheme also sought to create an aesthetically enhanced illuminated night-time environment, thus ensuring social and visual sustainability as well as environmental value. As part of this project, two local architectural landmarks, St. Patrick’s Church and the Seven Arches Bridge, were identified as sites where lighting redesign could eliminate the light pollution and visual discomfort currently caused by their poor illumination.

The first phase of the project focused upon replacing the glaring floodlight scheme at St. Patrick’s Church, which was lit by luminaires that diminished the beautiful heritage architecture of the 100-year-old building. Visible from numerous points in the town, its hilltop location intensified the adverse effects of the poor lighting, with large quantities of wasted glare ascending into the sky and failing to bring out the ornamental features of the church’s facade. The project sought not only to change the lights one by one, but also to futureproof the design and thus avoid perpetuating environmental problems in the future.

Before, vertical façade lighting had shaped the visual emphasis when seeing the church at night, and this was inverted by instead putting the emphasis on the horizontal ground plane. Next, lanterns were reinstalled on the perimeter railings, which has restored the heritage fabric of the church both by day and at night. These lanterns are designed to provide a warm colour temperature (2200K) and subtly illuminate the church periphery without causing any glare. This has encouraged the public to visit and explore the church grounds after dark, overcoming the dazzling floodlights which formerly inhibited movement.  In addition, a switch off time was established for the lighting, allowing a period of rest for both the environment and the architecture.

The first phase of the project has already reduced the annual CO2 emissions by two tonnes and cut down the light pollution rate by 50%. From successfully applying for grant streams to organising dark sky festivals and carrying out lighting tests on site, the community of Newport has a tremendous capacity to initiate change which led the project to success.

Presteigne & Norton Dark Sky Community, Powys, Wales

Images by Leigh Harling Bowen

Covering an outer area of 40km and a combined population of 2,700, the historic Radnorshire towns of Presteigne and Norton are located in Powys, the largest county in Wales and which shares a border with England. In contrast to other areas of the UK, more than 20% of Wales has been assigned dark sky status. Precedents like this are important as they pave the road for bigger and more populated settlements to challenge the norms in order to become dark sky friendly.

In developing environmentally friendly lighting for the residents of the town, a judicious lighting approach has been essential. In Presteigne & Norton’s case, the street lighting was the main layer of illumination causing problems. Orange tinted sodium lighting had been replaced with cool white LEDs (a colour temperature of 6500K), which saved Powys County Council a significant amount of money by reducing running costs. However, the blue-rich colour of this LED light introduced more significant light pollution problems, flooding the streets with radiance.

Frequent sky quality monitoring and engagement programmes organised by the local community raised awareness, which eventually ensured the protection of a large area that is home to light-sensitive bat species and the nearby Spaceguard Centre observatory. A total of 380 lighting columns were refurbished with warm white LED luminaires (lighting units, with a colour temperature of 2200K); about half of them were programmed to switch off and the rest to dim by 50% after midnight.

Spectral readings showing the improvement rate before & after the street lighting refurbishment. Courtesy of Brian Healy.

Comprehen­sive lighting tests were carried out and feedback was sought from the wider community throughout the project, which has reduced the town’s annual CO2 emissions by 4.5 tonnes. Its success has prompted the county council to consider rolling similar lighting schemes out across the county. This will empower many other communities to pursue dark skies accreditation if they so choose, an important ripple effect for the continuity of dark skies across Wales and the UK.

This achievement is a product of a unique collaboration between the local community, Presteigne & Norton Town Council, Powys County Council and the lighting designer.

This blog was written by Kerem Asfuroglu who will be speaking at our 2025 Ireland Conference on Nature Restoration on 10 April. Book your ticket to hear Kerem’s presentation.

By Kerem Asfuroglu is the founder and director of Dark Source – an award-winning environmental lighting design studio based in Ireland & UK.

References

Dark Sky Ireland. (2024) DSI Environmentally Friendly Lighting Guide. https://www.darksky.ie/wp-content/uploads/2024/05/DSI-Environmentally-Friendly-Lighting-Guide-4.pdf

Friends of the Lake District. (2023) Good lighting technical advisory note: Designing out light pollution in Cumbria and Arnside & Silverdale AONB. https://issuu.com/friendsofthelakedistrictpublic/docs/cumbria_-_good_lighting_tan?fr=sYzU0MjY3Njg2NjY