14 minute read
DARK MATTERS
driver was the return on investment made possible by replacing legacy luminaires with ultra-efficient LED versions. As with any business case, the lower the capital cost, the quicker the return on investment, and this, coupled with offshoring of manufacturing, created the low-cost LED luminaire. In many schemes the visual quality of the space and the visual comfort provided to occupants were very secondary considerations.
Therefore it does not require much imagination to suggest that industry and governmental calls to deliver net zero carbon buildings will lead to a renewed focus on any building service that is a consumer of energy. By doing so, with consumption correlating to emissions, we minimise the need for carbon offsetting or as yet largely unproven carbon capture and storage. Will lighting quality again be under further pressure? So as not to be constrained by a blinkered, energy-only approach, we need to understand and communicate all the aspects that make up better (lighting) in a net zero carbon building.
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In discussing the theme of the latest SLL LightBytes, I suggested that we should update the Right Light, Right Place, Right Time mantra for a net zero carbon age and that this might usefully become Minimum Energy, Minimum Resource, Maximum Comfort. We, of course, have an unavoidable duty to minimise our in-use carbon emissions for the sake of the generations to follow us, hence Minimum Energy. Maximum Comfort covers a wide range of requirements from visual comfort to wellbeing and the creation of fit-for-purpose stimulating spaces.
This article focuses on Minimum Resource – the other half of the emissions in use equation, being the embodied resources used to build the luminaire and whether that resource use through life is in itself sustainable.
The old joke about how many (fill in your stereotype) does it take to change a light bulb doesn’t work any more. The LED and the driver are often integral to the fitting so if one were to fail you have to replace the whole thing – you simply can’t repair it, life extend it, even if you wanted to. LEDs are more energy efficient and they are part of our green jobs revolution that drives economic growth – all that is true, but it is not the whole story. The huge (pre-Covid) growth of LED lighting had already brought its own problems.
As an example, let’s think about the hospitality sector, increasingly the focus of ever more wonderful lighting designs. While each individual luminaire is likely to be fairly energy efficient, there are now many more of those fittings, and in a fastmoving sector new fit-outs are common. Now many would not unreasonably think that we recycled all those replaced conventionally lamped fittings, or those fittings ripped out prior to a hospitality or retail refit, but I present you with an inconvenient truth: 'In 2019, 42,000 tonnes of lighting equipment were placed on the UK market,' according to Nigel Harvey, chief executive of Recolight. 'Only 2700 were recovered through WEEE schemes. The amount officially recorded as reused was zero'
So what happened to all these luminaires, not forgetting that the WEEE
directive came into force in 2003 so any equipment 18 years old or younger all proudly bore the crossed-out wheelie bin mark? The harsh reality was that much was sent to landfill. What did go to a grandly named Approved Authorised Waste Treatment Centre saw any value in your old luminaire literally shredded to recover the metals, which themselves would need energy inputs to melt them down for reuse. Green? No.
We have to make better use of the resources embodied in our lighting equipment. An unthinking linear economy of Take (resources from the environment), Make (products in factories), Waste (dispose of products into the natural environment) is no longer acceptable. Part of the problem here is that we measure economic growth in terms of sales revenue, but we don’t measure our environmental impact.
Before you start thinking that I’m a bit of a Luddite, stuck in a pre-LED world where everything looked better through (2700K tungsten) tinted spectacles, then I should point out that our industry is not alone. We would all applaud the rapid uptake of PV
p The hospitality sector is increasingly the focus of attractive lighting but while individual luminaires
are probably energy efficient, there are now many more of them and new fit-outs are common
'The only person who thinks we can have infinite growth in a finite world is either a madman or an economist' – David Attenborough
solar generation, but it has been estimated that we could be facing 80m tonnes of endof-life PV modules by 2050, that could form more than 10 per cent of global e-waste.
The high energy efficiency of LED luminaires does not solve the problem of lighting sustainability without ensuring that the technology itself is sustainable. Adopting the circular economy is the accepted process of maximising resource usage, keeping (in our case) lighting assets at their highest value, in other words as an effective luminaire for as long as possible. I will not dwell too long on the topic of what the circular economy is, others before me have already done so. However, the other day I found myself penning an article entitled ‘How many Presidents does it take to change a Light Bulb? Why? Well as David Attenborough will be the first to remind us, the environment will not wait. We need practical action right now. This will most likely take the form of legislation, supplier innovation, specifier or clientled demand, dissemination of practical knowledge and the adoption of assessment methods. So what could this president of the SLL do?
A team of us got together and we started listening, consulting, learning, engaging, and what is soon to come out of that process is a suite of three tools. The objective is to give information to all, enable supply push by creating a nuts and bolts tool for manufacturers, and to stimulate demand pull by giving specifiers and clients the questions they need to ask.
The first tool in the suite is the forthcoming CIBSE SLL Technical Memorandum on The Adoption of the Circular Economy in the Lighting Industry. It describes the background to the circular economy in general, including the drivers behind its adoption, but most importantly it provides guidance on how the circular economy affects each sector of the industry, what opportunities it may bring them and what to do next.
We are also near the completion of the SLL’s Circular Economy Assessment Method for Manufacturing (CEAM-Make) which allows manufacturers (or specifiers, if they so wish) to assess the performance of their luminaire and its supporting ecosystem in terms of its circular economy performance. The products are rated a score out of four. The objective is to move as many products and manufacturers from zero to hero (four) as quickly as possible by giving them the detailed issues to consider. The assessment method is comprehensive, covering product design, manufacturing, materials and supporting ecosystem.
The CEAM-Make may be a little too indepth for a busy specifier to use every time they need to choose between luminaires, or in the transition period where manufacturers have not yet fully completed their CEAM-Make assessments. Therefore, the third part of the suite of tools is the SLL's CEAM-Design, being a specifier support tool. You could almost think of it as a triage tool, being essentially the most important questions to ask a manufacturer.
All the tools in the suite have been created in full consultation with people knowledgeable in the field, from manufacturers to product designers, lighting designers and end users. The tools will be updated, but the hope is that they will deliver the practical know-how, understanding and level playing field for claims that make an already green industry in terms of its product’s in-use energy performance, truly sustainable.
While I hope that our suite of tools (and we have already thought of at least another two to add to them) delivers real and measurable change, I must sound one note of advice for future
p Lighting is not uniquely complex:
the product as a service concept already covers jet engines to copiers, while the toner cartridge itself is a poster child for remanufacture
SLL presidents: don’t write brand new Technical Memorandums or software tools in combination with your busy year as president. If you do it is highly unlikely that either your bank manager or your family will still be talking to you at the end of it. It is perhaps best summed up by Peter Fordham of Sainsburys: 'Bob, you were either brave or you didn’t think it through.'
Having said that, in my presidential address I also said that I couldn’t do it alone. Much of the SLL’s and CIBSE’s work is only made possible by its volunteers. Many, many people have played their part in this work, too many to list them all but special thanks must go to Kristina Allison, Andrew Bissell, Sophie Parry, Anastasia Mylona, Simon Fisher, Roger Sexton, Mark Ridler, Tim Bowes and Tom Ruddell.
Bob Bohannon, MSc, FSLL, MIET, is a lighting designer, sustainability expert and educator, and, until May, president of the SLL. He is also currently leading the team writing the SLL's Circular Economy Fact File and Assessment method
The three tools, newly developed by the SLL to promote the circular economy in lighting, are scheduled to be available by early summer: • CIBSE SLL Technical Memorandum on The Adoption of the Circular Economy in the Lighting Industry • Circular Economy Assessment Method for Manufacturing (CEAM-Make) • CEAM-Design: specifier support tool
DARK MATTERS
p Nocturnal view of the UK seen from space
For the first time the SLL is expanding its advice on illumination and the night-time environment into a full lighting guide. Benedict Cadbury summarises why such guidance is now indispensable
Liz Peck was writing this excellent light schemes, so this guide could almost guide, LG21: Guide to Protecting have formed a checklist for the project: the Night-time Environment, in skyglow, obtrusive light, bat flyways, fish, the months before her untimely visitor views, extending the economic day death in January 2021, bringing it very near of Ironbridge, curfews, luminance-based to completion. It was a subject that she was design, spectral reflectance and light source passionate about, in her work protecting spectral radiation, daytime appearance, glare bats from the negative effects of light, in her mitigation through positioning, aiming and architectural lighting design, and also in her louvres, and finally an overall lighting impact wide-ranging work for the SLL. assessment – all were included.
Bob Bohannon had the privilege to It is easy to identify examples of dreadful work alongside Liz on the award-winning exterior lighting where the benefit to the scheme for the Iron Bridge at Telford, and owner of the illumination is more than on reading this guide it was good to see just cancelled out by the negative side-effects how much of the knowledge and advice set of light spill on neighbouring properties out within it were incorporated into the and those who live and work in them. The lighting design of the bridge. Liz had long had rot started with 500W halogen floodlights Durdle Door in Dorset, lit by Michael Grubb Studio for NoHLexpertise in mitigating the negative effects with over-sensitive PIR control and then of lighting on bats and Bob had extensive continued with wide-angle LED floodlights experience in delivering zero direct upward at 5000K. It culminates in glaringly bright E
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moving LED displays, and garish Christmas illuminations at first floor level flashing on and off all night.
This is an area where guidance is indispensable. The SLL Guide to Limiting Obtrusive Light, written by Peter Boyce, was first published in 2012. Nine years on it is time to expand this into a full lighting guide, with additional material relating to LED light sources, and consideration of how light can affect human and animal circadian systems. Legislation lumbers up slowly in the rear: the Clean Neighbourhoods and Environment Act (2005) includes light on the list of statutory nuisances, which means that property owners (and the lighting designers who may work for them) are legally obliged to consider the effect of any exterior lighting on neighbours.
Electric light is capable of being harmful not only to humans, but animal and plant species. For humans, glare and flicker are obvious problems. First, flicker does not have to be visible to have an effect; secondly, many LED lights which operate satisfactorily on full power produce increasing flicker as the driver dims the light source, hence if lights are planned to be dimmed in use, for example with daylight-linking, the flicker factor/flicker index needs to be ascertained at 50 per cent and 25 per cent as well as 100 per cent output. Although sky glow might not at first be thought of as bad for health, if it means that city centre dwellers sleep less well because of the lack of complete darkness outside, this clearly has an implication for their wellbeing.
PROTECTED SPECIES
More than half the world’s species are nocturnal, thus exterior illumination in or near their habitats can cause problems, particularly if it is in operation throughout the hours of darkness. Bats are at the top of the list, but nocturnal birds such as owls suffer; many small mammals, such as mice and shrews, rely on darkness to avoid predators. A significant number of animals and birds are protected in the UK; the Appendix lists 101 vertebrates in this category, including the dormouse, hedgehog, otter, red squirrel, shrew, barn owl and many songbirds, not forgetting crested newts and natterjack toads. Disturbance of any of these species is illegal, therefore lighting designers need to consider carefully the effect of an exterior lighting scheme not just on neighbouring properties but also on native wildlife. This is especially pertinent on the edge of a built-up area or a greenfield site in the countryside.
BLUE LIGHT
Blue light is of particular interest when considering circadian entrainment and the negative effects of electric light on wildlife. In the past street lights were generally monochromatic sodium; now LED street lights, generally 4000K–5000K, contain a good deal of blue light. A 4000K LED source typically has a blue-light content of around 33 per cent, whereas a warmer 2700K light source has only 16 per cent. As a general rule, blue-rich white light disturbs nocturnal creatures more than warmer, narrow-waveband sources, so it is essential to consider the spectral distribution of a light source in assessing its impact on the natural environment.
SHOULD IT BE LIT?
The first question has to be whether or not the lighting is necessary or justifiable. Much of it is indeed necessary, for example for safety of movement, security, or work such as loading vehicles. The next category is desirable, for instance to extend the economic 'day' of a town centre, lengthen the time that leisure facilities can be used, or illuminate landmarks. At this point the lighting designer and client need to make a realistic assessment of the negative effects to weigh against the benefits.
LESS IS MORE
There is a tendency to think that more or brighter lighting is better. If a private client or hotel asks for a garden to be lit, it is far more effective to light a few well-chosen focal points rather than flood the whole space with uniform illuminance. Of course, safety considerations mean that steps and the edges of any water features need accent lighting, but this can be local and discreet.
LIMIT THE HOURS
There is no reason to exclude external lighting altogether because of harmful side-effects on wildlife or human neighbours. Clients frequently want features lit on winter evenings, which might mean 4-9pm. Having conducted a lighting impact assessment it might well be decided that, with a curfew at 9pm, the entire scheme would be acceptable, whereas if it was to run to midnight, then a restriction on the number of luminaires and/or their lumen output would have to be imposed.
The guide offers practical advice and useful suggestions, whether for sports pitches, heritage buildings or car parks, drawn from the author’s extensive experience. Good practice examples are given and there is a checklist of considerations before a lighting scheme is submitted for planning permission.
Humans are naturally a diurnal species, but we have the tools to turn night into day anywhere on a crowded planet shared with other humans, flora and fauna. The power to use these lighting tools should be used wisely, with care and consideration. Not every building needs lighting, not every surface needs to be lit, and we should be cognisant of the impact of any light that escapes our projects.
Lighting Guide 21: Guide to Protecting the Night-time Environment, substantially written by Liz Peck and finalised by Benedict Cadbury, is scheduled for publication this summer. The All-Party Parliamentary Group of MPs for Dark Skies was formed in 2019. Its first policy paper, urging the government to adopt 10 policies to help resolve light pollution, was launched on 9 December 2020. It can be viewed and downloaded at https://appgdarkskies.co.uk/policy-plan
