Having signed into law the next tranche of targets, which commit the country to reducing its carbon emissions by 57% relative to 1990 levels by 2030, the UK Government is stepping up its emphasis on sustainable policies designed to promote clean generation and greater efficiency. As well as a focus on renewable sources of power, these policies also include measures to improve the energy performance of the UK’s buildings, both current and yet to be built.
It’s a sensible plan, because buildings make up a large percentage of the UK’s carbon footprint – accounting for nearly 40% of the nation’s greenhouse gas emissions and nearly 70% of electricity consumption, much of which is produced by carbon-heavy generation methods like gas, coal and oil power. The low-hanging fruit in this mission would seem to be its own buildings, and there are quite a lot of them: In 2011 the Government calculated there were over 180,000 buildings in public ownership meeting a variety of needs, from sports stadia to hospitals.
Though there is plenty of work for central Government to do on this, two thirds of the total property portfolio is actually managed by the 86 local councils around the UK, so these areas have been the focus of much of the work. Initiatives such as the Green Investment Bank have been rolled out to incentivise the take-up of energy efficient technology, and help regional bodies become greener.
|2012 Olympic venue The Copper Box, managed by the Greater London Authority,|
makes extensive use of LEDs and light tubes
Lighting is an extremely important arena when it comes to sustainability in buildings because it is so ubiquitous and so costly as a result. It is also all around us wherever we go, in our homes, offices and streets, so it must be comfortable and practical for us to live with. Energy spent on lighting buildings represents 19% of UK energy use, which equates to tens of millions of pounds and 32 million tonnes of Carbon Dioxide. LED lighting is widely accepted by the UK Government and Governments and climate organisations across the world as the most promising avenue for the future of lighting, and investment in the technology across the world is expected to grow to $160bn by 2020.
|LEDs can produce a variety of colours, making them more|
versatile to use in design
For local councils, these are game-changing benefits in energy efficiency. The potential cost savings are obvious, as is their utility in meeting carbon-saving objectives, but they also make sense as part of the wider economic eco-system. Even the most advanced fluorescent lamps can’t match the lifespan of an LED, meaning they have to be replaced far less frequently, and their durability means that failure rates are low and they suffer less from decay in light output as they age. They also come in a variety of colours enabling them to more effectively mimic natural daylight in office environments, and as streetlights can reduce light pollution by being much more directional – only providing light where it is needed.
All this being the case, there is a danger of complacency. LED technology is a growing and exciting area of the lighting industry, but it’s far from a ‘magic bullet’ solution. Like any technology, it has to be implemented properly, and with consideration for its impact on the whole system. No energy efficient solution is ‘fit and forget’, and the worst thing a council could do would be to assume that switching to LED is an automatic win.
Firstly, judging the performance of an LED is not as simple as looking at the values of the chip. It might have Ferrari performance on paper, but a lot depends on the effectiveness of the system it is designed into. It can only perform well in a luminaire (light fixture) that suits its strengths, making sure it is at the right temperature for example, and trying to get one to perform in a badly designed context will greatly reduce its performance and may even damage it over time – like taking your Ferrari on quicksand. There are many different light sources and set-ups that best suit specific circumstances, so it’s vital an engineer designs the system to get the best out of the LED solution.
|LEDs are extremely versatile, but require correct installation to deliver|
the expected results
This is a great advantage when implemented with other systems like motion sensors to turn the lights off when there’s nobody around, or to dim them when it’s brighter outside. LEDs should not just be used as a direct replacement for older light sources – the irony is that LEDs can be so much cheaper that we then use too many of them, wiping out cost and carbon savings. Without controls more sophisticated than a light switch, that’s not an efficient solution, and a properly designed control system can do a lot to alleviate these issues.
The old adage ‘you get what you pay for’ also applies here. Lighting is more complex than simply ‘on’ and ‘off’, with factors such as the light colour temperature and the colour rendering –and it’s not a purely artistic consideration, it also has the potential to impact on the wellbeing and productivity of the people who live and work in council buildings. Cheaper, poorer quality LED lights can perform less effectively in a number of ways, but one of the most notable is in light rendering – this is the way in which the light from the source accurately represents the colour of objects in a room. Cheaper and poorer quality LEDs are less effective at this, and so the light in a room may appear ‘off’, which can have negative psychological effects for the occupants.
|LED light can be sympathetic to the Circadian Rhythm, which|
can be disrupted by artificial light
LED technology is the biggest advancement in lighting in recent times. Its efficacy is improving at a high rate, while at the same time costs are falling. It will be an integral part of the energy efficiency strategies of a wide variety of people, companies and governments for years to come, but it is important to remember that it can’t be taken on its own as a complete solution to the problem of efficiency in lighting.
In order to ensure that the technology is properly utilised so that it is as effective and efficient as possible, local councils will have to ensure that it is professionally designed as part of a wider strategy that bakes efficiency into the design of their buildings. It’s not as simple as replacing one technology with another like-for-like: it needs to be properly installed by an engineer following industry guidance, such as that produced by the Society of Light and Lighting and the Chartered Institution of Building Services Engineers, to be as effective as it can be, and ensure that works harmoniously with the building, the occupants and the other systems in play.