We have to admit, we’re very excited about the rapid technological advances in Light-Emitting Diodes (LEDs). It’s possibly true that we need to get out more, but let us try to lead you down the path of enlightenment…
A while back a comedian was asked to turn on the Oxford Street lights, and joked she’d have to flick the switch at Easter so they’d light up in time for Christmas. That’s been the biggest objection to compact fluorescents, or CFLs, the most common type of energy-saving lighting - the warm-up time (or strike time). However, the famous Oxford Street display is in fact made up of LEDs, which turn on instantly, and, unlike CFLs, their performance is not affected by low air temperature.
The energy-conscious world has been telling us for years to buy CFLs, and directives by the European Union have made it obligatory to move away from the old incandescent bulbs, which waste 90-95% of the electricity they use on heat, and last on average 1,200 hours compared with 8,000 - 10,000 hours for CFLs.
LEDs, however, offer huge advantages over both incandescents and CFLs, with lifespans of 25,000 to 50,000 hours and exceptional energy efficiency of 90-95%, meaning much less than 10% of energy input is wasted on heat. But until recently LEDs have had one major drawback - the units were much more expensive to buy than other types of lighting. So although installing LEDs resulted in cost savings over their lifetime, the up-front purchasing cost tended to be off putting to organisations, due to ‘sticker shock’.
Further objections to LEDs have included the quality of the light emitted by the diodes, since the colour appeared ‘cold’ or ‘white’ compared with the warmer, more ‘yellow’ light we’ve been used to. Recent developments, however, have enormously improved both the ‘colour rendering’ and the range of ‘colour temperatures’, resulting in tones as warm as the mellowest incandescents. At the same time, rapid advances in production have significantly reduced the purchasing cost of an expanded range of LED lamps (the actual light sources - like bulbs) and luminaires (the light fixtures).
For facilities managers it’s useful to know the broad picture in order to select from modern lighting options, but for those who’d like to go into it deeper, check out the Carbon Trust’s lighting guide.
Currently, 99% of artificial light is created in one of three ways:
Light output is measured in lumens, and the Watts are the amount of electricity required to operate the light.
I’ts important to note that colour rendering is ultimately decided by the quality of the LED chips. Often most brands in wholesalers will use the lowest cost LED Chips which often have poor quality colour rendering.
CREE, SAMSUNG, and Philips (Tagra use these in most of their products) have the best colour rendering often mirroring an incandescent light output.
Comparing the energy efficiency of a product is often focussed on the ‘use’ phase of the product’s lifecycle, i.e. how efficient it is for you, the consumer, to use the product. However, the manufacture and disposal phases also involve energy demand, and all phases can involve environmental impacts such as emissions and disposal of hazardous materials. The life cycle analysis (LCA) of a product therefore considers the actual and potential environmental impacts and energy demand of a product throughout its entire life cycle.
A 2012 US Department of Energy Research Project found that both CFLs and LEDs were far superior to incandescent lamps in their environmental impacts performance and, while there was relatively little to choose between LEDs and CFLs, LEDs outperformed CFLs in all but one of the 15 categories. One of the common objections to CFLs has been the inclusion of mercury within the lamps, but in fact life cycle analysis reveals that mercury emissions to air from generating electricity from coal far outweigh emissions from use and disposal of CFL lamps (which on average contain 5mg of liquid mercury). The report includes 2017 projected results for LEDs, based on verified targets for manufacturing improvements. In the diagram, the further away from the centre the coloured line is for each lamp type, the worse the environmental impacts. LEDs are well ahead on the journey to the centre of environmental efficiency.
The life cycle analysis showed that LEDs and CFLs consume far less energy over their lifetimes when compared with incandescents, and that rapid advances in manufacturing technology means that LEDs will outstrip CFLs on the energy efficiency front over the ensuing years (see table), with vast reductions in LED packaging.
There are other aspects of lighting to bear in mind when it comes to operating efficiency - such as the fact that so much heat (90%) is put out by incandescent and Halogen lamps that this could impact on air conditioning efficacy, and such issues haven’t been included in this analysis.
However, our back-of-the-envelope calculations show that a 100W incandescent bulb burning for an hour in a small enclosed room (4m x 4m) would result in a temperature rise (all else being equal) of around 2 degrees Centigrade. Or, to put it another way, the incandescents are giving off about the same amount of heat per hour as an adult man…
When it comes to procurement decisions, we want to be able to see results in a simple format that shows what we could save. Tagra lighting took us through one of their case studies which clearly shows that industrial and commercial lighting solutions produce massive savings, and these are only going to get more pronounced as the technology continues to advance.
These are the ‘before’ and ‘after’ pictures of Tagra lighting’s client, Abbey College in Manchester. Tagra installed 25 44w LED ceiling panels to directly replace the existing CFL fittings, enormously enhancing lighting level and quality, and as can be seen by the table, saving the college 70% on energy and maintenance costs per year, and around 48% reduction in CO2 emissions.
In order to make the best choice for your organisation, the three key aspects are:
Lighting Comparisons: Incandescents, Halogens, CFLs or LEDs?
The cost comparison table includes the cost of purchase, operating and maintenance costs, and the cost of disposal.
Please note due to the cost of disposal being more complicated than other waste, we have put an ‘ad hoc cost of £5 per item. This will vary enormously with the amount you are disposing of and the contract with your maintenance company. The maintenance costs have been put in a general cost but should be taken in light of the LED lifespan.
Nowadays the affordability and flexibility of LED lighting means that any organisation retro-fitting or refurbishing would do well to invest in LED; indeed in some cases when CFL lamps burn out they can be replaced with equivalent LEDs without the need for replacing luminaires. As time goes by, the graph shows how savings of LEDs vs CFLs mount up, and with increasing energy costs worldwide, a call to a professional lighting designer is an easy win all round. For now, that is, as we haven’t even begun telling you about the organic LEDs, quantum dots, or electron-stimulated luminescence (ESLs)…
2010: Phase out of T8 halo phosphate fluorescent tubes (through minimum efficiency requirements).
2012: Phase out of T12 fluorescent (FL) tubes.
2012: Phase out of high-pressure sodium (HPS) standard quality lamps (only E27/ E40/ PGZ12 affected).
2012: Phase out of less efficient metal halide (MH) lamps (only E27/E40/PGZ12 affected).
2014: Review of the regulations by the EU Commission.
2015: Phase out of High-Pressure Mercury (HPM) lamps.
2015: Phase out of plug-in/retrofit high-pressure sodium lamps (= direct replacement for HPM). Plug-in lamps must correspond to Super/Plus HPS level; almost all plug-in/retrofit lamps will be banned.
2017: Phase out of Poor performing metal halide (MH) lamps: (only E27/E40/PGZ12 affected).
Written by Emma Littlewood
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