Simon Shenton from lighting supplier Luceco describes how LED technology has permanently disrupted what was a stagnant market offering prescribed solutions for each sector, to provide the dominant solution for the future.
The global lighting market has seen more innovation in the last 10 years than the previous 100. It is unrecognisable in 2016 compared with the turn of the millennium, when I joined the lighting industry. Product ranges were a lot smaller, and different technology approaches divided the sector.
Low level commercial lighting was dominated by fluorescent technology, Cat 2 silver grill louvre was the only way to limit the glare on your computer screens, and retail lighting was CDM-T lamps. In the domestic sector, innovation never got past halogen and high level lighting for industrial applications or street lighting was High Intensity Discharge lamps in Son or Metal Halide.
Back then, product development was relatively slow; moving from T8 lamps to T5 was a big development but other than that innovation was few and far between.
A new leader
Although LEDs have been used as indicator lighting in a wide range of applications since the 1950s, it wasn’t until the process of making ‘white light’ was discovered in the 1990s that LED could offer a potential general lighting solution. It then wasn’t until circa 2005 when LEDs became efficient enough to consider using for general lighting.
Now LED dominates the commercial, retail, domestic and industrial sectors, and sales have seen a rapid rise in the last five years, so much so that by 2020 it is predicted that 90 per cent of all lighting sold will be LED. The technology has now settled down following its initial period of expansion, and consumer confidence is growing as prices fall.
There are several compelling reasons to choose LED. Product efficiency far exceeds any other technology. LEDs also offer instant light, which can be dimmed with a suitable driver, but also white, high quality light with low heat, no mercury and 50,000 hour lifetimes.
Manufacturers are also offering five year warranties as standard.
Market evolution
The rapid growth of LED technology has also forced changes on the market, for the better. With LED’s weakness being its internal heat output, lighting manufacturers have been forced to advance their knowledge in the area of thermal management. Product development now includes thermal simulations to ensure the LED junction temperature is kept at the right level.
Luminaire designers are now finally designing products to use LED technology to its best potential, rather than just retrofitting the technology into housings of historical fixtures. LED fixtures now use lenses to guide the directional light source, and diffusers to soften the glare. The overall footprint of luminaires is becoming smaller and thinner.
Light output ratio can now almost be removed from specifiers’ list of lighting concerns. Historically typical 5 ft twin luminaires all had the same lumen output because they designed around the lamp’s lumen rating; the light output ratio determined the amount of light emitted from the luminaire. With LED you cannot measure the source on its own accurately as it requires the luminaire body for thermal management. Absolute photometry is used where the lumens output of the luminaire is measured, removing the requirement for the Light Output Ratio.
With increased lifetime and guarantees, the market is now seeing the introduction of on-site warranties as manufacturers put their name to their long-lasting products. Luminaires are typically now being quoted to clients based on their lumen output rather than their wattage, which is a big change for the end user who for years has purchased that 40, 60 or 100 Watt bulb.
Changing the parameters
A further change driven by LED innovation is that lifetime is no longer the period up to to when the lamp fails – average life is now based on when half of the LED chips reach 70 per cent of their initial lumen output (L70). The product development time is more akin to computer technology with months between iterations of products rather than years.
Even some guides and standards are now being revised or questioned with LED, including LG7 maximum glare above 65 degrees having been doubled from 1500 to 3000 cd. In addition future iterations of Building Regulations and enhanced capital allowance criteria means that only LED products will comply.
CIE’s colour rendering index system provides a single number (known as ra) to reflect a light source’s ability to render colour. However, this has recently been brought in question when used with LED. A second method known as TM-30 that provides two numbers for a light source is being reviewed as it is more suitable for use with LED.
LED has certainly changed the lighting industry forever, but the jury is out on whether the technology will succeed in reducing power consumption or whether the energy savings will be cancelled out by all the new areas using LED for decorative lighting that would have had lighting installed previously. Partly to address this, increased integration of smart technology controls will further drive future innovation in the sector.
Simon Shenton MSLL is product manager at Luceco Lighting