Battle of the bulbs

Cutting domestic bills with energy-efficient lighting

By Peter Feuilherade

More affordable prices and an increasing range of energy-saving light bulbs are driving consumer take-up of energy-efficient lighting for the home, particularly in Western Europe, North America and some Asian markets.

Models of CFL bulbs (US Department of Energy) Models of CFL bulbs (US Department of Energy)

Incandescent bulbs fading away...

For generations, domestic lighting has been dominated by incandescent bulbs, which radiate light from a heated tungsten filament. They waste about 95  %of the electricity they consume, by creating heat instead of light, and last an average of 750 to 1 000 hours. As they are withdrawn from sale over the next few years across the world, consumers are switching to more efficient alternatives that are not only cheaper in the long run, despite initial start-up costs, but are also environmentally friendly.

The future is bright, the future is energy efficient

Energy-saving lamps for the home can last many more times longer than traditional bulbs, cutting down on domestic electricity bills. They come in three main varieties: CFLs (Compact Fluorescent Lamps), LED (Light-Emitting Diode) based lamps and halogen lamps.

CFLs are what most people visualise when they think of energy-efficient light bulbs. They are miniature versions of full-sized fluorescent lights that screw into standard lamp sockets and give off light that looks similar to that of incandescent bulbs. CFLs are widely available and offer a cost-effective option for general lighting purposes.

Halogen bulbs are not as efficient as CFLs and do not last as long, but still use between 25 and 40 % less energy than traditional light bulbs.

LEDs are small solid light bulbs which are extremely efficient. New LED bulbs are grouped in clusters and have diffuser lenses that broaden their applications for domestic use. Rapid advances in technology are making the price of LED bulbs more affordable, and manufacturers are introducing a growing range of styles. Although initially more expensive than CFLs, LEDs offer more value over the life of the bulb since they are more energy efficient, last longer and deliver the best cost savings in comparison with other types of bulb.

Compact and bright

In comparison with incandescent bulbs, CFLs use up to 80 % less electricity when turning energy into light, and they last up to 10 times longer. Each CFL is expected to reduce CO2 (carbon dioxide) emissions by about 590 kg over its lifetime. They are available in all shapes and sizes. Different colours are available, ranging from warm yellowish traditional lighting to a cooler pure white for enhanced visibility.

Modern CFLs do not flicker and can reach full light output fairly quickly, although not instantly in the way other technologies do. CFLs can be applied nearly anywhere that incandescent lights are used.

Standard CFLs can last for up to 3 000-6 000 on/off switches. They should not be used when lights need to be switched on and off frequently, as this will reduce the lifetime of the bulb. A special type of CFL able to last up to 1 million switches is available for such applications. Dimmable CFLs are also available for lights that require a dimmer switch

LED into the future

LED-based lighting, which evolved in the 1960s, is growing as the most promising alternative to CFLs. LEDs are 90 % more efficient than incandescent bulbs and use the light emission properties of particular semiconductor materials. Although initially designed for commercial use, because they were expensive to produce, improved technology and economies of scale have seen prices fall, making them increasingly attractive to domestic consumers.

Manufacturers have expanded the application of LEDs to home lighting by using clustered bulbs containing up to 180 small LEDs encased in diffuser lenses which spread the light in wider beams. Units are now being produced with standard bases that fit common household light fixtures. They can of course produce spot lighting as well as general light. LED lighting technology lasts up to 10 times longer than CFLs and up to 25 times longer than halogens.

Although LED bulbs cost more to buy, their low energy use and long lifetime mean that when used for two to three years or more, they offer a more cost-effective solution than halogen bulbs. Over periods of nine years or longer, their running costs work out cheaper than those of CFLs.

LED bulbs offer a long life. Typically the lifespan is 40 000 hours compared with the average lifetime of 6 000-15 000 hours for a CFL bulb or 3 000 for a halogen bulb. Their main benefit, however, is in the tiny amount of energy they consume: a 4,5 W LED can be used to replace a 50 W halogen. It will offer the same light output while reducing CO2 emissions and running costs by 90 %.

Other advantages of LED bulbs include: no heat is emitted into the environment, so domestic air conditioning costs are reduced; resistance to shock; unaffected by multiple switching; no maintenance required; colour stability; directional, eliminating light pollution; environmental benefits from energy reduction in manufacture, packaging, distribution, storage and end of life recycling, owing to the smaller number of products needed.

LEDs have been described as "the only fundamentally new lamp technology to enjoy commercial success in the last 100 years". The implications for the lighting industry are far-reaching. In the words of the UK’s (United Kingdom) ESKTN (Environmental Sustainability Knowledge Transfer Network), "the semiconductor Light Emitting Diode (LED), and its organic cousin the OLED, are emerging as a completely disruptive light source technology in the lighting industry. The shift is characterised by a step-change from gas and glass based technologies to solid-state and is forecast to be as disruptive to the lighting industry as the change from valves to transistors was to the electronics industry".

Phasing out old-style bulbs

The production and sale of old-style incandescent bulbs is being phased out over a number of years in many countries including Australia, Brazil, Canada, China, Thailand, the US (United States) and the EU (European Union). Cuba was the first country to start, back in 2005.

In the EU, which began phasing out old-style bulbs in September 2009, lighting accounts for 14 % of all electricity used – 430 TWh per year. Of that, 20 % is used by private households.

In the US, energy-efficiency federal legislation that comes into effect in 2012 sets out a timetable for phasing out incandescent bulbs. The Energy Independence and Security Act of 2007 imposes a requirement for roughly 25 % greater efficiency for light bulbs, phased in from 2012 until 2014.

China is to ban imports and sales of 100 W and higher incandescent bulbs from October 2012, while bulbs of 60 W and above will be banned from October 2014. Lighting accounts for 12 % of China's total electricity use. The country's National Development and Reform Commission estimates that the switch will save 48 billion kWh of power per year and reduce CO2 emissions by 48 million tonnes annually.

Future growth

In 2007, the International Energy Agency estimated that lighting accounted for just under 20 % of electricity use worldwide and about 28 % of total energy consumed for domestic purposes. In November 2011, Transparency Market Research predicted that LEDs would be the fastest growing sector of the overall lighting market, enjoying a CAGR (compound annual growth rate) of 14,9 % from 2011 to 2016. While the US is expected to be the biggest LED market in 2016, the Asian region will witness the highest growth, with a CAGR of 16,6 % from 2011 to 2016.

In Asia, demand for LED products is growing among customers in developed countries such as Korea and Japan. This is mainly driven by the high cost of energy, so the high initial purchase price is offset more rapidly. A number of regional and national government programmes to promote LED lighting will serve as key drivers of the Asian market in the coming decade. According to a  November 2011 report from Pike Research, sales of LED lighting systems will increase rapidly in Asia Pacific over the next 10 years, accelerating sharply after 2015. Unit shipments, including lamps and luminaires (light fittings), are forecast to rise from 66 million in 2011 to 542 million in 2021 – an increase of more than 700  %.

In India, the total market for LED lighting is expected to grow to USD 400 million by 2015 (53 % per annum), making it one of the fastest-growing sectors. India's Ministry of Power estimates that potential savings from changing light bulbs to new LED technology could reduce electricity demand by as much as 40 %.

This expansion can be observed in other parts of the world. According to data released at the second annual SIL (Strategies in Light) Europe 2011 conference published in LEDs Magazine, the LED lighting market in Europe is expected to grow at a CAGR of 41 % between 2010 and 2015, with the fastest growth in the replacement-lamps sector as legislation to remove inefficient lamps from the market takes effect.

The global LED lighting market had revenues in excess of of USD 5 billion in 2010, of which 21 % was from replacement lamps and the remainder from luminaires.

IEC showing the light

The IEC TC (Technical Committee) 34: Lamps and related equipment, and its SCs (Subcommittees), have been working on LED standards for several years. Lawrence Barling of The Lighting Association in the UK, chairman of IEC SC 34A: Lamps, said: "As always the initial focus has been on safety standards but also several PAS (publicly available specifications) have now been issued covering the performance and measurement of lamps, luminaires and LED modules. The use of a PAS in this area has allowed industry agreed specifications to be quickly developed, which has helped unify the way performance claims are being made by manufacturers and testing is conducted."

Standardization was widely discussed at SIL Europe 2011, in particular quality criteria for LED luminaire performance based on IEC/PAS 62717, LED modules for general lighting – Performance requirements, released in April 2011, and the two parts of IEC/PAS 62722, Luminaire performance, released in June 2011. Both PAS cover LED luminaires for general lighting.

The LED lamp market is full of companies that would be classed as non-traditional lighting companies. Barling said: "Many of these are from Japan, Korea etc., but also many EU-based SMEs (Small and Medium Enterprises) are taking advantage of this new, high tech and rapidly increasing market. For these companies, having good industry standards is critical as many have never previously been involved in lighting".

Educating consumers

Many consumers are still not fully aware of the benefits of LED technology. Incandescent lamps have been used for over 100 years and are all that most people know, making it difficult for them to change their purchasing habits. As with any new technology, cost is one of the main reasons for the slow uptake. Consumers need to be advised about the energy saving potential and longer life they will get with LED bulbs, and persuaded that LED technology is worth the initial investment cost.

Potential adopters have also been put off by the unappealing appearance of many energy-saving bulbs and lights for the home. Some CFL "designer" products are gradually arriving on the market.

Energy-efficient bulbs, having been introduced in commercial, office and industrial settings for some time, are a mature technology in these marketplaces. They are now expanding rapidly into the residential market as their unit prices drop sharply and as governments introduce incentives to encourage their take-up and measures to phase out their incandescent counterparts. Households, with the promise of lower energy bills, and the lighting industry, with a new growing market, are set to benefit from this expansion in the long term.

Models of CFL bulbs (US Department of Energy) Models of CFL bulbs (US Department of Energy)
LED-based lamps are now finding their way into homes (Photo: OSRAM) LED-based lamps are now finding their way into homes (Photo: OSRAM)
Plumen designer CFL bulb (Photo: Plumen) Plumen designer CFL bulb (Photo: Plumen)