(The author is a Reuters market analyst. The views expressed are his own.)
The LED lighting industry is set to dominate the global market more than a century after its discovery, benefitting from a widespread ban of conventional incandescent bulbs and as the market share of competing green replacements fade.
Light emitting diodes (LEDs) have a vital edge in that they have superior energy efficiency and longer lifespans compared with rivals, while a global glut in LED chips means they are becoming more competitive.
A forecast explosion in LED sales by more than 40 per cent annually will see the technology eclipse high-efficiency rivals such as compact fluorescent lamps (CFLs).
Meanwhile, the main LED market challenge of high upfront costs is eroding.
And, while concerns remain of a potential manufacturing bubble stemming from a boom-bust cycle of over-capacity - which has been seen in other clean energy technologies sectors such as wind and solar - freedom from subsidy programmes may see demand rise more smoothly than with fickle government support.
LEDs will surge in the U.S. lighting market, to a 36 per cent share in 2020 and 74 per cent in 2030, a U.S. Department of Energy report forecast last year, implying $30 billion in annual energy savings by 2030.
The study, "Energy Savings Potential of Solid-State Lighting in General Illumination Applications", forecast rapid gains after 2014 as prices continue to fall.
McKinsey is even more aggressive for the global 55 billion euro ($68 billion) general lighting market (which excludes automotive and specialist backlighting), forecasting a 45 per cent LED market share in 2016 from 9 per cent in 2011.
LEDs would usurp traditional efficient light bulbs such as CFLs, the consultants said in their "Perspectives on the global lighting market" study in August.
Developed countries are banning incandescent light bulbs on the basis that they are inefficient and contribute to global warming and energy insecurity, while governments chase building efficiency programmes.
The International Energy Agency reported that 26 of its 28 member countries had policies in place to phase out incandescent bulbs as of 2011, except in New Zealand and Turkey.
The European Union (19 EU countries are IEA members) last year phased out all non-directional, clear incandescent light bulbs usually used in household illumination.
The United States banned 100-watt incandescent light bulbs from October last year, followed by 75-watt bulbs this month and with 60-watt bulbs to follow.
Among emerging economies, China said it would ban 100-watt incandescents from October last year, with other varieties following through 2016.
Incandescent light bulbs produce light when an electric current runs through a wire inside the bulb's glass globe, causing the wire to heat up and glow. Halogen lamps are similar but add a gas which extends the product lifespan and allows them to operate at higher temperatures.
LEDs generate light when electricity flows through an electronic component called a diode.
CFLs and fluorescent tubes emit light when electricity excites a mix of gases inside the bulb, creating invisible ultraviolet light that is absorbed by the bulb's fluorescent coating and transformed into visible light.
LEDs are an old technology but will now become the dominant technology in the wake of the incandescent ban.
Britain's H.J. Round is credited with being the first person to publish the light emitting diode effect, in 1907.
Modern LEDs are superior to CFLs in terms of total environmental impact including the energy and natural resources needed to manufacture, transport, operate and dispose of light bulbs, concluded a report published in September by the U.S. Department of Energy's Pacific Northwest National Laboratory (PNNL) and UK-based N14 Energy Limited.
It compared the most typical and widely available light bulb in each technology class: LEDs, CFLs and incandescents.
With regards to operating efficiency, LEDs and CFLs were neck and neck: the bulbs each created about the same amount of light (800-900 lumens) but the incandescent bulb consumed 60 watts of electricity, followed by the CFL's 15 watts and LED's 12.5 watts.
But LEDs beat CFLs on overall environmental performance, including the energy and resources needed to make them.
LEDs cost more but have a longer life span: the PNNL report assumed its standard LED bulbs to last 25,000 hours for 2012 models, compared with 8,500 for CFLs and 1,000 for incandescents.
McKinsey forecasts a less than two-year payback by 2016 in the residential market and around three years in offices, from around 10 years now.
Environmental buyers are already converted, such as investors Climate Change Capital whose Tim Mockett reported on Wednesday a rapid 18-24-month payback on a recent LED lighting retrofit, replacing conventional fluorescent strip lighting.
A bigger test of demand will be adoption in large-scale public procurement programmes including street lighting projects which are gathering steam.