Efficient LED lights are appearing more and more in homes, businesses and industry. Today, LEDs (Light Emitting Diodes) use about 85% less electricity than a conventional lighting source such as an incandescent bulb. They may soon use even less.
This is a significant reduction. Around 19% of the world’s electricity demand is used for lighting; compared to just 3% goes to smelting aluminium – although in Australia we only use about 12% of our electricity for lighting and 8% for smelting aluminium.
A simple (but not perfect) measure for lighting efficiency is the number of lumens (a measure of light intensity) a lighting source produces per watt.
A conventional incandescent bulb gets 13 lumens per watt to light your room, while a replacement LED bulb from Philips that can be bought at Coles or Woolworths achieves 80 lumens per watt (a compact fluorescent globe gets about 60 lumens per watt – see technical note at the end)
So, where is LED lighting going?
CREE (the industry leader who, it is speculated, may purchase the next best, Philips’ Lumileds division) has successfully demonstrated Light Emitting Diodes running at 300 Lumens per watt in the lab. CREE currently sell a $10, 9.5W bulb (available in the US), which produces 85 Lumens per watt and can directly replace an old style 60W globe.
Other breakthroughs and innovations are contributing to achieving higher efficiency’s in LED lighting, including a breakthrough by German researchers http://www.ciol.com/ciol/news/217344/german-researchers-cut-energy-loss-half which will not only effect LED lights, but laptop and mobile phone chargers, cutting losses in today’s most efficient power supplies by half from 10% to just 5%.
Taking all this into consideration, according to the US Department of Energy SSL (Solid State Lighting) program http://energy.gov/eere/ssl/solid-state-lighting we should be able to achieve wall plug efficiencies of 250 Lumens per watt by 2020 which means that a conventional bulb replacement in 2020 would be available using only a third of the electricity of today’s LED bulbs.
3 Watts to light a room
At that staggering rate of 250 lumens per watt, it will only take 3W to light a room, when it used to be done with 60 Watts of power. This represents a 95% reduction in energy required for lighting.
This will have a profound effect on the world’s requirement for lighting energy. We can expect – on an absolute basis – that 19% of the world’s electricity which is currently used for lighting to dramatically drop by at least 75%. On today’s numbers the reduction is the equivalent of the entire electricity consumption of the European Union.
In developed nations these huge efficiency gains from LEDs in the lighting sector will contribute to the continuing restructure of the electricity supply industry, which is currently facing a death spiral unless it can electrify the remaining residential energy services coming from fossil gas and supply a fast tracked electrification of the world’s vehicle fleet.
In developing countries, rooms that can be lit with 3W and task lights with even lower electricity consumption. This means that almost all the remaining 1.5Billion of the world’s population without an electricity supply will be able to access one at very minimal marginal cost in the next 5 years.
While energy requirements and costs for lighting go down, photovoltaic and battery efficiency’s are going up and their costs are coming down as well. This nexus means that turnkey solar photovoltaic panels, with batteries and high performance lighting will be the mobile phone of the all-electric renewable revolution. leapfrogging the old fixed line poles and wires alternative creating ubiquitous world-wide electricity provision.
LED’s will be the starting point and other services such as mobile phone charging, laptops, basic machines (sewing) and cooking will flow from there.
In order to focus capital and research and development efforts towards achieving the lowest cost and highest efficiency lighting, wealthy countries such as Australia should be specifically focussing research and development efforts.
This can be done through institutional and non-institutional research grants (equivalent to the US DoE and EU programs) and agencies such as the Clean Energy Finance Corporation. To be effective it must make inroads into financing wholesale changeovers of the nation’s lighting infrastructure ato use the most efficient technology as an incentive for suppliers to retool, upscale and mass produce the newest and highest performance LEDs.
In addition, halogen and fluorescent lighting should be phased out the same way incandescent lighting has been phased out to create even greater incentive to researchers and developers and manufacturers.
The future is looking bright for LEDs and the applications are unlimited, LED’s have had a strong impact on the auto sector, street lighting, appliance back lighting, bicycle lighting and are now even being used for greenhouses saving significant energy when growing food in controlled environments.
(Technical note: These are wall-plug efficiencies meaning the efficiency measurement is taken at the 240 Volt electrical socket, in the case of the LEDs if the measurement is taken at the correct DC voltage of the semiconductor then the lumens per watt rating is quite a bit higher. However wall-plug efficiencies are the most useful measure for consumers to compare with existing lighting and they are commonly quoted).