Getting the Green Light
Hidden between the colourful, glass walls of the Microstructural Analysis Unit (MAU) at UTS sits a man whose half-dozen or so fish watch him work. Professor Matthew Phillips insists that the current in the fish tank flows in such a way that by swimming facing the glass "it’s the fish-equivalent of putting your feet up".
But perhaps the fish just want to know what he’s doing with all those lights.
Until their phase-out in February 2009, incandescent bulbs (globes with a wire filament) had been the light bulb of choice for homes around the world for 100 years.
While effective producers of light, incandescent bulbs are not efficient; almost 95 per cent of the energy put into them is lost in heat. And with 20 per cent of the world’s electricity consumed in lighting, that’s a lot of wasted energy.
This is where Professor Matthew Phillips, Director of the MAU, and his Green Lighting Research (GLR) team come in.
“Green lighting is energy-efficient lighting,” he explains.
Phillips and the GLR team are working to improve light emitting diode (LED) technology so these lights can be used in homes.
The current replacement energy-efficient domestic light source is the compact fluorescent light (CFL). While CFLs are a vast improvement on incandescent lighting, they have some drawbacks: CFLs contain mercury which, when the light bulb is broken, is released into the atmosphere.
“CFLs contain about 4mg of mercury – that’s enough to pollute 100,000 litres of water,” says Phillips.
Already, LEDs are used in traffic lights, car break lights, and as a replacement for domestic halogen down-lights. All these lights, however, have a spot focus and are therefore unable to light an entire room. Domestic bulb replacement LED lights are available now, but they are also very expensive – starting at $60.
Phillips and his team are working to improve the quality of material in LEDs so the bulbs emit more light and the price decreases.
“We’re trying to understand the formation of defects in the material, which reduce the amount of light that the semiconductor produces. So we’re trying to understand how these defects form, how to minimise them and establish their role in the light emission process.”
LEDs are about five times more efficient than incandescent bulbs and last for almost 100,000 hours – almost 10 times longer than CFL bulbs.
“This basically means that you have a domestic light source that, under normal circumstances, would last forever. So the real question is, do you still need light sockets when you build a house?”
Greater energy efficiency means the introduction of domestic LED lighting will significantly reduce our reliance on coal power, and carbon emissions.
It is predicted that LED technology will reduce the world’s greenhouse gas emissions by 10 gigatonnes of carbon (about 10 per cent of global CO2 emissions) over the next decade. The decrease in Australia alone is greater than 28 million tonnes of carbon – equivalent to taking 500,000 cars off the road.
“In principle you could eliminate 10 per cent of the world’s electricity consumption by using LED lights," says Phillips. "And that has a dramatic impact on the economy. Energy rates are going up. In fact it is predicted that by 2050 global electricity consumption is going to double.”
Phillips is also enthusiastic about the potential of combining LED technology with renewable energy resources, such as solar and wind power, to make it a totally self-sufficient lighting source.
“In the future, it is entirely conceivable that all electric lighting will be taken off the electricity grid. This means that we can bring lighting to developing communities that don’t have access to electricity.”
Perhaps the most exciting part about Green Lighting Research is that “this technology is in its infancy". Who knows what will be lighting our homes in 10 years.
Words: Anna Watanabe