Home insulation, much maligned for its association with the scrapped government stimulus program, has helped propel a startling reduction in household energy use.
After 50 years of steady rises, the amount of energy used by Australian households has fallen to its lowest point in more than a decade.
“I think [home insulation] definitely has lowered power consumption,” says Alan Pears, a lecturer in home design and environmental sustainability at RMIT University. “Insulation is essentially the first thing you do when you're trying to improve a house's energy rating.”
The amount of energy houses use began falling in about 2005 and dropped 5 per cent over the next three years, according to the 2011 State of the Environment report, the government's environmental audit conducted every five years. Since then, electricity use has fallen even further.
“We've observed falls of 2 per cent a year over the last four years,” says Paul Myers, a sustainability expert at the energy company Ausgrid. “It's a very interesting and significant reversal.”
The government's audit found increasing use of home insulation was a primary cause of the drop. The proportion of insulated homes rose between 2002 and 2008 from 57 to 61 per cent.
A further 1 million homes – about half the overall target – were insulated between 2009 and 2010 under the government's home insulation scheme before it was scrapped because of concerns about safety and fraud.
Pears says it is difficult to measure precisely the effect of insulation because there is so little data on household energy consumption.
More energy-efficient appliances, stronger national regulation of home design, higher electricity prices and people switching from electric hot water to more environmentally friendly kinds have all contributed to the reduction in electricity use. But he argues the government's scheme has had a significant impact.
“If you look at the western suburbs of Sydney, you've got a lot of very large houses built in the 1990s with black roofs, many of them completely uninsulated. If those houses run airconditioning, which many have to, then putting insulation in could make a very big difference to their overall power use,” Pears says.
The $2.4 billion scheme, part of the stimulus policy during the global financial crisis, became a highly politicised issue when the government was attacked for implementing the scheme too hastily.
Four electricians died after installing insulation unsafely and against program guidelines, and insulation provided under the scheme was linked to 90 other house fires. A number of electricians who claimed subsidies under the scheme were thought to have been unqualified or to have obtained money fraudulently. Investigations into these cases are continuing.
Pears agrees the stimulus program was flawed but is dismayed that the overwhelmingly negative media coverage has turned governments off insulation altogether.
“Governments are really nervous talking about it,” he says. “It's really sad because although the fires were caused mainly by hot halogen lights, everyone's blamed the insulation. In Melbourne we were getting 40 fires a year from halogen lights. I felt the program was kind of hard done by.”
A recent study by the consulting firm Energy Efficient Strategies, commissioned by the insulation industry, estimates that the insulation installed under the program will have saved $4 billion in household energy costs and taken 10 million tonnes of carbon dioxide out of the atmosphere by 2020.
If the program were revived and extended to all the homes for which installation was planned before it was scrapped, the government could reap a further $1.5 billion in energy savings over 10 years, the report found.