Over the past two years the family of five has managed to turn around the energy consumption of their 1950s double-brick Lyneham home from ''using electricity like it didn't matter'' to going carbon negative.

Under the Federal Government's Carbon Pollution Reduction Scheme package offered to the Opposition yesterday, householders would be able to make an individual contribution to reducing Australia's overall greenhouse gas emissions. Voluntary action by individuals would be taken into account by the CPRS, allowing the country to do better than the targets set for 2020 if households reduce their energy use and purchase green power.

The Driver/Fellows family has managed to reduce household emissions from 19t of carbon dioxide a year to minus 0.6t by installing a range of energy producing and energy saving devices, including a solar heater made out of 210 beer cans.

Mr Driver said the beer-can heater was enough to warm his home office during the day in winter, while a range of other alterations to their home meant they were now able to produce about double the electricity they needed, thanks to a 4kW photovoltaic solar system on the roof.

He was spurred into action after picking up a copy of leading environmental scientist Tim Flannery's book The Weather Makers. ''I was shocked, so I started looking at what I could do about the problem, and the best thing appeared to be reducing the energy use of our house.''

After organising an energy audit through the ACT Home Energy Advice Team, he installed sun shades on three sides of the house, replaced energy hungry appliances with more efficient ones and installed insulation throughout the home. During last week's heatwave temperatures inside the house reached a maximum of 25 degrees and the evaporative cooler on the roof has sat idle for the past two summers.

While the photovoltaic panels were a significant investment, Mr Driver said the majority of the reductions to the household's emissions came from simple actions such as sealing gaps and connecting electrical appliances to a powerboard that could be switched off when not in use.