De-carbonising Australia's homes

Despite contributing approximately 54 million tonnes of carbon emissions annually to the atmosphere, Australia's seven million dwellings currently have no role in the federal government's proposed Carbon Pollution Reduction Scheme (CPRS).

According to Professor Peter Newton from the Sustainable Cities Program at Swinburne's Institute for Social Research, this omission, plus the government's proposed compensation to households for the higher energy charges they will face once a carbon price is established, will effectively remove any incentive to reduce domestic greenhouse gas emissions.

"By failing to promote innovations in green building, distributed energy generation and energy-efficiency initiatives, the scheme will lock in poor performance of dwellings and wasteful behaviour by households," Newton said.

Newton recently completed a report for the federal and Victorian governments on ways to de-carbonise the housing sector. 'Hybrid Buildings: Pathways for Greenhouse gas mitigation in the housing sector' demonstrates the pathways that current 5-star rated project homes can take to achieve carbon-neutral or zero-carbon status.

The report also provides information little known to householders on how energy efficient existing types of housing and electrical appliances are and how they can upgrade to significantly reduce their domestic carbon footprint.

"Over 95% of Australia's houses currently reflect an operating energy rating of 2.5 stars or less," Newton said.

"Together with a worst case set of appliances they can be responsible for generating 45 tonnes of CO₂ emissions per house per year. This type of house represents the greatest challenge for a transition to carbon-neutral or zero-carbon housing.

"However, each dwelling in Australia has the potential for increased energy efficiency and utilisation of local energy generation."

The report proposes hybrid buildings as a means of winding back unsustainable urban ecological footprints and providing a basis for generating low emission or renewable energy from the built environment.

Hybrid buildings are defined as residential buildings that supply the annual energy requirements of their occupants for heating, cooling, lighting and appliances by generating their own energy. Available technologies include solar photovoltaic, wind turbine and solar hydrogen fuel cells as well as ground source heat pumps for heating and cooling.

At times when more energy is generated than is immediately needed by the household, the excess energy is sold to the grid and when more energy is required to run the household, it is bought back from the grid.

"The prospect of carbon-neutral or zero-carbon housing is technically possible for owners of 5-star energy-efficient homes who choose to add renewable energy devices such as solar or ground source heat pumps," Newton said.

"This could result in savings in CO₂ emissions averaging 11 tonnes per dwelling per year."