Co-generation

Cogeneration – how it works

Burning fuel in power plants usually ends up producing more heat than electricity. Coal-fired power plants are typically only 30% efficient in converting the energy of the fuel into electricity, with the rest of the energy lost as waste heat. In addition further energy is lost in transporting the electricity often vast distances to where it is actually consumed in homes and businesses – the losses in transporting the electricity are often as high as 10%. In addition, the electricity network – the poles and wires – that transport power are very expensive. Over the next five years Australia will spend over $24 billion dollars on upgrading and growing Australia’s electricity network.

However there is a more efficient way to produce electricity. Smaller, gas-fired power plants can be located nearby to customers, where the heat as well as the electricity can be usefully employed. This achieves significantly improved energy efficiency - above 70% is typical – and is known as cogeneration or co-gen.

Cogeneration power plants can also reduce the amount of costly electricity network infrastructure required to transport electricity to where it is needed as the power plants are located right near customers.

Greenhouse gas savings

Cogeneration power plants have a third of the emissions associated with producing electricity from coal power plants and the increased efficiency resulting from cogeneration means less greenhouse emissions.

In Australia

Australia has 2667 megawatts of installed cogeneration power plant capacity, with much of it used in heavy industries such as metals, paper and chemicals.

Potential

There is potential for significantly more cogeneration in Australia. There are a number of industrial plants, as well as commercial and residential facilities and buildings, which, for example consume gas and electricity to produce heat and steam for general heating, water heating, and run production processes.

Cogeneration could supply the heat and steam needs while at the same time producing electricity much more efficiently with significantly lower greenhouse emissions. Gas used in more efficient cogeneration power plants is a major opportunity for low-cost greenhouse abatement in Australia through improved energy efficiency. It could also provide major savings through reducing the more than $24 billion planned to be spent on networks over the next five years.

Global view