From The Age - pity he didn't mention we can use the heat from...

From The Age - pity he didn't mention we can use the heat from power plants in Coldry production!

So much hot air, and there's so much we can do with it
Andrew Lang
July 21, 2009
ANY government will normally try to avoid getting into hot water. However, in the case of changing to a low-carbon energy policy and achieving reduction of greenhouse gas emissions, experience has shown that the more hot water the government gets into the better.

Australia has the distinction of being among a small and dwindling group of nations — China, Poland, Russia — that produce the great majority of their domestic and industrial energy from coal, usually in massive power plants producing only electricity. This inefficient production of energy, along with inefficiencies in house design and an overuse of private cars for transport, is what puts us in the top bracket of per-capita greenhouse gas emissions.

By one measure, our national emissions are 24 tonnes of carbon dioxide per person, and are at least triple those of Sweden or Denmark, and double those of Britain or the average resident of the European Union countries.

One of the reasons these countries have a far lower figure is because they use less energy per person. The other is that they make far better use of the heat produced along with electricity.

Power stations that generate electricity from steam-driven turbines normally will produce about twice as much heat energy as electrical energy. Here we waste all of this heat energy, and so for each tonne of coal burned in our condensing power plants, we get only about 35 per cent of the energy in the coal as electricity. Because these power plants are large and often at great distances from consumers, energy losses from transmission line leakage can be up to 15 per cent. Then up to half this electricity is promptly converted back to heat in households and industry.

Heat is normally the cheaper form of energy, but not when it's produced in this way.

In Sweden, by contrast, the heat energy from combustion is almost totally captured. It is circulated in insulated pipelines as heated water around large and small communities close to the power plants.

At each business, hospital, apartment block or house, heat energy drawn off as the hot water passes through a heat exchanger is measured and charged for. When all the heat from combustion is being used, the fuel conversion efficiency of a power plant is 80 to 90 per cent.

Many of these power plants are small and provide only what is required locally, or by smaller towns and villages. Those near cities and large towns produce more heat and electricity, with the excess electricity going into the national grid.

Sweden and Denmark are not alone. The European Union overall has only about half the per-capita emissions of Australia. In addition to greater use of heat energy, the EU countries are making far greater use of by-products from their agriculture, forestry and timber processing industries, and are using sorted municipal solid waste as an energy fuel.

Recycling and public transport infrastructure all help reduce their emissions.

Australia could be doing all this. We have dense urban populations and we produce a lot of waste that ends up in landfill. Discarded wood can be chipped and used as fuel, along with soiled paper and packaging. We have large areas of forest, plantations and farm land producing agricultural and forestry residues: biomass that should be used for producing energy.

The combination of all this underused material could be producing 5 per cent of our energy needs within a few years and at least 20 per cent within 20 years. Our governments and energy industry must value and use heat energy and learn from countries that use municipal solid waste and biomass as energy fuels.

Andrew Lang is a board member of the World Bioenergy Association and represents the South Pacific region including Australia and New Zealand. He is chairman of SMARTimbers Co-operative.