Facts & Figures

• Energy resources can be described as renewable and non-renewable. Renewable energy sources are those which are continually being replaced such as energy from the sun (solar) and wind. If an energy resource is being used faster than it can be replaced (for example, coal takes millions of years to form) then it will eventually run out. This is called a non-renewable energy source.

• In Australia hydro power is currently the largest source of renewable energy for electricity generation (over 8% of total supply) and is expected to retain this position, although its share is projected to drop to about 6% by 2019-2020. Most of this hydro power is from the two largest plants, the Snowy Mountains scheme and the Tasmanian Hydro-Electric installation.

• Wind energy is the fastest developing renewable energy source in Australia. This trend follows the growth in wind farms in other parts of the world.

• Solar energy is Australia’s largest energy source: the average amount of solar energy that falls on Australia is about 15,000 times the nation’s energy use. In all parts of Australia, except southern Victoria and Tasmania, solar resources are good to very good. Sunlight can be used to generate electricity, provide hot water, and to heat, cool and light buildings.

• Each renewable energy source has unique characteristics, making them suited to a wide range of purposes, sites and situations. In general they are all better for the environment than non-renewable energy sources, and technological advances will continue to assist in reducing the negative impacts.

• Greenhouse gas emissions could be halved by 2040 if governments chose to replace ageing coal-fired power stations with renewable sources such as wind and solar, according to research by the Australia Institute, the Sustainability Centre and Energy Strategies.

• A recent paper by the Australian Greenhouse Office found emissions from the energy sector in 2020 will have shot up by 160 per cent on their 1990 levels.
8 A shift in the world’s energy use is inevitable within the next 50 years – the timeframe predicted for the exhaustion of oil and gas resources. Hydrogen will be the likely hero, storing energy via a number of processes, including those based on renewable sources.

• Our power consumption today is nearly ten times the level of 1960, and more than double that of the early 1980s. And that growth is showing no sign of slowing, with Australia’s demand forecast to top 225,000 gigawatt hours by 2010, up from 173,000 gigawatt hours in 2000-01 – a 30 per cent rise. Another 30 per cent increase to nearly 300,000 gigawatt hours is forecast by 2020.

• Coal will remain the prime source for most of our electricity in the future, but a rising proportion will come from gas and renewable energy, as technology evolves to make them more competitive.

• The constraint for raising the use of solar energy is that it is costly and not particularly efficient, as existing technology converts only around one tenth of the sun’s energy into electricity.

• Challicum Hills wind farm in the west of Victoria – Australia’s largest wind farm – alone creates enough energy to power the equivalent of more than 25,000 homes.

• A hydroelectric power plant uses a renewable source of energy that does not pollute the environment. However, the construction of dams to enable hydroelectric generation may cause significant environmental damage. Also, water used to drive the power plant could have other uses at other times, for example, for irrigation or town water supply.

• Hydro power is the leading source of renewable energy. It provides more than 97% of all energy produced by renewable sources. Other renewable sources – solar, wind, biomass and geothermal – account for only 3% of the energy produced.

• Burning biomass fuels still releases greenhouse gases like carbon dioxide into the atmosphere. In some cases, where stronger greenhouse gases would otherwise be emitted, there is a greenhouse benefit. In others, where the product could have other benefits rather than being burned for energy, other energy sources would be better for the climate.

• Of all the renewable forms of energy, geothermal, wave and tidal energy are least likely to be used in Australia. This is because, unlike the requirements for solar power, we don’t have many suitable sites. However, geothermal energy has been used very successfully in a small number of countries that have the right conditions.

• Both ethanol and biodiesel produce less pollution than mineral equivalents but they are very different substances. Petrol engines need modifications to run on a mix of more than 20 per cent ethanol and unmodified engines can be damaged by it, according to its critics. However, most diesel engines can run on straight biodiesel or a blend without any mechanical changes. And while ethanol has less energy per litre than petrol, biodiesel is on a par with its more familiar rival.

• Proponents ... see hydrogen not just as an alternative energy source, but as the foundation of a whole new non-polluting economy ... Renewable energy sources such as wind and thermal power would be used to split water into hydrogen and oxygen. The hydrogen would be run through fuel cells to create electricity that could power cars, homes, factories and transport systems. Exhaust fumes would be limited to water vapour, eliminating some of our greenhouse problems. But ... hydrogen always combines with other elements when left to its own devices. So you have to manufacture it by breaking down the substances – such as water, coal or gas – where it is stored. The problem is that this process generally uses as much energy as the hydrogen it produces gives out.