NOTES ON SUSTAINABLE ENERGY: FROM THE ‘IN SEARCH OF SUSTAINABILITY’ (ISOS) INTERNET CONFERENCE

by Bryan Furnass 23 June 2003

Summary Australia is a world leader in per capita fossil fuel consumption and greenhouse gas emissions. More sustainable methods of energy production have been inhibited by government policies which have supported the mining industries at the expense of research and development in renewable energy technologies. We have the potential in terms of resources and expertise to become a world leader in energy sustainability through industrial development and lifestyle choices.

Australians, like other wealthy humans, use huge quantities of fossil fuel to produce and transport our requirements all over the nation and the world. We have become oblivious to our dependence on energy and assume our ‘modern’ lifestyle is sustainable. Production of oil will soon peak and the transition to renewable energy will involve a substantial reduction in energy use.

There is now a scientific consensus that since the nineteenth century, combustion of fossil fuels, together with extensive land clearing, has resulted in a steady rise in atmospheric carbon dioxide levels, which through an enhanced ‘greenhouse effect’ has led to global warming and consequent climate instability. This has profound implications for sustainability of both the environment and human health and wellbeing. Industrial agriculture, itself heavily dependent on fossil fuels, has also resulted in devastating land and water degradation, dry land salinity and loss of biodiversity.

Some of these issues were debated in the sustainable energy segment of ISOS conference. The keynote contribution was written by Professor Andrew Blakers, Director, Centre for Sustainable Energy Systems at the Australian National University, with seven supporting papers. The following outlines some of the points which were raised, with a focus on how Australia might evolve into a more energy-sustainable society:

1. Energy supply options

There are five available energy sources. These are solar energy, nuclear energy, fossil energy, tidal energy and geothermal energy. Of these, only solar energy can provide really large-scale energy in a sustainable and environmentally acceptable manner. Solar energy includes both direct radiation and indirect forms such as biomass, wind, hydro, ocean thermal, ocean currents and waves. Most of these energy forms will be part of the energy mix when solar energy becomes the dominant traded-energy form.

Tidal energy (from the moon’s gravitation) can be collected using what amounts to a coastal hydroelectric system. It is sustainable in the sense that it will not run out. However, the coastline is a scarce resource and the collection of large amounts of tidal energy will have a major environmental impact.

Geothermal energy has its origins in the decay of radioactive elements within the Earth. Heat associated with volcanic regions can be used to generate steam for district heating or to drive a steam turbine to produce electricity. Another form is “hot rocks”, which refers to hot masses of slightly radioactive rock buried several kilometres below the surface of the Earth. Cold water can be forced down to this rock, which is then fractured. Steam can be extracted from another borehole nearby. Geothermal energy is restricted to particular geographical locations. It is sustainable in that it can be harvested with limited environmental damage, although the heat stored in a particular place can certainly be depleted.

Nuclear energy from fission has severe problems relating to waste disposal, reactor accidents, nuclear weapons proliferation and nuclear terrorism. Nuclear fusion, with the potential of less radioactive waste is still many decades away from commercial utilisation, and is unlikely to be free of negative implications for nuclear weapons proliferation.

Fossil fuels (coal, oil and natural gas) are the principle cause of the enhanced greenhouse effect and are subject to resource depletion. Other problems include oil spills, coal mine accidents, oil-related warfare and pollution from acid rain, particulates and photochemical smog. The great London smog of 1952, in which several thousand people died of respiratory failure, led to the Clean Air Act and abolition of burning coal in open fires. Unfortunately, subsequent dependence on electricity supplies from coal-fired power stations in the East of England resulted in acid rain and massive forest destruction over much of Northern Europe.

2. Geosequestration of carbon dioxide

In Australia coal burning is by far the biggest source of greenhouse gas emissions. Almost all of these coal emissions come from coal-fired power stations, with the remainder coming from steelworks, alumina plants and cement works. Australia’s coal dependence is perhaps the main reason why the Federal Government refuses to ratify the Kyoto Protocol on preventing global warming.

Substantial government funding and policy support has been and continues to be towards trying to clean up coal, rather than committing resources to renewable energy production. One proposal, supported by the government and its chief scientific advisor is to collect CO2 during the combustion process in power stations, compress it and transport it in high pressure pipelines to long-term storage or ‘sequestration’ points in underground geological formations, such as depleted oil and gas wells, saline aquifers, and deep unmineable coal seams. This proposal carries a number of uncertainties:

· It is not known whether large volumes of CO2 can be safely stored indefinitely underground, although assessment is currently being carried out by the GEODISC group of the Cooperative Research Centre for Greenhouse Gas Technologies. One study has found that the largest storage potential is in West Australia, while the biggest point source emitters are in eastern Australia. There is no suitable store near the huge emission spot spanning the Hunter Valley – Lithgow – Port Kembla region, although there may be a store near the Latrobe Valley in Victoria. The study concluded that Australia has the potential to store about 100-115 Mt CO2 per year near large emitting sites. This is 19-20% of Australia’s total annual CO2-equivalent emissions or 26-30% of coal CO2 emissions.

· The permeability of storage sites to CO2 is not yet known. The main potential danger of underground storage is the risk of escapes of large volumes of CO2, leading to both global climatic and local environmental and health impacts. Since CO2 is heavier than air, the sudden arrival of a large volume of CO2 at a point on the Earth’s surface could result in low-lying areas near the breach filling with CO2 and people and animals becoming asphyxiated. This kind of event could occur from breaching either an underground store or an above-ground pipeline as a result of lack of knowledge of the store’s capacity, mistakes in operations, earth tremors or sabotage.

· The International Energy Agency (IEA) has calculated that the total costs of partially cleaned up electricity from a new coal-fired power station is 10.7c/kWh and 6.7c/kWh for a new natural gas combined-cycle power station (the cost of cleaning up CO2 waste from existing power stations would be higher). This compares with 8-10 c/kWh for electricity generated from large wind farms, which is expected to decline to 6-8c/kWh by 2010.

3. Solar energy options

· Solar energy can eliminate the need for fossil and nuclear fuels over the next 50 years. The key to mass – utilisation of solar energy is diversity. Indirect solar energy in the form of waves, ocean currents and hydroelectric sources are geographically limited. Hydro energy is usually associated with large environmental impacts arising from drowning of river valleys and the alteration of river hydrology. These energy options could contribute modestly in particular regions to an environmentally responsible energy supply.

· Biomass energy can be derived from waste materials such as sugar cane bagasse, garbage, sawdust and sewage. Firewood is another form of biomass energy. Unfortunately, the conversion of solar energy into chemical biomass energy has a very low overall efficiency (solar energy to chemical energy efficiency is less than 0.5%). When used on a large scale, biomass competes with food and timber production or with ecosystem preservation for the supply of arable land, water, pesticides and fertiliser. The notion that biomass can be grown on waste land with small environmental impact is incorrect. Vegetable wastes would be better used for compost formation to enrich the soil.

· Low temperature solar heat has the best potential for domestic energy needs. Good building orientation and design, which allows the use of natural solar heat and light, together with good insulation, minimises the requirement for space heating. Solar water heaters are directly competitive with electricity or gas in most parts of the world. In a residential college at the Australian National University, solar concentrator water heaters have been combined with photovoltaic collectors to produce 60% efficient hot water and electricity systems.

· Photovoltaics (PV) is an elegant but expensive technology. It has found widespread use in niche markets such as consumer electronics, remote area power supplies and satellites. Large numbers of PV systems are now being built on house roofs in cities. The cost of PV systems is not a strong function of scale, which means that PV systems are often the most economical energy source for small applications. About 85% of the world photovoltaic market is serviced by crystalline silicon solar cells. Electricity production from photovoltaics has been increasing at a rate of about 30-40% per year over the past five years, which is far in excess of the growth rate of energy consumption. Rapid growth in production is causing steady reductions in costs, which will eventually lead to a true mass market developing. The current value of annual PV system sales worldwide is about A$7 billion per year.

· The time required to recover the energy investment in solar energy equipment is typically one tenth of the lifetime of the equipment. One exception is photovoltaics, which currently has an energy payback time of about eight years compared with an expected system life of 20 to 30 years. However, the energy intensity and cost of PV systems is closely linked. Concentrator and thin-film PV systems are likely to have energy payback times of about two years.

· The Australian Government has committed tens of millions of dollars to fossil fuel research, with carbon sequestration being a particular focus. There are three Cooperative Research Centres for fossil fuels with total government funding of A$50 million. In November 2002 the Government made a grant of A$35 million to establish the Rio Tinto Foundation for a Sustainable Minerals Industry. This grant is about twice as large as Federal funding for renewable energy R&D over the past seven years. It could be said that the Government is more concerned to ensure short term sustainability of the fossil fuel industry than to develop a long term policy of energy sustainability for Australia as a whole.

4. Wind energy for sustainable development

· Wind energy is an indirect form of solar power. Global wind power capacity has quadrupled in the last five years, from 7,600 MV in 1997 to 31,000 MV by 2002 to become the world’s fastest growing energy source. Pollution free nature of the source, favourable economics and possibilities for enhanced fuel security and local manufacturing is driving the nations around the world to promote wind energy as a means of sustainable development. Europe continues to lead the development of wind power with 75% of the world’s installed capacity. Germany tops the table with 8000 MW installed capacity, using wind turbines with a hub height of 124 metres and a rotor diameter of 112 metres, rated at 4.5 MW.

· Power in the wind varies as the cube of the wind speed. Therefore the economics of wind energy depends to a great extent on wind conditions prevailing at the site. Some studies indicate the energy that went into the manufacture of wind turbine (the so-called cradle to grave energy use) is often recovered in 2 to 3 months in an average windy site. For a typical 20 year lifetime of the turbine, the turbine produces eighty times the energy used to build, maintain, operate, and dismantle it. Moreover, a single 750kW wind turbine prevents the emission of 1500 tons of CO2 p.a., as much as could be absorbed by 500 acres of forest.

· The 3000 km of southern coastline of the Australian continent contains a world-class wind energy source. Generally, the sea breeze is strongest in the mid afternoon when electricity demand is high. Several large scale wind farms have been installed recently and the Australian Wind Energy Association expects to have 1000 MW installed by 2010.

· Wind energy applications range from small battery chargers in remote dwellings to industrial scale turbines of a few megawatts capacity capable of meeting the electricity requirements of thousands of families. Wind energy is also being used in combination with diesel generators in several small, isolated electrical grids. These systems, commonly known as Hybrid Energy Systems have proved to be more reliable than a diesel genset, with a cost similar to that of diesel generation. Curtin University in Western Australia is working on a collaborative project with Westwind to develop a novel power electronic converter to enable small wind turbine generators to operate in variable speeds to increase energy production and improve system performance.

5. Lifestyle choices

· Political decisions and industrial applications can make a big difference in the move towards energy sustainability in Australia. Ultimately, the direction of changes will be determined by the community (as consumers and voters). The most important cultural adaptation, which is anathema to many economists, is that we must learn to consume less energy and energy-related products. Although this will slow economic growth (as measured by GDP) and reduce the market for material goods it may actually increase social capital and quality of life. Many sustainable behavioural changes could also improve health and wellbeing and reduce costs of medical treatment in the long term.

· One example of the excess personal energy intake over expenditure has been the doubling of the incidence the so-called metabolic syndrome of obesity and Type 2 diabetes over the past 20 years. Up to 30% of Australians over the age of 25 are obese, 19-25% of children and adolescents are overweight or obese. 8% of males and 7% of females suffer from Type 2 diabetes, giving an absolute prevalence of nearly one million. The metabolic syndrome is associated with more than half the cases of vascular disorders affecting the heart, eyes, kidneys brain and peripheral arteries, which account for considerable medical expenditure and loss of quality of life. Studies in children suggest that reduced energy expenditure, from increasing use of television and computers may be more important than excessive food intake in causing weight gain.

· There is plenty of scope for health practitioners (and general medical practitioners in particular) to devote more time to primary prevention and health promotion through nutrition and exercise education from childhood onwards. The present structure of Medicare provides little incentive for this to happen, since listening and advising is more time consuming (and therefore economically and perhaps intellectually less rewarding) than the traditional forms of disease care. It would make economic as well as humanitarian sense to make a greater proportion of the health dollar available for health education/promotion to reduce the spiralling hospital costs of end-stage diseases, many of which are potentially preventable through lifestyle adjustments earlier in life.

· Transport accounts for a major proportion of fossil fuel consumption, the most unsustainable practice being from single private cars being used for commuting, thereby causing increasing congestion, pollution and slowing of traffic flow through cities. Establishment of more public transport and bicycle lanes and the location of dwellings closer to workplace and public transport would encourage the building of regular exercise into the working day. A seldom recognised spin off from regular exercise is that apart from its role in promoting cardiovascular fitness it also enhances a feeling of mental wellbeing.

6. Further information

The keynote paper by Andrew Blakers is available on the website for the internet conference:

www.isosconference.org.au (click energy). If you want to read the supporting papers you will need to register ($10 for one month or $50 for the nine months of the conference. $35 concession). Other segments of sustainability which are being addressed are : water; human health and wellbeing; land use and natural ecosystems; equity and peace; economic systems; climate; labour force and work; transportation and urban design. A one day face to face conference, bringing together the ideas of contributing experts will be held at the Shine Dome of the Australian Academy of Science in Canberra on November 14. Early bird (Sept) registration for this is $50, through the website. It is hoped to publish a small booklet giving an integrated perspective of the sustainability contributions early in 2004.