Better than Nuclear?
The Scientific Inquiry into Nuclear Energy has advocated that the Commonwealth legislate for at least 25 nuclear power plants to produce our energy needs for the future. They argue that nuclear energy is the cleanest form of power generation. It does not produce carbon emissions as does coal fired plants, and so does not contribute to climate change and worldwide pollution. It is also the cheapest form of power available, given that uranium is available in Australia. It is also the safest form of power generation possible and scores of nuclear generators operating around the world at this moment have the safest record of power production of any.
But some people object in light of the Russian failure of Chernobyl. That was a horrible example of wrong planning and poor construction. The most dangerous form of power generation is the mining and use of black coal. Thousands of miners and workers died in its production every year, not counting the horrific effects of climate change. Other people object on the basis of us not knowing how to store the waste. Since the 1960’s 400 nuclear reactors in 30 countries have produced 200,000 tonnes of waste. These are mostly stored in containers near the power plants themselves.
Nuclear reaction has been occurring on our planet for the past two billion years. The waste from the reaction remains buried deep underground. This waste is perfectly safe and inert. Central Australia is geologically stable and would be suitable for deep underground burial of waste. I have discussed these issues over the years with the doyen of Australia’s nuclear energy programs, Professor Les Kemeny.
However, public opinion, formed by forty years of protests make this an unlikely answer. Solar, wind and wave power cannot generate the base load of electricity we need (local people oppose the giant wind turbines at Crookwell), but it would take 50,000 such windmills to generate the required amount of electricity we need, and a steady stream of wind to keep them all turning. So apart from nuclear power plants is there any other alternative?
Have you considered hot, dry rock (HDR) geothermal power? HDR geothermal energy relies on existing technologies and engineering processes, and is the only known source of renewable energy with a capacity to carry large base loads.
The concept behind HDR geothermal energy is relatively simple. Heat is generated by special high heat producing granites located 3km or more below the Earth’s surface. The heat inside these granites is trapped by overlying rocks which act as an insulating blanket. The heat is extracted from these granites by circulating water through them in an engineered, artificial reservoir or underground heat exchanger.
HDR geothermal energy relies on existing technologies and engineering processes such as drilling and hydraulic fracturing, techniques established by the oil and gas industry. Standard geothermal power stations convert the extracted heat into electricity.
HDR geothermal energy is environmentally clean and does not produce greenhouse gases. It has been classified as renewable by national and international authorities. Currently, we pump 34 million tones of carbon into the air each year with growing worldwide problems, but geothermal power is self-contained and totally green as the HDR geothermal process is a closed system, with two loops.
The first loop uses water to extract heat from the buried hot rocks. The simplest hot dry rock power plant comprises one injection well and two production wells. Cold water is pumped under pressure down an injection well where it flows through an underground heat exchanger in the hot granite. It is then returned to the surface through production wells.
Because this loop operates under pressure, the super heated water remains a liquid, with no steam generated. The heated water (> 200 degrees celsius) returns to the surface under pressure. The high temperatures of the hot water are transferred to the geothermal power station loop via a heat exchanger. This second closed loop uses liquids with a low boiling point (similar to those used in fridges and air conditioners) and this drives a turbine system generating electricity.
The cooled geothermal water returns to the underground heat exchanger where it is reheated. The twin loop system is known as a binary geothermal power plant. The Cooper Basin in central Australia could generate enough electricity to meet the needs of all of Australia’s eastern states.
I have discussed this at length with my friend Martin Albrecht A.C., who is Chairman of Geodynamics Limited. Look for yourself www.geodynamics.com.au
Geothermal seems to be the way to go.
REV HON DR GORDON MOYES, A.C. M.L.C.