Plimer’s book has no pretensions of scholarship, since it lacks references, and its discussion of renewable energy is clearly not based on scholarly research by himself. He simply rehashes false myths, mostly originating in propaganda disseminated by supporters of fossil fuels and nuclear energy. These myths have been refuted again and again by experts in renewable energy. Here I'll address a few of Plimer’s howlers on wind and solar power. A serious error is Plimer’s claim that wind is "totally unreliable" and that "no carbon dioxide-emitting coal-fired thermal power station has been replaced by a wind farm". Actually South Australia has nominally two coal-fired power stations, several gas-fired power stations and many wind farms. As a result of the growth of wind generation to an annual average of over 27% of electricity generation, one of the coal stations is now shut down for half the year and the other for the whole year. Although gas capacity has not increased, the state’s electricity supply system is operating reliably. Clearly wind is partially reliable, despite its fluctuations. Plimer then attempts to generalise his above incorrect claims to the notion that wind farms "cannot produce continuous electricity without coal, gas, nuclear, hydro or geothermal backup". This notion has been refuted by hourly computer simulations of the operation of large-scale electricity supply systems with 80 to 100% renewable energy in several countries and regions (reviewed in Chapter 3 of Sustainable Energy Solutions for Climate Change). These studies use actual hourly data on electricity demand and renewable energy supply, striving to balance supply and demand each hour over periods ranging from 1 to 10 years. For instance, our research at UNSW simulating the Australian National Electricity Market uses only commercially available renewable energy technologies (scaled-up wind, solar and biomass, together with existing hydro). We find that 100% renewable energy could have supplied electricity in 2010 with the same reliability as the polluting fossil-fuelled system. While we would not operate the grid on 100% wind alone, we could operate it on the above mix of renewable energy technologies with different statistical properties. Furthermore, using the Australian government’s own conservative projections to 2030 for the costs of renewable energy technologies, we find that 100% renewable electricity would be affordable. The relevant papers by Ben Elliston, Iain MacGill and myself, published in peer-reviewed international journals, can be downloaded from my UNSW website. In discussing the energy inputs needed to build a wind turbine, Plimer claims that "the correct figure for payback of just the embedded energy is probably more in the order of 15 to 20 years. Whatever the figure is ...". The weasel words "probably," "in the order of" and "whatever the figure is" suggest that Plimer is either guessing or misrepresenting the result and trying to cover himself. Actual life-cycle assessments find that, depending upon the site and type of wind turbine, the energy payback period (in terms of energy, not money) is actually three to nine months! Plimer greatly exaggerates the land use and associated environmental impacts of wind farms, by taking the land they span and misrepresenting it as the land they occupy. Wind farms actually occupy only 1% to 3% of the land they span. They are normally erected on agricultural land and it's rare that a single tree is cleared. They bring supplementary rental income to the farmers who host them (typically $8000 to $10,000 per turbine per year in Australia), and increasingly bring financial benefits to local communities. Other errors and misrepresentations abounding in Plimer’s account include:
- The small subsidies to renewable energy under the Renewable Energy Target are not paid "even when a wind farm is shut down", because they are paid per megawatt-hour of electricity generated, not per megawatt of generating capacity.
- Furthermore, they are not paid by taxpayers, but by a tiny increase in retail electricity price paid by electricity consumers (except large consumers who have gained exemptions). This increase is offset by a decrease in wholesale price of electricity.
- Although Plimer correctly writes that "wind turbines can only extract about 45% of the available kinetic energy," he omits to put this into context: ordinary coal-fired power stations can only convert into electricity 30% to 40% of the energy stored in the coal.
- The best solar cells have efficiencies of around 25% (laboratory) and 21.5% (commercial), rather than Plimer's "not much higher than 10%".
- Solar power stations do not depend on floodlighting the mirrors to operate at night. Concentrated solar thermal power stations actually store part of the solar energy collected during daytime in tanks of molten salt, to generate at night.