Renewables use sun, water, wind; energy sources that won’t run out. Non-renewables come from things like gas, coal and uranium that one day will. But unless electricity and motorised transport is abandoned altogether, all ‘renewables’ need huge areas of land or sea and require raw materials that are drilled, transported, mined, bulldozed and these will run out.
Wind turbine towers are constructed from steel manufactured in a blast furnace from mined iron ore and modified coal (coke). Turbine blades are composed of oil-derived resins and glass fibre. The nacelle encloses a magnet containing about 1/3rd of a tonne of the rare earth metals, neodymium and dysprosium. Large neodymium magnets also help propel electric cars. Currently China provides 95% of rare earths, proven reserves of dysprosium will likely run out in 2020. Processing one tonne of ore, generates about one tonne of radioactive waste, 12 million litres of waste gas containing dust concentrate, hydrofluoric acid, sulphur dioxide, sulphuric acid and 75 thousand litres of waste water. Baotou, in China, mines and processes much of the rare earth ores. The town abuts a 5 mile wide, toxic, lifeless, radioactive lake of processing wastewater. Local inhabitants have unusually high rates of cancer (particularly in children), osteoporosis, skin and respiratory disease. This unseen environmental destruction may be far off but no less damaging.
One thousand tonnes of concrete anchors the turbine base. The concrete used for the 5000 or so built or consented turbines in Scotland would be sufficient to construct an eight lane motorway from John O’Groats to Lands End. Cement production generates 7% of the world’s emissions. Wilderness that is partitioned between turbines, access roads, crane pads and power lines is no longer renewable.
The Oxford University conservationist, Clive Hambler, has summarised data from Sweden, Germany, Spain, Denmark and USA that indicate one hundred birds are killed per turbine per year on average. For bats (that consume 3000 midges/night), it is two hundred. UK estimates for turbine wild life mortality are not available. But with 5000 Scottish turbines, premature destruction of birds and bats is in the million range/year. Organisations established by government to protect wild life in Scotland, are in denial over the damage their consent to wind farms is causing.
Current expenditure on UK wind farms is more than £20 billion. If that money had instead been used to construct 30 gas fired power stations to replace those using coal, emissions reduction would have been about 37%. Pristine countryside, reliable energy supplies and undamaged wild life would have been maintained. The present plethora of wind farms has only reduced emissions at best by 7.5%; necessary use of gas-fired back-up for reliable electricity supplies makes it less than 4% in practice.
The production of just 6 solar panels requires at least one tonne of coal to bake the silicon at high temperature. Solar panel-production plants generate 500 tonnes of hazardous sludge every year. Their manufacture releases hexa-fluoroethane, nitrogen trifluoride, and sulphur hexa-fluoride, greenhouse gases thousands of times more damaging than carbon dioxide. The life expectancy of solar panels and wind turbines is 1/2-1/4 that of gas fired or nuclear power stations. Even dams for hydropower (concrete again) are only scheduled to last 50 years. The low density of energy for both wind and sun requires huge areas of land for electricity generation. To replace the recently closed Cockenzie power station (1.2GW) would require turbines covering a minimum of 70 square miles of countryside. Geothermal energy requires fossil fuels/cement for power station construction. Power transmission requires cables made either of steel, copper (mined and processed) or even carbon fibre processed from fossil fuels.
Drax coal-fired power station generates 7% of UK electricity and has been partially converted to burning wood to benefit from government subsidies. A forest area substantially larger than Wales is needed for wood supply. But deforestation abroad to supply the wood threatens replacement of diverse ecosystems and wildlife damage with tree monocultures. When burnt, wood is dirtier than coal in releasing CO2, nitrogen oxides, carbon monoxide, particulates and organic volatiles. Up to 50 years are required to recover the CO2 emissions. Most biofuels produce some surplus energy over energy invested but with poor or negative emissions saving. Displacement of crop-growing land for biofuel forces food price rises.
Renewable energy is a myth; none will last longer than the non-renewable sources they all need. Uranium and thorium reserves should last thousands of years. Nuclear fission in small, fast-neutron, modular reactors generates electricity but waste that decays in 1-2 centuries. A breakthrough in the construction of small containment vessels for deuterium/tritium fusion has been reported. One kg of fusion fuel produces energy equivalent to 10 million kg of fossil fuel. Deuterium is abundant in the oceans. This is the future, not renewables.
Professor A J Trewavas, Scientific Alliance Scotland, 7-9 North St David Street, Edinburgh EH2 1AW
The Scotsman - December 2014