I do find it somewhat curious the questions that I hear from some of the sceptics of the paradigm shift to our new energy economy.
People often ask me about purchasing an electric vehicle (EV) and the first question inevitably relates to the number of kilometres before battery replacement. I guarantee no salesperson for an internal combustion engine vehicle (ICEV) has ever been asked how many kilometres a car will travel before the engine needs replacement. And here is the rub. EV batteries slowly degrade over time but, on average, they will last significantly longer than an engine. A recent survey in Europe reported users with 350,000km on their EVs with capacity still above 90 per cent. Even if you had 500,000km on your vehicle, it is unlikely the battery will just stop working, it will just have reduced range. And this is with zero maintenance required of the battery. Try driving an ICEV with zero maintenance and see how many kilometres before you need to replace the engine.
The next intriguing example relates to wind farms. The first statement I often hear about wind farms is that they are terrible for the environment because the blades will have to be buried at the end of their lifetime. Is that it? Is that the best reason you can come up with to keep burning coal? The average lifespan of a coal-fired power station is 29 years. I rarely hear people ask what we will do with the old power station at the end of its life.
The expected lifetime for a wind turbine is up to 30 years. Ten Mile Lagoon in Western Australia was Australia’s first commercial wind farm of note having been established in 1993. It is still operating now and could keep operating for a number of years.
The 9 turbines produce just over 2MW. Modern wind turbines start at 3MW per individual turbine.
The turbines at Ten Mile Lagoon may soon be replaced with newer technology. The question then is what to do with the old turbines.
The towers that have stood tall for almost 30 years may be retrofitted with a new transformer, gearbox, blades etc. The tower may be replaced with a taller tower to take advantage of longer blades. Over 90 per cent of turbine component materials – such as steel, copper wire, electronics, and gearing – can be recycled or reused.
Except the blades.
The blades are typically made of a composite material consisting of glass fibre and plastic resin. Such composite materials might be light and strong, but they are also extremely hard to recycle.
Burying old blades is an option. After all, a single 3MW wind turbine will produce over 330GWh of electricity over its lifetime. The same amount of power using coal would require 172,000 tonnes of coal to be burnt.
But to modern problems there are people working on modern solutions. One collaborative research project in Europe is developing a method of recycling blades to be used in cement co-processing.
But more exciting is the material that new blades may soon be made from. Scientists have developed a material that combines glass fibres with plant-derived polymers. This composite resin can be recycled more easily than current materials. At the end of its useful life, the resin can be easily dissolved which releases the core components to be used again in an infinite loop.
You can even recover food-grade potassium lactate which can be used to make gummy bears!
Now there is a solution I can live with. Renewable power production that I can then eat as a lolly!
Mathew Dickerson