For over a century, the basic principles of our electricity supply changed very little, with small numbers of large (mostly coal-fired) generating plants reliably delivering electricity to distant users over a carefully coordinated transmission and distribution grid.
In recent years, the electricity generation system has changed dramatically.There are now almost 1.7 million rooftop solar photovoltaic (PV) installations in Australia. More than 2000 wind turbines currently feed electricity into the national grid.
Wind and solar PV combined contribute almost 7 per cent of the nation’s electricity.This seems set to continue growing, especially as large solar-farms come online. Every single major committed electricity generation project in Australia at present – over $5 billion in commercial investment – is in renewables.
At the same time, around three-quarters of Australia’s aging fleet of coal-fired generators are operating beyond their original design life. Eraring power station is set to close by the early 2030s. Origin Energy, the owner of Eraring, will not invest in any fossil fuel assets in future.The trend from fossil fuels to renewables is clear. But there are also clear signs that the present grid (the National Energy Market) is poorly suited to the task of facilitating the transition of our national electricity system away from old coal-fired generators to energy sources such as wind and solar.
In South Australia, where over 40 per cent of that state’s electricity last year was supplied from renewable sources, recent state-wide blackouts have highlighted well-recognised problems with renewables.
There is a pressing need for a national energy transition plan. Government policy intervention is needed to provide certainty for investors looking to deliver reliable and affordable modern electricity solutions.
Solar and wind power is now cheaper than old power sources.But using intermittent renewables means investment is needed in systems and technology for storing electrical energy.
The SA government has proposed building a $1 billion solar-battery farm. Battery storage on this scale would probably have prevented the February 8 power outage to more than 40,000 homes in SA.
Just days later, Prime Minister Turnbull unveiled Snowy 2.0, a $2 billion plan to expand the Snowy Hydro scheme into a massive energy store – a giant battery – by using cheap, off-peak (renewable) electricity to pump water uphill, where it can be used to regenerate electricity when it is needed and expensive.
Pumped hydro storage relies on simple physics. A national plan to stabilise and decarbonise our electricity sector by mid-century is proving much more difficult.Intermittent solar and wind electricity generation demands greater network coordination, and almost certainly large-scale energy storage. While no single technology will solve that problem, grid-scale energy storage is one part of a secure future electricity supply.
A decade ago, in frustration with the heated and wordy debate on sustainable energy policy in the UK, the late physicist Sir David MacKay coined the phrase “We need numbers, not adjectives” in his hugely influential book Sustainable Energy – Without the Hot Air. To which we can safely add: “We need long-term policies, not just numbers.”
Associate Professor Steven Weller is with the School of Electrical Engineering and Computing at the University of Newcastle. He will be speaking with Professor Behdad Moghtaderi at the Newcastle Institute’s public forum at Souths Leagues Club on Wednesday at 6pm.