IAN KIRKWOOD: Why batteries or a bigger Snowy are not the answer

GIVEN the vexed state of our power supplies, it is little wonder that older readers are pining for the old certainties of the past.

WATER INTO ELECTRICITY: Extra capacity from Snowy Hydro is seen as one way of bolstering the power grid. But what happens in a drought? Picture: Chris Lane.

WATER INTO ELECTRICITY: Extra capacity from Snowy Hydro is seen as one way of bolstering the power grid. But what happens in a drought? Picture: Chris Lane.

As one letter to Fairfax Media put it this week: “Remember when the price of electricity was not an issue, the government owned the generators and the electricity commission ran the show?”

To answer the question, I do remember those days, because my first five years out of school were spent in the employ of the commission, first as an apprentice and then later as a mechanical fitter in the power stations.

And while I do think we did a pretty good job of bringing power to the people back then, it was by no means a trouble-free system. Indeed, in 1982, my final year with the commission, 100 or so of us were sent in to get the White Bay power station in inner Sydney re-started, because problems with some of the newer and bigger power stations meant we were importing power from Victoria – a political no-no in those days.

White Bay was a tiny station by modern standards. Its two generators had a combined maximum output of 100 megawatts. Earing and Bayswater can each put out more than 2500 megawatts. So it made little difference in real terms, but it made it look like then-premier Neville Wran was doing something about the shortage, much as Prime Minister Malcolm Turnbull wants to be seen now, with his talk of battery farms and pumped hydro.

The biggest problem with the Australian power grid is that our most obvious source of power, which is coal, is also public enemy number one when it comes to greenhouse gases and global warming. Although renewable power – especially photo-voltaic solar – has made enormous leaps in terms of output, cost and efficiency in the past decade, it is still hampered by its intermittent nature, which is at odds with the needs of a modern society for a rock-solid power supply. This reliability – White Bay moments excepted – is coal’s great attraction.

The need to solve the supply problem without going down the coal road has led to some grasping at straws, as we have seen this week with the Tesla battery plan and Turnbull’s push to add another 50 per cent to the potential output of Snowy Hydro.

The Tesla proposal is based around a battery farm that would be capable of producing 100 megawatt hours of electricity. That is, 100 megawatts of power for one hour, or 50 megawatts for two hours, and so on.

In other words, it’s the same size as White Bay, except that it runs out after an hour. And then it has to be charged up again from the grid: but at a time when the grid will be short of power, which is why the batteries are being discussed in the first place.

Which lead us to the Snowy, which is another version of the Tesla deal, but using the potential energy of water pumped to the top of a hill, rather than the chemical energy of a battery. Snowy Hydro says its hydro stations have a capacity of 4100 megawatts, producing about 4500 gigawatt hours of electricity every year.

Divide that figure by 8760 – the number of hours in a year – and you get an average output of 500 megawatts of power. Increasing that by 50 per cent adds another 250 megawatts of power. Again, not much, especially considering we lose 1200 megawatts when Victoria’s Hazelwood power station closes at the end of this month.

And when it doesn’t rain – which is often the case – then the Snowy runs dry.

In the end, there may only be two ways to keep the lights on: coal, or nuclear.


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