Features Australia

Renewables becalmed

7 July 2018

9:00 AM

7 July 2018

9:00 AM

As Australia’s electricity grids strain to cope with demand and government efforts to foist yet more renewable energy on them, consumers can at least be thankful that down under weather patterns are different from those of Europe where the wind does not blow for days.

In mid-June, Bloomberg reported that virtually no power had been generated by the nation’s wind farms for about nine days, with calm conditions expected for another two weeks.

It is summer in Britain and demand is low, but analysts are now concerned over what will happen during a similar clam period in winter, particularly as the atmospheric lows that occur in the region often combine calm conditions with arctic cold.

This is an intractable problem for UK Greens dreaming of a fossil fuel-free future, as it is simply not possible to build enough batteries or pumped hydro capacity (dams) to supply Britain’s grid for days at a time.

Weather patterns are different in Australia, but just how different is difficult to work out as there has been almost no proper discussion of the issue. One site which sheds some light on this point by tracking energy demand and supply by source over Australia’s eastern sea-board, including South Australia and Tasmania, is Aneroid Energy run by weather forecaster Andrew Miskelly.

Like previous compilations of such figures for Australia, site statistics for April, May and June show that wind does not stop blowing across the region for more than perhaps two days at a time, rather than more than two weeks as occurs in Europe – but does display a distinct, irregular, saw-toothed pattern of strong supply followed by periods of calm.

In the first half of June, to estimate from the graphs on the site, existing wind farms supplied less than 500 megawatts continuously for a total of perhaps three days, including one two-day period, and at other times peaked at or above 3,000 megawatts. The now vast numbers of rooftop solar installations add another 2,000 to 4,000 megawatts or so in distinct, sharp daytime peaks, falling away to nothing at night. That substantial output variation of between almost nothing to perhaps 7,000 plus megawatts has to be properly managed to fit into total demand that varies between 18,000 and 26,000 megawatts each day. This is usually done by directing the operating gas plants to throttle back whenever the wind blows and the sun shines.

As can be seen even from those sketchy figures, boosting green electricity so that it supplies 50 per cent of demand, as some state targets require, and activists repeatedly call for, will require a major additional boost.

At the moment the renewables, when they are all acting together, do not add up to half of the minimum daily demand (which of course occurs at night) So to reach the 50 per cent target, the grids will require not just vast additional investment in renewables but also either additional gas peaking plants, or some form of energy storage for the two days plus when nature takes a break. No one is building gas plants and the only dam proposal is the Prime Minister’s Snowy 2.0 option, which is expected to have 350,000 megawatt hours of storage when it is completed in the late 2020s. That is a good start but it is still less than a day’s worth of electricity for the eastern grid (WA has a separate grid).

In the meantime, with no new conventional capacity being built, the eastern grid is struggling to keep industrial users supplied. In mid-June, due to unplanned outages in the state’s coal-fired plants and low output from renewables, NSW’s Tomago aluminium smelter turned off three of its potlines to avoid paying soaring electricity prices.

Despite these obvious difficulties discouraging industrial investment, the media still quotes activists claiming that there is no real problem, that the combination of coal plant outages and lack of renewables production is ‘rare’, and that power from renewables is really cheaper than that of conventional power. In one story, an analyst stated that green power could be bought on long-term contracts at perhaps $40 to $50 per megawatt hour, which is well under the ruling state wholesale price of $60 a megawatt hour. However, as is common in such stories, there was no mention of the renewable energy certificate generated by each megawatt hour, required by the Renewable Energy Target legislation.

In early June, the megawatt hour Large-scale Generating Certificates cost a substantial $82.50 each (there is a separate certificate for rooftop solar). That additional amount has to be paid by someone, almost always the consumer. Faced with such costs it is little wonder that Tomago managing director Matt Howell has called for more investment in base-load (that is, reliable) generators.

While Australia digs itself deeper into its energy policy hole, the quest for expensive ways to store cheap green electricity continues, with the commissioning of a plant near Manchester in England to store energy by liquifying air.

As is common in such stories the media is too busy breathlessly explaining the concept to mention costs and investment, but the plant stores 15 megawatt hours of energy and the financing included an £8 million ($A14.2 million) government grant. Highview Power, which runs the plant, also states that the plant stores energy at half the cost of a lithium-ion battery, without troubling to mention the costs of using batteries, and that the plant will last forty years, compared with ten for a battery.

As the installation’s capacity would have to be multiplied by at least 1,000 to make the slightest difference on the Australian grid, let alone in the UK, consumers here are looking at $14 billion plus worth of investment just for starters, to even out the bumps in renewable power production.

Snowy 2.0 will cost perhaps one third of that but regardless of the storage route taken, cheap green electricity has the capacity to ruin us all.

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