South Australia, a region without baseload and after a series of blackouts

South Australia was meant to be a global example of replacing baseload coal-fired power plants with renewable energy sources. The first blackout occurred less than five months later.

South Australia 

South Australia (SA) is one of the states of the Commonwealth of Australia. It borders Western Australia (WA) to the west, the Northern Territory (NT) to the north, Queensland (QLD) to the northeast, and the states of New South Wales (NSW) and Victoria (VIC) to the east. Its capital is Adelaide.

South Australia and renewables

South Australia has favourable natural conditions for the use of renewable energy sources (RES), particularly solar and wind power. The use of renewables has long been supported by political leaders. In 2007, it became the first state in the Commonwealth of Australia to set a legislative target for greenhouse gas reductions, and it was also the first in Australia to introduce legislation enabling the preferential placement of solar power generation on the energy market. Emerging renewable technologies, backed by legislation and political support, rapidly gained laurels in the “race” with other sources, so that in 2014 the first working day was recorded on which the state was able to cover 100% of electricity consumption from solar and wind energy between 9:30 and 18:00, something widely exploited by environmental campaigners. At present, renewables account for roughly 50% of electricity generation. Last but not least, in 2015 the government declared a target for Adelaide to become the world’s first “carbon-neutral” city.

The indisputable successes in deploying renewables over the past decade reinforced feedback between the media-environmental sector and political leaders, which began jointly weaving ever more ambitious energy visions. Environmental and political pressure did not go unanswered in the banking sector. From the perspective of bank analysts, investments in maintaining coal power across virtually all of Australia became politically undesirable and therefore highly risky projects, naturally with corresponding impacts on projected lending interest rates for planned investments. The energy sector’s response was pragmatic: it abandoned further development, decided to “let existing technology run its course”, and redirected its activities towards other energy segments.

For some readers, this is probably a very positive and commendable development. But nothing comes for free, and as an engineer I will now outline some of the technical consequences.

Closure of coal-fired power plants in Australia

One consequence was the gradual closure of older coal-fired power plants on Australia’s eastern and southern coasts in recent years:

The end of the coal era in South Australia

The closure of Northern Power Station and Playford A in South Australia in May 2016 was accompanied by a generous dose of environmental and political propaganda, whose echoes reached Europe. The public was told through the media that this step marked the end of the era of coal-fired power plants operating in the baseload portion of the daily load curve in South Australia, and that the state would henceforth be reliably supplied by wind and photovoltaic power plants, supplemented by output from mid-merit and peaking natural gas plants, while any imbalance between domestic generating capacity and current consumption would be addressed by electricity imports from neighbouring states. From this perspective, the two interstate interconnectors with Victoria were to play a key role: Murraylink (220/132 kV HVDC) and Heywood (275 kV AC). Critical voices questioning this energy concept were dismissed as unqualified and churlish complaints from a defeated coal lobby that had been unable to respond to dynamic developments in renewables.

If only we had known in advance what would happen…

Last year, I came across an article of the optimistic-propagandistic type described above, published by Australian website REneweconomy in February 2016 (i.e. before the coal plants were shut down), with the prophetic headline, “Wind and solar replace coal in South Australia. But will the lights go out?”. I think it will be instructive for readers to become acquainted with some of the statements made at the time by responsible individuals and institutions:

• the Australian electricity market operator (AEMO) stated that South Australia was becoming a “world leader” in terms of the share of wind and solar electricity…
• Premier Jay Weatherill supported this trend and described it as an “experiment”…
• according to a report by AEMO and network operator ElectraNet, even very extreme and unlikely events that they are required to assess would not cause the grid to fail…
• AEMO identified no system security threats that could not be managed using existing procedures…

Blackout on 28 September

On this day, South Australia experienced a major blackout. The lights that, according to assurances made before the coal units were shut down, were never meant to go out, did indeed go out in 850,000 households…

The purpose of this weekend blog article is not to provide detailed technical information. I will limit myself to the most basic, simply presented facts, and refer other interested readers to the report of the inquiry:

• before the grid collapsed, South Australia’s demand was around 1,800 MW, covered by 883 MW of wind generation, 330 MW from gas and 613 MW of imports (Heywood and Murraylink); total domestic PV generation was estimated at 50 MW
• extreme weather conditions (tornadoes, lightning, hail) caused five system faults in the transmission system over 87 seconds, with three transmission lines tripping
• as a result of the above faults, six transient events involving rapid voltage fluctuations occurred in the grid, triggering the loss of 456 MW of wind generation capacity north of Adelaide
• the loss of generation from domestic renewable sources (wind) led to an excessive increase in electricity imports, specifically in the power transmitted via the Heywood interconnector from Victoria, which subsequently triggered its disconnection by electrical protection systems. The Murraylink line (I stress, HVDC) remained in operation until the total collapse of the system.
• as a result of the Heywood line outage, South Australia lost around 900 MW of capacity, while the remaining domestic sources were unable to meet demand
• the generation deficit was so large and rapid that the system operator’s under-frequency load-shedding schemes were unable to respond quickly enough
• the network operator was therefore unable, amid a shortage of domestic generating and above all dispatchable capacity, to disconnect load quickly enough and thereby save at least part of the grid from collapse; a severe imbalance between generation and demand therefore persisted, resulting in frequency collapse and total grid failure = blackout.

“Who is to blame”?

After the blackout, a media shootout erupted in South Australia in the style of “who is to blame” and “you see, renewables, we told you so”, whose echoes again sporadically reached Europe. At least they reached the author, who patiently waited for the publication of the inquiry’s final (fourth) report in order to present it to readers :-).

As for my personal view, the primary causes leading to the blackout were indeed extreme weather impacts, which is generally the argument put forward by renewable advocates. Put simply, in Europe transmission system elements are normally designed according to the N-1 criterion, occasionally N-2. This means that the system can withstand the loss of one or two elements, such as transmission lines. In South Australia, the network operator works with N-1, yet over 87 seconds it had to face an N-3 situation and accompanying transient events with significant voltage deviations – that was truly a “challenge”, evidently beyond its capacity or technical capabilities.

A strategic mistake

However, from a strategic perspective, I side with the “fossil lobby”. It argues that, by shutting down coal-fired power plants without adequate replacement – or rather replacing them with renewables such as wind and PV, while also relying on a very high share of electricity imports from neighbouring states – South Australia embarked on a path of irresponsible energy policy based on environmental propaganda or the wishes of “academic energy experts”, rather than on conservative technical foundations. This is also an “experiment”, though apparently not in the sense of Premier Jay Weatherill’s statement mentioned above…

In my view, if domestic conventional generating capacity had been increased – if not coal, then gas – these dispatchable sources could have mitigated the imbalance between renewable output and consumption; at worst, they could at least have switched to island operation and created “islands of stability” that might have supplied perhaps tens of thousands of households. Whether people like it or not, renewable sources have not yet reached a stage of development at which they can help a network operator when the going gets tough. The current situation is rather the opposite.

If only the lights had gone out in September…

Renewable advocates accuse their opponents of opportunism and malicious exploitation of an unfortunate situation, but after moving away from coal they have had to defend their interpretation of grid fault events in the media with disproportionate frequency. South Australia’s power system “climate” problems are not isolated. Here are several further examples from a government document:

• 9-13 July 2016: strong winds caused widespread outages affecting 120,000 households
• 27-28 December 2016: wind and high temperatures caused local outages
• January 2017: storms and lightning caused outages affecting 58,000 households around Adelaide
• February 2017: a heatwave caused a shortage of available capacity, despite conventional sources operating at full output, so AEMO ordered consumers to be disconnected – 90,000 households were cut off

A gas-fuelled lesson from the crisis

According to the information so far available from the South Australian government’s energy planit appears that political leaders have decided to adopt the stance of the clever Czech fairy-tale heroine. So everything concerning renewables is, of course, entirely in order, perfectly thought through, and the future will truly be magnificent. However, the text reveals a proposal for solving the acute energy mess. The government will finance, build and operate a 250 MW “state-owned gas power plant”, which will be brought online when needed – or, if you prefer, in an emergency – which will naturally affect its economic performance. In addition, in order to strengthen domestic gas-fired generation, the government intends to make use of extensive domestic gas reserves and open up production from promising fields. Environmentalists will probably be delighted.

Of course, the grave sin of a partly forced return to conventional energy will be offset by the future deployment of the most advanced technologies for large-scale electricity storage (for example here), and South Australia will once again be able to boast a global first in the field. We shall see with what results.

(Written for blog.iDNES.cz and oEnergetice.cz)