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We don't know why South Australia's wind farms stopped working, so hold off on the blame game
Australia’s energy ministers are meeting today in an emergency gathering following South Australia’s recent state-wide blackout.
The blackout, following wild weather across the state, has seen an extraordinary response from politicians and media, implicating the state’s wind energy in the fault.
On Wednesday the Australian Energy Market Operator (AEMO) published a preliminary overview of the blackout (known in the jargon as a “black system” event). This document reported first observations based on data available to up to Monday this week.
Importantly, the report concluded that the “root cause is subject to further analysis being conducted”, as further information becomes available. As the chief operating operator Mike Cleary made clear, “at this stage we cannot apportion blame”.
What does the report say?The report provides a detailed chronology of the events that occurred in South Australia and led up to the state-wide blackout, and the restart process. This includes details on the three transmission lines lost and changes in generation output.
Here’s a shortened summary of the timeline:
Fault on first transmission line: one high-voltage line out of service
Fault on second transmission line: two high-voltage lines out of service
Loss of 123 megawatts of wind power
Fault on third transmission line: three high-voltage lines out of service
Loss of a further 192 megawatts of wind power
Flow on the Heywood interconnector (which links South Australia with Victoria) increases above limit
Heywood interconnector trips off
Torrens Island and other power stations trip off
Supply lost to South Australia.
The time between the second transmission being out of service and the loss of supply to South Australia was approximately eight seconds. A total of 315 megawatts of wind generation disconnected during the this period.
Frequency and VoltageA unique characteristic of electricity systems is that supply and demand must match instantaneously in real time. If they do not match, the frequency and voltage of the system can deviate from an ideal value. In Australia, AEMO maintains the frequency at 50 hertz (Hz).
Deviations from this value (from sudden changes in supply or demand) can substantially damage equipment. Automatic protection equipment activates to “trip” generators offline.
As the report noted:
generating units are unable to operate (and are not required to do so) where frequency is below 47 Hz. With the frequency below 47 Hz, generating units subsequently tripped off line.
This is likely to be how Torrens Island gas plants and other plants were disconnected from the system, after South Australia was disconnected from Victoria.
Is this why the wind stopped generation?The report also suggests that:
The magnitude of transmission faults due to weather in a short period of time, resulting in significant voltage dips and loss of load, resulted in system instability. This caused some generators to reduce output, increasing flow on remaining power system equipment, causing power system protection to operate to remove risk of damage.
However, the report makes it very clear that “insufficient analysis has presently been undertaken to determine if everything operated as designed during the event.” Crucially, additional analysis is required to determine the reasons for the reduction in generation and observed voltage levels before any conclusions can be drawn.
At this stage, it is unclear if the wind farms tripped off because of voltage dips or other reasons. Other reasons could be related to the extreme storm events, such as a lightning strike. The answer at this stage is we don’t know.
What we do know is that the loss of supply from the transmission line faults and the decrease in wind output caused the flow on the Heywood interconnector to increase to approximately 850–900 megawatt – above the interconnector’s design limits. The system protection kicked in (in less than a second) to trip the Heywood interconnector, and the rest followed.
Is this scenario unique to wind?A very similar situation in South Australia in 2005 saw a massive blackout when a lightning strike caused a dramatic decrease in brown coal-fired in Port Augusta, with the Northern power station reducing output to 0 megawatt.
This created a similar surge in interconnector flows from Victoria, which ultimately resulted in disconnection from Victoria. Several other generators in South Australia also tripped off as result of this incident, and wide-spread blackout occurred.
The recent storm was was particularly extreme, with reports of 130,000 lightning strikes hitting the state in a matter of hours. The reality is that all parts of the power system are vulnerable to such extreme weather and lightning storms.
Indeed as noted in the AEMO report, one of gas turbines contracted to provide system restart service in South Australia was also affected by the recent storm.
What can the energy ministers do?The federal energy minister Josh Frydenberg called an urgent meeting of Australia’s energy ministers in light of the recent blackout.
The role of interconnectors to provide better links across the National Electricity Market as well as battery storage have been reported to be on the agenda of Friday’s meeting.
Increasing transmission was also the focus of a recent energy council meeting, where energy ministers agreed to review of the regulatory test for investment for new transmission assets.
A formal review into the National Electricity Market will also be up for discussion. This may include a review of the National Electricity Objective, which forms the basis of energy policy decisions, and does not include environmental considerations, such as the need to reduce emissions.
Given the increase in moisture and heat expected from climate change, one way that the state and federal governments can help ensure there is not a repeat of blackout is by agreeing to significant emission reductions.
![The Conversation](https://counter.theconversation.edu.au/content/66631/count.gif)
Dylan McConnell has received funding from the AEMC's Consumer Advocacy Panel and Energy Consumers Australia.
First deal to curb aviation emissions agreed in landmark UN accord
Global scheme, agreed to by 191 nations, applies to passenger and cargo flights that generate more than 1,000 tonnes of greenhouse gases annually
The world’s first agreement to curb aviation’s greenhouse gas pollution has been struck by 191 nations in a landmark United Nations accord, although environmental groups have warned the deal doesn’t go far enough.
A meeting of 2,000 delegates at the International Civil Aviation Organization (ICAO), a UN agency, in Montreal has settled upon a global emissions-reduction scheme that will apply to passenger and cargo flights that generate more than 10,000 tonnes of annual greenhouse gases.
Continue reading...Intensive farming v the environment | Letters
If we were to redesign the farm financial support system so that, instead of encouraging agro-industrial approaches, it required recipients to practise the sort of agro-ecological methods advocated by Felicity Lawrence (Hyperintensive farming will never feed the world, 3 October), we would be able to re-conceptualise it as not a “subsidy” or “welfare payment” (Letters, same day) but a management fee for essential ecological services. After Brexit, we will in principle have the opportunity to do this. But will Mrs May and Mrs Leadsom see things this way?
Richard Middleton
Castle Douglas, Dumfries and Galloway
• In the early postwar years, Monsanto’s William Rand claimed that the chemical industry was a form of alchemy, unmatched in its dynamic power and therefore entitled to protection from criticism of its products’ potential dangers. Willard Dow, of Dow Chemicals, regarded the industry’s critics as “traitors to civilisation” and “economic parasites destined to destroy themselves”.
Continue reading...World needs $90tn infrastructure overhaul to avoid climate disaster, study finds
Report by Global Commission on the Economy and Climate says world needs ‘urgent’ shift away from carbon-heavy infrastructure over the next 15 years
A gigantic overhaul of the world’s buildings, public transport and energy infrastructure costing trillions of dollars is required if dangerous climate change is to be avoided, according to a major new report.
The study by the Global Commission on the Economy and Climate, which is co-chaired by prominent climate economist Lord Nicholas Stern, found that the world is expected to invest about $90tn in infrastructure over the next 15 years, requiring an “urgent” shift to ensure that this money is spent on low-carbon, energy-efficient projects. Such smart investment over the next two or three years could help ameliorate the climate crisis, but “the window for making the right choices is narrow and closing fast”.
Continue reading...Scotland bans controversial gas extraction technique
Ministers heed expert advice warning that underground coal gasification poses ‘numerous and serious’ risks to the environment and climate
Scottish ministers have banned the use of a technique to extract methane by burning underground coal beds, after expert advice said it posed too many risks to the climate and environment.
Paul Wheelhouse, the Scottish environment minister, said he was asking ministers in London to revoke six licences to find test sites for the technique, known as underground coal gasification (UGC), in central and south-west Scotland.
Continue reading...Copter cars and other visions of Africa’s future
'He’s rewriting the rules': locals furious at minister's fracking intervention
Campaigners in Lancashire say Sajid Javid’s decision to overrule council is an affront to local democracy
In Heather Speak’s immaculate back garden in the Lancashire village of Roseacre, the only sound was the tranquil rustling of trees and the singing of the budgerigar, finches and miniature Chinese quail in her aviary.
But a gloomy atmosphere hung over the picturesque village on Thursday after Sajid Javid, the communities secretary, overturned Lancashire county council’s rejection of plans for a fracking site on its doorstep, saying he was “minded” to permit the drilling if Cuadrilla provided evidence on road traffic issues.
Continue reading...