Extreme heat is a test. It tests people and the systems they rely on, not least the electricity system. So in a post-Hazelwood world, how will the national electricity grid cope during hot days as we seek comfort by cranking up our cooling systems?
It’s a summer’s day in 2018, and it’s bloody hot. It threatens to be the fourth day in a row the mercury will soar above 40 degrees.
It’s still early morning, but power-hungry air-conditioners are already working hard in Melbourne and across the eastern seaboard.
In the mid-1990s, about a quarter of ns artificially cooled their homes. It’s now more than half, with Victorians gobbling up about 80 per cent more electricity on a hot day.
As the climate control kicks in, home solar systems are also firing up. At the turn of the decade, rooftop solar panels were a novelty. Now, more than 1.5 million households have them. They provide some relief for the stretched electricity grid. And the grid needs all the help it can get.
Like most of us, electricity infrastructure struggles when it’s hot. This applies to the ageing equipment in creaking old coal plants and gas-fired turbines, with breakdowns more common as the heat rises.
Power lines sag, no longer capable of transmitting their usual load, lest they pack it in.
Even solar panels on people’s homes can lose nearly a fifth of their capacity as the temperature goes past 40.
When Hazelwood shut it became the tenth coal generator since 2010 to close. The closures took 5 gigawatts – more than three Hazelwoods – out of the grid.
Conversely, nearly 4 gigawatts of wind turbines have been connected, 5 gigawatts of solar rooftop panels installed and 3 gigawatts of gas-fired plants built since 2009 to cover peak demand.
These new sources are not a like-for-like replacement. Where coal plants run 24-7 and are inflexible, wind and solar energy are variable and need a flexible system in which different technologies are called on when needed. That’s where the grid is headed. But it’s not there yet.
The pressure on the regulator – n Energy Market Operator (AEMO) – to make the right calls about who will supply the power and where it is needed most during a hot day is immense.
There have always been occasional blackouts, but the febrile political climate is such that a loss of electricity will have nasty political ramifications for state governments.
If things go wrong, governments will be quick to pass the buck. And the market operator – which went out of its way to stress that in an emergency there was more than enough spare capacity to cover the loss of Hazelwood – is likely to cop the blame.
Knowing this, and fresh from being accused of not doing enough to prevent blackouts in South in 2017’s summer, the market operator took extra precautions. It urged generators not to schedule maintenance at peak times, and told two baseload gas-fired plants mothballed in northern Tasmania and Brisbane to help fill the gap left by Hazelwood. Both are up and running.
As demand rises, the regulator will also turn to “peaking plants” to supplement the generators that run every day. Hydro power and open-cycle gas (which differs from baseload gas) can ramp up quickly when a boost is needed in supply – and there is a willingness to pay a hefty price for the extra generation.
Victoria has a stack of peaking plants. Gas is expensive and the east coast supply is overwhelmingly being exported, but there is enough fuel for these plants to come online during a heatwave.
To help ease demand, some big industrial plants that use a stack of electricity have agreed to reduce their production to help keep the lights on. Aluminium smelters use more than 10 per cent of power generated in NSW and Victoria.
All things being equal, that should do the job. But there are other risks. Some power plants won’t be available.
Power plants are not compelled to make their generators available. During South ‘s 2017 blackouts one gas plant ran at about half its capacity.
That same summer also saw 2000 megawatts of coal, gas and hydro capacity out of action in NSW during a heatwave. In this instance, the market operator faced the difficult decision in relation to who would lose power. It angered the Victorian government by warning that power in Ballarat and Bendigo could be cut to keep NSW connected, though in the end it didn’t act on it.
As the heat rises, such decisions may have to be made if fossil-fuel plants fail or the wind doesn’t blow. Worse, the ever-present bushfire threat could knock out transmission lines or affect generators. What’s the extreme scenario? That all the risks arrive at once and blackouts, whether planned or forced, hit in some areas.
Victoria’s Hazelwood power station in Gippsland shut in March. Photo: Getty ImagesThe short-term fixes
Assuming the system is managed better than it has been in recent times everything should be fine, but experts also warn decisions made now will be crucial in ensuring reliability in the years ahead as more coal plants close.
The scenario above is the picture today, but it will almost certainly have changed again by next summer. The energy industry has been acting as though on fast-forward in recent weeks, and shows no sign of slowing down.
The Clean Energy Council says there is more than $5.5 billion worth of renewable energy projects under construction.
Last week, it was announced work would start this year on a $1 billion solar and battery plant in South . Billed as the biggest of its type in the world – it includes a 330 megawatt solar farm and 100 megawatt battery system – proponents say it could fix South and Victoria’s supply issue this summer.
This is independent of the the SA government’s quick tender for ‘s first large-scale battery system that could – if Tesla mogul Elon Musk is to be believed – be built in 100 days.
Tesla batteries connected to distribution circuits at Southern California Edison’s Mira Loma substation.. Photo: Jake Michaels
Less headline grabbing is SA Premier Jay Weatherill’s assurance that there will be 200 megawatts of emergency back-up in place. Almost certainly, it will be met by bringing in diesel generators.
This was the path Tasmania took when its hydro dams were running low and the Basslink cable to Victoria was broken last year. It might seem antiquated, but it works.
The Victorian government has also promised a battery tender, aiming to have 50 megawatts – enough to power a couple of regional cities for four hours – before Christmas. Another 50 is expected to follow in 2018.
Batteries and diesel can help deal with peaks, but Hazelwood’s daily output is likely to be mostly replaced by increased generation at NSW’s black coal plants, which have been running at about 50 per cent capacity.
Other promises – including Malcolm Turnbull’s proposal for a $2 billion expansion of the Snowy Hydro Scheme, and South ‘s pledge to support new plants to run government agencies and to build further gas-fired back-up – will take longer to be realised.
The Snowy Hydro Scheme at Talbingo, NSW. Photo: Alex EllinghausenUnanswered questions
The big, unaddressed question is what will the response be when the next large coal power plant closes – and the next one after that, and so on.
has 23 remaining coal generators. As the federal government acknowledges, several more may shut over the next decade.
According to modelling for the Climate Change Authority, all would need to be gone and replaced by cleaner technology by 2035 if is to play its part under the Paris deal to keep global warming below 2 degrees.
That notional deadline rarely gets a mention in public debate, but a campaign is in full flight for a bipartisan national energy and climate policy to set the pace for the transition to cleaner plants.
Businesses are worried that ageing coal plants will otherwise continue to shut abruptly – Hazelwood’s closure was announced just five months out – without there being time to build replacements.
The federal government has rejected their preferred model, an emissions intensity scheme, and has offered no alternative. Reviews into electricity security (by chief scientist Alan Finkel) and climate policy are under way, but the government is fundamentally divided on the need to do anything. It is hard to see where it lands.
Nationally, the only significant large-scale policy designed to drive energy investment beyond this decade is Victoria’s ambitious and contested renewable energy target, which aims to build enough wind and solar farms to deliver 40 per cent of the state’s electricity needs by 2025. The ACT also has a renewable target, but in other states the goals are purely aspirational.
Steam billows from the cooling towers at Victoria’s Yallourn coal-fired power station.
The Daniel Andrews government has not said what it thinks the rapid growth in clean energy means for the Latrobe Valley’s three remaining coal plants – Yallourn, Loy Yang A and Loy Yang B.
The state opposition plans to abolish the renewable target if it wins government next year but it hasn’t said what, if anything, it would put in its place. It has hinted it may subsidise coal plants to keep them open.
Meanwhile, anyone hoping for an answer on what will keep the lights on long-term is left waiting.
Adam Morton is on Facebook and Twitter.