Australia takes a giant stride to save the planet from a fossil-fueled fiery end. The April 28 closure of the Liddell coal power plant in the state of New South Wales (NSW) by Origin Energy brings the amount of coal power taken out of the national electricity market to over 7 gigawatts (≈25 percent) since early 2012. And, we Aussies can say, proudly, not without considerable risk to ourselves. Though those in charge, in whose hands rests our earthly comforts, are forever reassuring us that the power supply is not at risk.
Are they protesting too much? We shall see as the great energy replacement unfolds in the weeks, months and years ahead. Bear in mind that the pumped hydro project Snowy 2.0 and the Kurri Kurri gas plant (which I describe here and here in a past pieces) were supposed to have been completed in good time to compensate for the closure of Liddell. And when will they actually be completed? Who knows? Mañana.
Origin Energy also owns Eraring in NSW, the biggest coal power plant in Australia, supplying close to 2.9 gigawatts of power at full capacity. It was due for early closure in August 2025. Now, as a result of the Australian Energy Market Operator (AEMO) warning of potential blackouts ahead, euphemistically described as “reliability gaps,” its closure is bound to be delayed.
The shape of things to come.
Chris Minns, new Labor premier of NSW, would prefer to avoid blackouts in his first term. And Brookfield Corporation, the prospective new owner of Origin’s energy business and therefore of Eraring, has responded by indicating its preparedness to consider delaying the closure. Brookfield is in the business of wind energy. A comparison calls:
Let’s compare one coal power station, Eraring, with the grandiose plans of Brookfield to install 14 gigawatts of wind and (grid-scale battery) storage at a cost of $20 billion in the next decade. Leave aside any questioning of the quixotic plan's practicalities, how does one coal power plant stack up against all these planned turbines and batteries? It’s instructive.
Eraring consists of four 720 MW steam driven units for a combined output of 2,880 megawatts. Coal power can operate at a capacity factor of, say, 85 percent for the purpose of the exercise; note, it was 88 percent in Australia in the halcyon, bygone days of 2008. Hence, a well-maintained Eraring can put out 2,448 megawatts of more or less continuous power. I'll assume (we haven’t been told) that Brookfield’s 14 gigawatt project is broken down into 10 gigawatts of wind and 4 gigawatts of battery storage. The exact breakdown is not particularly material.
A favorable capacity factor for wind in Australia is around 35 percent. The average power output of 10 gigawatts of wind is therefore equal to 3,500 megawatts, more than enough to replace Eraring; on average, that is. Then there are four gigawatts (4000 megawatts) of lithium-ion batteries.
According to the U.S. Energy Information Administration (EIA), “when fully charged, battery units built through 2020 could produce their rated nameplate power capacity for about 3.0 hours on average before recharging.” On that basis, 4000 megawatts of batteries produces 12,000 MWh. However, I have seen estimates of 4.0 hours; giving, in that case, 16,000 MWh. To be fair, I’ll take the more generous estimate. Note, that would be equivalent to running Eraring for 6.5 hours (16,000/2,448) before the batteries run flat. Adequate, it might be wrongly thought. Think correctly. Factor in wind droughts.
Let a million meters bloom.
Friend of mine and wind watcher Rafe Champion extracted data compiled by AEMO, measuring the output from some 70 wind farms and over 2,000 turbines across South Eastern Australia. He took the month of June 2020 as his sample. He found the following:
Low points [when supply was one tenth or less of plated capacity] lasted for 33 hours on the 5th-6th, 18 hours on the 11th, 16 hours on the 17th, 14 hours on the 26th, 11 hours on the 27th and nine hours on the 28th. There were several other lows of shorter duration, giving total of 13 episodes and much of the time during the low spells the supply was well below 10 percent, with lows of 3.4 percent, 1.1 percent and 2.3 percent during the most prolonged wind droughts.
Take the period when for 33 hours wind provided only up to 10 percent of its capacity. At most, that would mean a stream of just 1,000 megawatts coming from Brookfield’s 10 gigawatt turbine extravaganza. That is 1,448 megawatts short of Eraring’s output, which let’s suppose is needed to keep the lights on. How long would the gigantic 16,000 MWh of battery storage last? Just 11 hours (16,000/1,448). Sadly, unless you have a diesel-powered generator at the ready, blackouts for you ensue for 22 hours.
To be clear about what we have here. One single coal power station occupying 0.6 square miles (total project area 3.6 square miles) bests 10,000 megawatts of wind and 4,000 megawatts of storage. That’s two thousand wind turbines, assuming each has capacity of, say, 5 megawatts (well above average), occupying in the order of 1,000 square miles plus batteries of over thirteen times the size of Australia’s biggest battery, the 300 megawatt battery in Victoria. And all costing, so they optimistically say, $20 billion to build. Including high-voltage transmission infrastructure to carry electricity from far-flung wind farms? Hardly. That’s the taxpayers’ job.
Don’t be nervous. She’ll be right, mate. These environmental blokes from the government are bound to know what they’re doing.