How the Tesla big battery became the “heartbeat” of Australia’s main grid

Neoen Australia, the owner of the Tesla big battery, or what they prefer to call the Hornsdale Power Reserve, has celebrated its first year of operation with a detailed report of the services it has delivered to the grid, and the savings to consumers.

The Tesla big battery – which at 100MW/129MWh remains the biggest lithium-ion battery in the world – was officially brought into service on December 1 last year, although it was actually operating a day or two before that.

Even Noeon executives say they did not realise just how good the technology would be, and they point to the savings, the speed and accuracy of its response, and its every-day role in maintaining grid security and, in some dramatic examples, how it kept the lights on.

“We always expected it to be fast … I didn’t expect it to be as precise as it is. It really is staggering,” said Garth Heron, the head of product development at Neoen at a special briefing for journalists at the Tesla store in Sydney on Wednesday.

The presentation by Neoen and from consultancy group Aurecon points to the estimated $40 million of savings to consumers from the battery’s everyday activities on the market – mostly in what is called the FCAS market (frequency control and ancillary services).

The graph above shows how it eliminated the spikes in FCAS that had been dominated and gamed by the incumbent gas generators. As we have written, the battery didn’t just smash that cartel, it eliminated the need to have the emergency FCAS at all.

More than that, the battery has played a key role in keeping the lights on in several key events, and now plays a front line role in the Australian Energy Market Operator’s management of the grid.

According to estimates published last week in RenewEconomy, using data from the Climate and Energy College, the battery likely delivered revenue of around $24 million in the first 12 months, mostly from the FCAS market and its $4 million a year contract from the state government to deliver grid security. 

This FCAS market, says Heron, plays a role a little bit like regulating the heartbeat. When frequency goes outside the normal band, FCAS is required to return it to normal.  

The battery has provided that service in a way that had not even been imagined until just a few years ago. And even though it accounts for just 0.2 per cent of FCAS capacity, its speed, accuracy and cost advantage has allowed it to capture 10 per cent of that market, and help reduce prices significantly along the way. 

“It has become enormously important in the FCAS market … it is regulating the heartbeat of the National Electricity Market,” says Heron (and it’s worth pointing out here that the NEM is the biggest man-made machine in the country).

The event on August 25, a day after Scott Morrison – the man who pilloried the battery as being as useful as the Big Banana – became prime minister was particularly important because it is now clear that the Tesla battery at Hornsdale kept the lights on in its home state.

It was the first and only time to date that the battery has operated at total available capacity to respond in an instant to a major event that threatened the stability of the entire grid.

First the battery responded to a major fall in frequency by injecting 70MW into the grid, and then as other states lost generation and had to shed load for households and big business in NSW, Victoria and Tasmania, and the connection to South Australia was lost, the battery switched to full charging capability in an instant – or 0.13 seconds to be precise – to keep the lights on in south Australia, where no load was shed.

“The human eye takes 0.3 seconds to blink. We can go to full output and back in less than the blink of an eye, “ Heron said. “It is remarkable. If that battery was not there, there could have been a real loss of power in South Australia.

“Once the interconnector tripped, it did a world first – going the other way into charging mode, to absorb some of the additional energy coming out of south Australia.

“It is the First time something like that has been done in the network. It’s always easy to drop load, quite different to switching it on all of a sudden.”

Paul Gleeson, who did the 12-month analysis of the battery for Aurecon, says the Hornsdale Power reserve is an example of the sort of step-changes that are required in a grid transitioning to a renewable-based system.

“It is inspiring to see what happens when you get an innovative approach and the courage to do something differently,” Gleeson says. 

“Innovation has allowed this to be a successful solution …. And a great outcome for the consumer as well as the system itself.”

“The thing that amazed most of us is the speed of response. It really is quite remarkable,” Gleeson said on the August 25 event.

“There is nothing else on the NEM that can do that yet … customers in South Australia were oblivious to what was going on, and that is what we want.”

Xavier Barbaro, the CEO of Neoen, said the company was enjoying “pushing the boundaries” of renewable energy, and is looking for more battery storage opportunities in Australia.

Its next will be at the Bulgana wind farm in Victoria, while other opportunities will be pursued in NSW and Queensland. Barbaro said it was clear that batteries, in the right situation, were competitive with other technologies, but as the Aurecon report highlighted, more work needs to be done to change the rules to reflect the multiple different roles that the batteries could perform.

Note: We will have a more detailed look at the Aurecon report tomorrow – we had to go for a test drive of a Jaguar I-Pace today, which we will report on in our EV-focused web-site The Driven tomorrow.