The “other” big battery that has quietly changed thinking about the grid

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Another big battery has been changing the way people think about the grid, proving that thermal generators are not required to provide inertia, and eliminating blackouts. Now, everyone wants one.

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There has been a huge amount of interest in, and a huge amount written about – particularly on this website – the success of the Tesla big battery in South Australia.

But another big battery, the Newman battery storage project, installed just over a year ago in a private-only grid in the Pilbara serving mostly mining industry customers in Australia’s north-west, is having just as profound an impact on the way people think about the grid.

The 35MW/11.4MWh Kokam lithium-ion battery was installed in September last year by Alinta, next to its 178MW Mt Newman gas-fired generator, which supplies mining operations such as Gina Rinehart’s Roy Hill facility. But not much has been said about it until it applied for, and won, a major engineering award.

The reason was simple. Like the Neoen/Tesla big battery, the Newman battery has shown that it is faster, smarter, cheaper, and more reliable than the fossil fuel generators around it.

In this instance, the battery has done what most experts thought it could not do – provide sufficient inertia to the local grid in the absence of thermal generators. “There is no real difference when compared to mechanical (rotating mass) systems,” the compact says.

And its speed of response has all but eliminated the supply interruptions that were relatively common in the small grid that relies on comparatively slow gas generators. And it has led to a significant saving on “back-up” gas generation.

“It is the first, as far as can be determined, utility-scale battery energy storage system to provide grid-forming services on a high voltage network,” the citation for the WA Excellence in Engineering Award reads.

“Until now, the conventional thinking had been that electrical networks needed thermal generators to be online and operating to provide the required inertia to support the network. Thanks to this significant milestone in electrical engineering, that is no longer the case.”

You hear a lot about the so-called “reliability” of “baseload” fossil fuel generation. But the reality is that they need a lot of back-up in case of failures, which are frequent.

In a big grid, that goes largely unnoticed, but in small grids like the Pilbara it stands out. The Mt Newman gas facility consists of four different units, and usually two of them are needed to back-up another. Not so now, with the new battery.

Gary Bryant, Alinta’s head of asset strategy, gave a rare presentation about the battery at the recent All Energy conference in Melbourne, and RenewEconomy followed up with a phone interview last week to find out more.

According to Bryant, the Newman battery can do at least three things that were previously not seen with such installations: it can operate in standalone mode, it has grid-forming capability, and can provide frequency control by acting as a virtual generator.

It’s the ability to provide enough fault current to keep the grid stable whenever everything else goes pear-shaped that has proved the most valuable. The nature of such grids means that generators can be lost, and large loads can be lost.

“We have had situations where we had no thermal generators, and the battery’s been able to hold the transmission line by itself,” Bryant says.

And the same thing has occurred when up to 80 per cent of load is suddenly lost. “The battery has responded within milliseconds,  absorbing the excess load until the system restabilises to ensure no loss for other customers,” Bryant says.

Previously, because of the slower response of the gas generators, cascading losses were often unavoidable. “We’ve definitely had fewer outages – our customer’s very happy with improvement of power quality,” he says.

Is Bryant surprised? Not really. The Alinta team travelled to South Korea to look at that country’s considerable deployment of battery storage, and choose the set-up that suited the Newman site best.

And he says there is a huge amount of interest in what it’s achieved.

“It is changing the way everyone is thinking about these operations,” Bryant says. “The industry, generally, is starting to look at these things being genuine options to reduce gas consumption and maintain system strength and power quality.

“We’ve had a lot of interest from miners – from the petrochemical industry, and from grid operators. We’ve had AEMO (the Australian Energy Market Operator), and quite a number of meetings with technical and policy advisors (from different governments).”

And he says there is no doubt that battery storage is now the technology of choice. Everyone wants one.

Woodside is looking to do a similar project – but on a significantly smaller scale – for an offshore oil rig. That will be 1.5MW/1.5MWh  but will reduce the number of gas turbines needed. “The costs of servicing those are horrendously expensive,” he says.

Alinta is also looking at another battery storage facility, particularly if it goes through the grid expansion that it is contemplating, which will see possibly two different 60MW solar farms added to that network – quite an extraordinary shift in thinking for mining grids.

“As that network is pushed out further it is inevitable we will put in a second unit, but that also depends on how much renewables we put on the grid,” Bryant says.

We are looking at extending out network beyond Roy Hill, and using solar as much as we can. The more (solar) we put there, the more we need system security.”

Batteries, though, are the ultimate compromise. Big machines are slow to recover in frequency events, and low inertia machines – while fast and able to arrest decays in frequency – are unstable. Batteries offer a solution to both deficiencies.

Interestingly, Kokam, the providers of the battery, will be fully owned by inverter technology provider Solar Edge following a $US88 million purchase announced last week.

Note: The original specifications of a 30MW battery storage capacity was upgraded to 35MW after completion of the installation.

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