Spotlight on: batteries

The dawn of the battery age

The rapid uptake of renewable generation in Australia – especially rooftop solar, which ANU notes is the largest per-capita in the world (PDF) – means our energy mix is evolving faster than ever.

The demand for energy throughout the day is marked by peaks and troughs – as the sun sets and people return home, there is a decrease in supply and swell in demand. That places more emphasis on sources of reliable energy that can provide electricity to the National Electricity Market (NEM) on demand.

The main sources of dispatchable generation across the NEM are coal and gas. However, there is a growing need for technologies that can store the excess of zero-emissions renewable energy produced during the day – the surplus solar and wind power – and then dispatch it at periods of higher demand and lower supply.

Wandoan: thinking strategically

Increasingly, large-scale battery storage is becoming economical as the cost of batteries decline and the technology to use stored energy in a more dynamic way improves.

In January, AGL announced that one of Australia’s largest grid-scaled batteries would be built at Wandoan, 400km north-west of Brisbane in Queensland. The Wandoan Battery Energy Storage System, or BESS, will have a 100 MW capacity, and store 150 MWh of energy – enough to power up to 57,000 average homes.

BESS will be built and maintained by energy infrastructure developer Vena Energy Australia, and AGL will have full operational dispatch rights for 15 years.

The Wandoan BESS is part of our broader strategy to support the transition from coal generation to renewables with flexible storage and generation.

Last year we partnered with Electranet to deliver the Dalrymple 30 MW ESCRI battery on the Yorke Peninsula in South Australia and in October, we announced a deal with Maoneng Group to contract capacity from four 50 MW, 100 MWh large-scale batteries in NSW at a fixed price. The Maoneng batteries will be operational from 2023 and store enough energy to power up to 30,000 homes.

This is in addition to current development work to build a 50 MW battery at Broken Hill, which would support the AGL’s Silverton Wind Farm and Broken Hill Solar Plant and provide improved reliability to the Broken Hill region.

Supporting the grid

It’s important to note that grid-scale batteries are not just designed to dump energy into the grid and power homes. Some batteries can act in what is known as ‘island mode’, which provides electricity to homes when the main supply is lost and while power is being restored.

However, one of the main benefits of grid-scale batteries is to provide grid stability. Due to their response time – measured in the milliseconds – grid-scale batteries offer fast-response to support the stability to the grid when something goes wrong, such as when generators or transmission lines fail.

Take for example the large-grid scale battery project in Victoria that we announced in November. Part of plans to develop an 850 megawatts (MW) multi-site, integrated battery system, this development will continue to firm up capacity for years to come.

Small-scale battery storage

Residential-scale batteries also have a significant part to play in this dynamic, by lightening the load on demand when energy use is at its peak, which is usually just as the sun is going down.

For example, through use of smart battery software, customers could choose to use their stored energy at times of the day when electricity is in greatest demand (and at its most expensive). This is typically in the evening peak and using batteries this way, individually or cumulatively takes strain off the Grid.

A cumulative view of small-scale battery storage

AGL’s Virtual Power Plant is a good example of the benefits of small-scale battery storage from a cumulative view. In September last year, we completed the installation of the 1,000th battery in our Virtual Power Plant (VPP) and the impact is a combined 5 MW of energy, drawn and orchestrated from the interconnected energy storage systems of homes and businesses in Adelaide, in a smart network that supports the grid.

Energy storage story just beginning

The potential benefits from energy storage are huge – but we are currently only seeing the beginning of this transition.

As storage options become more economical and are integrated more and more into the NEM, the future grid will be more productive over time, leading to lower costs for customers and less emissions from dispatchable coal and gas-fired generation.

This is the dawn of the battery age…

Batteries in the mix	Capacity	Status
Dalrymple ESCRI (SA)	30 MW	Completed
VPP (SA)	5 MW	Completed
Maoneng (NSW)	200 MW	Expected completion 2023
Wandoan BESS (QLD)	100 MW	Expected completion 2021
Broken Hill (NSW)	50 MW	Proposed