Enhancing Energy Transmission: The Role of Battery Storage in Overcoming Network Challenges

Australia’s transmission network faces significant challenges as the country accelerates its transition to renewables. Congestion, efficiency loss, and intermittency continue to put a strain on the network, risking reliability and resilience. However, strategically placed battery storage offers a promising pathway to alleviate these issues and enhance performance of the grid.

Challenges in the Current Transmission Network

Transmission networks are designed simply to transport electricity from generation sites to consumption centres. Power flows in only one direction – from power plants it is carried through high-voltage transmission lines to substations, and then ultimately to customers. But Australian generation and consumption is changing fast, outpacing the county’s traditional grid infrastructure. The current power network is perfect for dispersing baseload power from traditional sources to a traditional customer base. But as the country transitions to renewables, the network has to deal with a far more complex supply-demand dynamic. 

Australia’s large-scale solar and wind generation is taking over an ever-growing share of supply when conditions allow it to do so. But its intermittent nature leads to sporadic under or over-supply. This intermittency means that the National Energy Market (MEM) still has to rely on gas or coal baseload or even more emissions intensive peaker plants to fill the gaps when the sun isn’t shining and the wind isn’t blowing.  

Australia’s home solar boom has also created a further challenge. In traditional grids, demand is relatively predictable and stable. But the stellar uptake of Rooftop PV by Australian households has massively changed the status quo. The NEM hit a new winter low of just 12,144 megawatts (MW) at 1pm on 24 August, as rooftop solar accounted for 46.5 per cent of the grid’s supply. In other words, households were still using roughly the same amount of energy but they weren’t buying it from the national grid. On one level this is a fantastic sign for Australia’s shift to renewable energy. But it has the knock-on effect of giving grid-scale producers a major headache over what to do with their surplus supply. In these circumstances large-scale renewable and traditional generators have two options – pay someone to take their output or simply switch off their operations. Both options are costly.

The answer to these problems is more battery storage so that excess energy can be soaked up during periods of over-supply and dispersed when demand rises. But to achieve this, countries like Australia need to take a strategic approach to rebalancing a transmission network geared towards top-down, one way power delivery.    

The Role of Battery Storage

By storing excess energy during periods of low demand or high renewable generation, batteries can discharge this energy when demand peaks or when renewable output drops. They also offer the obvious solution to growing curtailment concerns – providing an outlet not only for excess renewable generation but also surplus gas and coal supply. 

And big batteries are already having an impact. In South Australia one of the world's largest lithium-ion batteries has significantly improved grid stability and reduced energy costs for households. The battery’s fast-responding frequency control service has alleviated congestion and prevented outages, and its success has acted as a showcase for the role of battery storage to enhance grid resilience. Multiple new battery projects are now in development across the country but to be effective, these projects need to be coordinated strategically across the grid. 

Taking a strategic approach to Australia’s battery rollout 

There are encouraging signs of progress in Australia at the state and federal level. In states such as South Australia and Victoria, streamlined permitting processes and standardised interconnection procedures are reducing barriers to entry for battery storage projects while state governments across the country are looking to incentivise battery deployment through market mechanisms that reward the provision of grid services, such as frequency control and congestion relief. 

Strategic project collaboration between the public and private sector is also accelerating. Project EnergyConnect , a cross-state partnership between transmission operators ElectraNet in South Australia and Transgrid in New South Wales, is delivering a 900-kilometer high-voltage transmission line that will create a crucial link between the power grids of both states. A key feature of the project is its integration of large-scale battery storage systems along the transmission route. These batteries will play a crucial role in managing congestion and improving the efficiency of the interconnector. 

Battery developers themselves are also looking to be more strategic in how they plan for connection to the established grid. Pacific Green’s two current projects, the approved Limestone Coast Energy Park, and the planned Portland Energy Park, are both strategically located near operational grid infrastructure. At the Limestone Coast project, our 1.5 GWh battery system will connect straight into the 275 kVA South East Substation adjacent to the site, feeding into the Heywood Interconnector between South Australia and Victoria. In essence, the projects are being injected into a critical point in the network, creating a buffer which can mediate under or over supply. 

Grid developments like EnergyConnect, and storage projects like those at the Limestone Coast and Portland, show real progress in the future proofing Australia for the green transition. Long-term expansion and strengthening of the grid and strategic optimisation of current infrastructure will be crucial as more storage capacity comes online. If this can happen, then there’s no reason why Australia’s net-zero ambitions can’t be met. 

Joel Alexander, Managing Director and CEO, Pacific Green Australia will be expanding on some of the issues discussed in this article at the All Energy Australia Conference in Melbourne on 23 October. Attendance to this year’s event is free and you can register here.