A major renewable energy project planned for northern New South Wales has been abandoned after its developer, Alinta Energy, concluded that the project was no longer economically viable. The proposed Oven Mountain Pumped Hydro Energy Storage scheme was valued at approximately $1.8 billion and was expected to play a significant role in storing electricity for the state’s energy network. The decision was reported by ABC News on 22 October 2026.

The project was designed to provide up to 900 megawatts of electricity storage capacity. It was planned for a remote, mountainous area near Georges Junction at Carrai, approximately 60 kilometres south-east of Armidale and 75 kilometres north-west of Kempsey. The location’s steep terrain made it suitable for pumped hydro technology, which stores energy by moving water between reservoirs at different elevations.

Under the proposed system, electricity would be used to pump water uphill when energy was available. When demand increased, the stored water would flow downhill through turbines to generate electricity. This approach can help balance supply and demand, particularly when electricity generation from solar and wind farms fluctuates with weather conditions.

Reasons behind the cancellation Alinta Energy said economic and scheduling difficulties involving key project components, including a critical transmission line, had made the scheme unviable. The announcement followed years of technical studies, planning, engagement with stakeholders and development work.

The project had been progressing through the NSW planning assessment process and was regarded as an important potential component of the Armidale Renewable Energy Zone. Its cancellation therefore represents a setback for regional energy infrastructure and the wider transition towards renewable electricity.

Energy-market analysts have also highlighted the changing economics of electricity storage. Battery storage costs have fallen rapidly, while major civil engineering projects such as pumped hydro have become more expensive to construct. According to energy consultant Tristan Edis, building pumped hydro can cost roughly $5,000–$6,000 per kilowatt of output, compared with about $1,400 per kilowatt for a four-hour battery installation. These figures illustrate why developers increasingly compare long-duration storage projects against battery alternatives before committing substantial investment.

Impact on regional communities The decision has disappointed some local representatives who expected the project to create employment and stimulate regional investment. Construction would have required engineering, transport, equipment, earthworks and other specialist services. The project was also expected to support jobs beyond its initial construction period.

Armidale Regional Council representatives expressed surprise at the withdrawal, while local political representatives described the decision as a loss for the community. The remote location presents logistical challenges, including transporting machinery and connecting the site to high-voltage electricity infrastructure.

The area is also part of the traditional country of the Thunggutti people, meaning project development involved engagement with Traditional Owners and other local stakeholders.

Wider implications for Australia’s energy transition The cancellation highlights the difficulties involved in building large-scale renewable energy infrastructure. Australia needs reliable ways to store electricity so that power generated during sunny or windy periods can be used when generation falls or demand rises.

Pumped hydro can offer longer-duration storage than many conventional battery installations, but it often requires substantial upfront investment, suitable geography, lengthy planning and expensive transmission connections. Batteries can be installed more quickly in some circumstances and have become increasingly competitive as prices decline.

The Oven Mountain decision does not mean pumped hydro is no longer useful. Instead, it demonstrates that each project must compete on cost, timing, location and expected demand. The cancellation also raises questions about how energy developers, governments and regional communities can coordinate transmission infrastructure and planning decisions to reduce uncertainty.

For northern New South Wales, the immediate consequence is that a proposed major investment and its anticipated employment opportunities will not proceed as planned. For Australia’s energy sector, it is another reminder that achieving a reliable, lower-emissions electricity system will depend not only on renewable generation, but also on practical and financially sustainable storage solutions.