Our new study corridor

The new study area means 98 private landowners in the existing 1km-wide corridor will no longer be impacted. The new study area initially includes around 105 new private landowners; however, this number will reduce as we refine from a 3km-wide study area to a 1km-wide corridor. It’s too early to say how many landowners will be within the 1km-wide corridor, however we expect the overall number of impacted landowners will reduce further.

There are unavoidable impacts by updating the corridor, including a revised development program for the project. This is necessary to make sure we can complete a robust assessment of the project for environmental planning approvals and allow more time for community engagement. 

Timing changes are part of delivering complex projects. While the development timeline may take longer, the updated corridor will make the project easier and faster to build. 

We are now expecting to lodge the EIS in the second half of 2026 with indicative planning approvals in 2027. 

We previously advised that the New England REZ would deliver 6 gigawatts (GW) of network transfer capacity by 2034 through the first two stages. This will allow up to 12GW of new renewable energy generation to connect to the grid by the mid-2030s.

It is still too early to know the exact delivery date for the REZ, however we are working to understand this as we engage with industry in the network operator procurement process.

We will keep the community informed about further updates to the planned energisation dates as more information becomes available.

EnergyCo’s previous 1km-wide study corridor partially followed the existing 330kV transmission line corridor between Muswellbrook and Tamworth.

While co-location with existing transmission lines can help consolidate impacts to a local area, further detailed technical assessments found that co-location in these areas is problematic due to steep terrain, increasing constructability risks, environmental impacts and safety risks.

The existing 330kV transmission line was first built in the 1960s and uses the best available locations in the area. That means our two proposed 500kV lines would be located in more challenging areas, typically on land that is steeper and harder to build on, requiring more earthworks.

Some locations next to the existing lines presented extremely challenging terrain where access had significant high grades for long lengths. In these locations, non-conventional construction techniques such as heavy-lift helicopters would be needed to build the lines due to the access constraints. However, helicopter usage is further constrained due to safety risks of construction next to a live high voltage line.

While this may be technically feasible, the new study area we’ve identified would provide better overall outcomes with reduced impacts for construction, local roads and the environment.

The existing 330kV transmission lines that currently transfer power between Bayswater, Tamworth and Armidale, and between Armidale, Kempsey and Newcastle, are operated by Transgrid. They are not suitable for the large amounts of energy to be transmitted for the New England REZ and are running near full capacity.

We considered if the existing lines could be upgraded to meet the capacity requirements for the REZ, however this option was excluded early in the evaluation process due to a number of constraints:

• high construction impacts as the existing lines would need to be taken down, easements widened, and new infrastructure built.

• lengthy power outages during construction which would have a major impact on energy users and the operation of the National Electricity Market (NEM).

• increased impact to regional centres along the existing route which have experienced major growth since the lines were first built.

For these reasons, upgrading the existing lines was not a preferred option for the REZ and is not being considered further.

In August 2024, EnergyCo reviewed the Aberbaldie-Niangala travelling stock reserve (TSR) as an alternative corridor option for the New England REZ transmission lines following requests from the local community. The key driver of this request was to maximise the use of public land by using the TSR itself.

The TSR was assessed through EnergyCo’s typical route selection and change management process including a multi-criteria analysis based on our planning pillars and principles. EnergyCo’s assessment found an alignment following the TSR provided less favourable outcomes against multiple criteria, most notably impacts to private landowners. The TSR was not progressed on this basis.

This assessment found that placing the alignment exclusively within the TSR would have significant impacts including proximity to homes, high conservation value biodiversity within the TSR and the surrounding area, impacts to Biophysical Strategic Agricultural Land (BSAL) and the requirement for increased vegetation clearance.

While the new study area is located in the vicinity of the TSR, it is not positioned entirely within it. This approach helps to avoid the constraints and impacts that are outlined in the TSR assessment report.

The TSR assessment report identified that the area surrounding the TSR offers more favourable terrain, improved accessibility, and better bushfire management. The new study area takes advantages of these favourable conditions in the nearby area. To view the TSR assessment report and FAQs, visit EnergyCo’s website.

The New England REZ has an expected network capacity of 8GW. This is a significant amount of energy to be transported from the REZ south to Bayswater, requiring twin 500kV double circuit transmission lines along the bulk corridor in an overhead configuration.

Some of the challenges of underground cables at this capacity include:

• Construction: Underground cables suitable for the high voltages required for long distance transmission would be much larger than the conductor or wire used in overhead lines, and much more complex to install. They are larger and heavier than equivalent capacity overhead lines and are typically installed in large, deep trenches which have a very high construction impact.

• Cooling and thermal management challenges: Underground transmission lines accumulate heat in the surrounding soil due to poor natural dissipation. The underground cables could not operate at full planned capacity without costly active cooling systems such as forced ventilation or fluid cooling. The scale and cost of implementing such cooling systems over long lengths of corridor would be immense and would introduce ongoing operational risks.

• Time and cost: Construction would be long and costly due to the extent of trenching and specialist procedures required to lay heavy cable without causing cable damage. This means that meeting energisation targets using underground cable technology would be extremely challenging, even if cost were not an issue.

• Repairs and maintenance: Underground cables need ongoing maintenance to function effectively. When cable failures occur, average repair times are significantly longer than those for overhead lines. Specialised skills, plant and equipment would be required, and large areas of excavation may be required to identify the fault, resulting in longer repair times and interruptions to energy supply.

• Environment and land use impacts: Underground transmission lines are unsuitable in complex or sensitive areas such as rivers, cliffs and Aboriginal heritage sites, while overhead transmission can more readily avoid or minimise impacts to these areas.

The limitations of undergrounding have been addressed in a Standing Committee on State Development Inquiry on the feasibility of undergrounding the transmission infrastructure for renewable energy projects (Parliament NSW, 2023), as well as the Select Committee on State Development Inquiry on the same topic. You can read more by searching ‘undergrounding’ at parliament.nsw.gov.au.

High voltage alternating current (HVAC) and high voltage direct current (HVDC) are different systems used for transmitting electricity. Globally, overhead lines are standard practice for 400-500kV HVAC transmission lines like those proposed for the New England REZ.

Typically, HVDC is suitable only for transferring bulk electricity point-to-point over very long distances. It is not suitable for networks that require new generation to be readily connected, like the New England REZ.

HVDC would require large and costly converter stations to convert power for connection into the existing NSW grid as it uses HVAC technology.

Using underground HVDC transmission for the New England REZ would pose significant challenges due to the long distances and would require more infrastructure to be built, which would greatly increase construction impacts, duration and costs.

This would include using large trenches, about 20m wide, over the full length of corridor which would need to be wider and deeper in areas with undulating terrain due to the need for cabling to have a minimum depth and limited bending. This means it is not a feasible solution for the project.

For information on the New England REZ, please visit our website or contact the project team.

Email: nerez@energyco.nsw.gov.au

Phone: 1800 061 114 (toll free)

Website: energyco.nsw.gov.au/ne