TransGrid has recently published a Project Specification Consultation Report (PSCR) for maintaining reliable supply to Bathurst, Orange and Parkes areas in Central West NSW.
As set out in TransGrid’s 2020 Transmission Annual Planning Report, the latest demand forecasts indicate that electricity demand is expected to increase substantially in the Bathurst, Orange and Parkes areas going forward. This is mainly due to expected demand growth of some existing large mine loads in the area, the planned connection of new mine/industrial loads and general load growth around Parkes, including from the NSW Government’s Parkes Special Activation Precinct.
TransGrid’s power system studies forecast that the expected load growth in the Bathurst, Orange and Parkes areas will reach voltage stability and thermal limits of the 132 kV supply network in the Central West area if action is not taken.
Schedule 5.1.4 of the National Electricity Rules (NER) requires TransGrid to plan and design equipment for voltage control to maintain voltage levels within 10 per cent of normal voltage. The NER also requires the power system to be operated in a satisfactory operating state, which requires voltages to be maintained within these levels, both in normal operation and following any credible contingency event.
TransGrid has undertaken planning studies that show that the current Central West network will not be capable of supplying the combined increases in load in the area without breaching the NER requirements and that voltage-limited constraints will have to be applied in the 132 kV supply network if action is not taken.
Moreover, in addition to the longer-term voltage constraints identified, the planning studies show that the increased demand will also lead to thermal constraints in the Central West region of NSW, particularly during times of low renewable generation dispatch in the region.
This RIT-T examines network and non-network options for relieving these constraints going forward to ensure compliance with the requirements of the NER and provide the greatest net benefit to the market.
TransGrid considers there are four broad types of credible network options that have the potential to meet the identified need from a technical, commercial, and project delivery perspective. Each of the credible network options outlined in this PSCR requires a new 330/132 kV substation near Orange and a 132 kV line to Orange North to provide the required supply capacity to meet the forecast load growth in the Bathurst, Orange and Parkes areas. Aside from the new 330/132 kV substation near Orange, the credible network options differ by where, how and when new capacity is added to the central west region in the near-term. In particular, TransGrid currently considers there to be four broad types of credible options, which cover:
- a new 132 kV line between Orange and Parkes;
- a new 330 kV line between Orange and Parkes;
- dynamic reactive support at Orange and Parkes for as long as it can meet forecast demand, following which a new 132 kV line between Orange and Parkes is required; and
- batteries to provide both load reduction and dynamic reactive support, following which a new 132 kV line between Orange and Parkes is required.
TransGrid considers that non-network solutions may be able to form credible options for this RIT-T, either as standalone options or in combination with network options (or components of these options). Together with this PSCR, TransGrid has released an Expression of Interest (EOI) to provide additional detail on the technical requirements for non-network options and seek submissions from proponents of these options. Details for access to the EOI are available via TransGrid’s website.
TransGrid welcomes written submissions on materials contained in the PSCR. Submissions are particularly sought on the credible options presented and from potential proponents of non-network options that could meet the technical requirements set out in the PSCR. Submissions are due on 17 June 2021.
In accordance with the requirements of the Rules, a summary of the PSCR is made available on the AEMO website. A copy of the PSCR can be obtained from TransGrid’s website or by emailing regulatory.consultation@transgrid.com.au.