30 June 2017 - powerlink.com.au

1 Generation Capacity Guide30 June 20172 Generation Capacity Guide30 June 2017 Generation capacity guide This guide provides indicative information about potential generation capacity which may be available at various locations across Powerlink s transmission network. The data presented is not comprehensive. It is a starting point, and is not intended to replace the existing processes that must be followed to seek connection to Powerlink s transmission network. The data has been prepared using the methodology and assumptions outlined in this document, noting that capacity is a dynamic concept that changes in response to real time network conditions, environmental conditions, and constraints. In practice, higher or lower capacities than those listed in Table 2 may be achievable at different points in time.

2 Powerlink can assist proponents with more detailed, project-specific capacity and congestion information as part of a connection enquiry. Powerlink encourages interested parties to contact Powerlink s Business Development team by phoning (+617) 3860 2111 during business hours, or by emailing Interested parties are also encouraged to refer to Powerlink s Transmission Annual Planning Report (TAPR), which provides information relevant to the development of new generation projects. The information presented in this document is current at 30 June 2017. Updated network capacity information may be published on Powerlink s website from time to time, and interested parties should check for this information. To join Powerlink s Non-network Engagement Stakeholder Register (NNESR) and be notified of any updates to this data, please email Calculation methodologyIndicative available generation connection capacity is outlined at 60 locations across Powerlink s transmission network.

3 Locations close to major urban areas are unlikely to host a large renewable energy project and are not part of this guide. In addition, substations operating at 275kV and 330kV are not part of this guide as connections at these voltages will generally accommodate generation levels in excess of 400MW. Analysis is based on the existing configuration of the transmission network with committed changes to the network applied. Possible (uncommitted) future network changes, including those outlined in chapters four and six of Powerlink s TAPR may alter the level of supportable calculation methodology assumes the technical standards that currently apply to transmission network design and power system operation.

4 Changes to these standards have the potential to change the network capacity available to fields are published for each connection point as described Supportable GenerationA connection point s thermal capacity relates to the highest level of generation that can be exported through aconnection point without exceeding the rating of a transmission circuit following the loss of a network element. This fieldis applicable to all forms of levels of thermally supportable generation reported in Table 2 are based on a single generation profile, as shownin Table 1. This generation profile includes a typical noon output for the committed renewable generation thermally supportable generation at a connection point may be substantially greater and/or lower with differentgeneration patterns and network configurations.

5 For example, under lower Far North Queensland and Ross generation,the available generating capacity at Strathmore 132kV is less than Capacity Guide30 June 20173 Table 1 Base summer noon generation dispatch assumption for available thermal capacity guideZone/InterconnectorGeneration/Flow (MW)Far North220 Ross311 North156 Central West2,458 Gladstone1,223 Wide Bay53 Surat14 4 Bulli1,756 South West1,705 Qld-NSW Interconnector Northerly flow (swing)300 Terranora Interconnector Southerly flow20 Each connection point s thermal capacity was calculated by iteratively applying increasing levels of generation to the connection point (balanced by changing power flows on the Queensland NSW Interconnector), and performing contingency analysis.

6 The thermal limit of a connection point was assessed as being reached when a rating breach was identified within the surrounding network. It may be possible for generation to be exported in excess of the thermally supportable generation if a fast generation run-back scheme is implemented by the generator to limit generation output following the relevant network contingency events. Strength Supportable GenerationA connection point s network strength capacity relates to the ability of power electronic connected systems to maintainstable operation. This network strength capacity limitation applies to only non- synchronous forms of generation,including most forms of solar and wind generation that connect to the grid through an inverter.

7 This parameter is not aconsideration for synchronous forms of generation, including thermal and Circuit Ratio (SCR) is a commonly used parameter for quantifying the power system s strength at a connectionpoint, and is calculated by dividing the short circuit power (in MVA) at a connection point by the installed level of powerelectronic connected generation (also in MVA). The SCR at the connection point strongly influences a plant s ability tooperate satisfactorily both in steady state and following a system the 2016 TAPR a SCR of five was used to determine the levels of generation a location could accommodate. Inconsultation with industry and equipment manufacturers, the SCR assumption has been reduced to two for the2017 TAPR.

8 This reduction in SCR is not a lowering of standards, but rather recognition of the advancing capabilitiesof generation technology, and seeking to represent the potential capacity which could be accommodated with suitablycapable equipment. It remains the case that generation must meet the National Electricity Rules (NER) GeneratorPerformance Standards, and generation proponents are required to demonstrate that their proposed generationtechnology is able to meet these standards during the connection change in assumed SCR underpins the increase in the available capacity indicated at some locations, compared to the2016 system strength supportable generation calculation uses the minimum post-contingent short circuit levels describedand listed in Appendix E of Powerlink s 2017 Connection of wind farms to weak AC networks , CIGRE WG , December Capacity Guide30 June 2017 Multiple independent power electronic connected systems in an area can interact with each other.

9 Any interaction between such systems, including non- synchronous generation and certain network infrastructure2, may reduce the effective system strength capacity available at that location. This effect has not been factored into the calculation of system strength supportable generation in Table 2, but will need to be investigated through modelling undertaken as part of the generator connection process. This is generally true of all connections, however it is anticipated to be especially relevant for the locations in Table 2 which are marked with a (1) as these locations host existing or committed power electronic connected system strength supportable generation at a location could be increased by measures which raise the local system strength, such as installing a synchronous condenser (SynCon).

10 Supportable GenerationNon- synchronous generation, including most forms of solar and wind generation, will be subject to the most-limiting ofthe thermally supportable generation and the system strength supportable generation. As such the lower of these twoparameters at each location is presented in Table 2 as the non- synchronous supportable generation. it is simply theminimum of the thermally supportable and system strength supportable generation supportable generationThe results of the application of the calculation methodology described above are presented below in Table 2. The non- synchronous supportable generation metric is also displayed geographically in Figure 1, and published on the AREMI spatial data platform3.