This APVA report presents the results of a case study undertaken into technical issues posed by growing PV penetrations in the distribution networks of Magnetic Island and the adjacent city of Townsville in North Queensland, Australia, and their management by the local network utility, Ergon Energy.
High and growing penetrations of mainly small, distributed PV systems exist within Ergon Energy’s distribution network. Magnetic Island is one such example of high PV penetration with peak PV penetration (PV generation contribution to meeting load) of 34% for the whole island during September 2012. The majority of the PV systems on Magnetic Island are small scale (< 10 kW) residential systems, with several larger systems of up to 22 kW and one 100 kW system at the public Solar Skate Park. Magnetic Island and Townsville Solar City provide a particularly useful case study as there has been extensive metering of the PV systems installed under the Solar Cities program; a number of trials have been conducted relevant to managing high penetrations of PV, some of which are described in this case study; and Townsville has hosted a number of high profile PV systems.
While the PV output does not coincide with peak loads on Magnetic Island (driven by residential air-conditioning on summer evenings) PV does contribute to overall reduced loading on the network and, importantly, deloads the network during daylight hours on these peak days, that tend to be very sunny. To date, some voltage issues have arisen in high impedance sections of the network but these have been successfully resolved through network balancing, adjustment and minor augmentation. Despite some concerns about the potential for PV system islanding, no instances have yet been recorded. Minor reverse power flow has not caused any network operation problems, while inverters have not produced significant harmonics nor caused power factor issues.
This case study, prepared by UNSW with the active involvement of Ergon Energy and funded by ASI and ARENA, is the third in a series of case studies aimed to give Australian and international audiences insight into some of the key technical challenges and management options to facilitate high PV penetrations in Australian electricity networks. These case studies are being undertaken as a part of a broader ARENA supported research project entitled “Support for Australian participation in an international RD&D collaboration on Photovoltaics – IEA PVPS Task 14: High penetration of photovoltaic systems in electricity grids”.
A key objective of this research project is to facilitate the integration of higher PV penetrations in Australia and internationally. To coincide with an international Task 14 meeting in Australia, a high PV penetration workshop with local and international speakers will be held in Sydney on Tuesday 26 November 2013. Please contact firstname.lastname@example.org for further details.