This document is the final Knowledge Sharing Report for SA Power Networks’ Advanced VPP Grid Integration Project. This report describes the project, the activities undertaken, outcomes achieved and key lessons learned.
Report extract
Virtual Power Plants (VPPs) that aggregate many customers’ individual Distributed Energy Resources (DER) such as batteries and solar under market-aware control strategies have great potential as part of Australia’s future energy mix. VPPs enable new value streams for individual customers and, having the ability to respond rapidly to inject or sink large amounts of power, can potentially play a key role in balancing an energy system dominated by intermittent renewables. VPPs also, however, present particular challenges in grid integration because the physical capacity of the local distribution network, in particular the low voltage (LV) network, to accommodate the energy exported during VPP operation is limited at certain times.
To protect the integrity of the network for all customers, distribution network operators typically set static export limits at each connection point, currently 5kW for most small customers in South Australia. These limits must be set at a level that ensures that energy exports do not cause local failures in the worst-case conditions, including when multiple batteries in a VPP are dispatched to export at a time when the network is already heavily loaded. Modelling conducted in 2018 by SA Power Networks suggested that these limits would likely need to be reduced in many areas to protect the network if there is widespread enrolment of household DER in VPPs.