The news continues to be dominated by new renewable projects signing Power Purchase Agreements and the Integrated System Plan that is forecasting 28GW of new capacity is required by 2040. So if we are already seeing average curtailments for renewable projects of 5% across the National Electricity Market (NEM) in FY20 then how are we going to manage the integration of new projects?
Discussion continues to increase regarding the impacts of curtailment on the grid and how these are starting to affect the viability of projects when combined with declining loss factors and increasing FCAS causer pays costs. These curtailments can arise for a number of reasons including thermal issues and system strength requirements.
Figure 1 shows the hotspots for the locations in the NEM where the most MWhs of curtailment have occurred in FY20. Due to the large number of installed MWs from wind farms in Western VIC this area leads the way as having the highest density of total MWhs curtailed. This area includes, Murra Warra, Yendon and MacArthur (both Yendon and Murra Warra wind farms were curtailed by more than 15%). We also see a large amount of curtailment occurring in SA, this is mainly from the Lake Bonney, North Brown Hill, Willogoleche, Snowtown, Hallett and Wind Farms. Except for Lake Bonney all of these wind farms are located north of Adelaide which results in a significant amount of generation curtailed in that region (all of these wind farms are also curtailed at around double the NEM wide curtailment rate ~10%). We are also begining to see a emerging curtailment issue in Northern QLD, primarily from Emerald, Daydream and Whitsunday solar farms as well as Mount Emerald wind farm (both Emerald and Whitsunday solar farms are well above 10% curtailment). We would also expect this trend to continue that given the system strength issues in Northern QLD and the recently confirmed 27 constraint equations released by AEMO have the potential to curtail ~1GW of renewable resources.
This graph doesn’t show the curtailment from the 4 solar farms (other than Broken Hill) that were curtailed in the North West Murray region; Karadoc, Wemen, Bannerton and Gannawarra solar farms. Which would have increased total MWh curtailment in the NEM by around 15% in FY20.
While the ISP provides us a way forward to deliver interconnection between regions, what we can see from this map is that there is a considerable amount of curtailment developing within states that is unlikely to be alleviated through the currently identified ISP projects (except perhaps VNI West which should assist with the north west Murray region). There is a significant role for the TNSPs to develop their own solutions for network constraints which were are beginning to see as Powerlink procures more system strength in Northern Queensland through an innovative arrangement with Neoen.