Advanced planning of PV-Rich Distribution Networks
Over the last twenty or so years, residential solar PV has grown from a technology loved by a few early adopters to one that is embraced by many Australians. Whilst this extraordinary growth has brought significant environmental and economic benefits, challenges associated with the integration of residential solar PV into local electricity distribution networks have also become more significant.
Indeed, determining the limit on how much more solar PV we can put on our roofs without compromising power system operation is a technically complex problem.
With support from the Australian Renewable Energy Agency (ARENA), the Melbourne Energy Institute and AusNet Services have been examining this solar PV ‘hosting capacity’ problem. The team, led by Professor Nando Ochoa of the University’s Department of Electrical and Electronic Engineering, have first developed high fidelity distribution network models to assess residential solar PV hosting capacity by using large amounts of measured network and customer data.
The latest report on their ARENA project, Advanced Planning of PV-Rich Distribution Networks, focuses on more traditional approaches to raising solar PV hosting capacity and the so-called Volt-Watt and Volt-var settings that were mandated in Victoria in late 2019.
This report finds that the new Volt-Watt and Volt-var settings can have significant benefits for both customers and the network. Voltage issues and the resulting curtailment of solar PV can be reduced, enabling at least 20% of residences within the same network to have solar PV. When complemented by traditional approaches to increasing hosting capacity, including careful setting of existing network assets or targeted network augmentation where required, the solar PV hosting capacity can be raised to about 40%. Significantly higher hosting capacities may even be possible if certain technical requirements are relaxed; something that we should be able to evaluate as residential solar PV continues to grow.
Current research by the MEI /AusNet team is now focused on non-traditional approaches that promise even higher hosting capacities. The use of more advanced and controllable solar PV inverters, voltage regulation devices and battery energy storage systems will all be examined.
“This partnership with AusNet and ARENA is already delivering important findings”, said Professor Michael Brear, Director of MEI.
“Almost 25% of Australian homes already have solar PV, and this study has shown that this is starting to exceed the hosting capacity of networks that weren’t designed for solar. However, the good news is that careful management of these networks, coupled with targeted investment where required, should achieve much higher hosting capacities.”
“Professor Ochoa’s ongoing research with AusNet is now exploring means by which consumers can realise even greater economic benefits from smarter solar and complementary technologies, whilst we all then benefit from lower greenhouse gas emissions and enhanced network operation.”