Victorian network company Powercor says it has found an innovative way to squeeze more wind and solar farms onto its grid without having to install additional poles and wires or upgrade its equipment – and without having to heavily curtail new renewables projects.
The major cost and time-saving breakthrough, which Powercor believes to be a world first for a distribution network, is called the High Voltage Distributed Energy Resource Management System, or HV-DERMS.
Essentially, HV-Derms promises to allow more large-scale renewable generators to connect to the grid, while also maximising the use of the same network infrastructure, maximising reliable renewables output, and minimising additional costs to developers and, ultimately, consumers.
Developed by Powercor’s engineering team alongside industry partners, HV-Derms works as a sort of traffic control system, providing real time operating limits to dynamically adjust the energy output of generators depending on network conditions.
The result is more “flexible exports” from wind and solar farms, which is great news for developers, who will now be able to gain grid access in parts of Victoria based on the dynamic capacity of the network, rather than its worst-case capability.
This is significant, considering Victoria has been one of the National Electricity Market states hardest hit by constraints to wind and solar generation output because of grid congestion across its networks.
The Powercor network spans a region representing more than 60% of Victoria, including some parts of the troubled West Murray Zone, which has some of the best wind and solar resources in the state but limited grid capacity – and a queue of projects waiting to connect.
“This system will reduce the need for new renewable projects to have to spend millions of dollars to upgrade parts of the network that might only be limited for short periods in a year,” said Powercor’s head of network planning, Andrew Dinning.
“The system allows us to more easily and reliably control generation at all hours of the day to maximise both export and reliability if, for example, extreme weather conditions impact the network or we need to undertake critical maintenance.
“We believe this is the first time a distribution network has adopted this level of real time dynamic control for large scale renewables,” Dinning said.
Powercor says the HV-Derms should also reduce down-time for existing generators, helping to minimise disruption from outages or routine maintenance, while at the same time giving the utility new and better ways to control output levels or network disturbances.
The system, which came into play on Powercor’s grid in March, now includes 36 existing wind and solar generators totalling 1.07GW of capacity in the system.
All new generator connections will be facilitated under HV-Derms, the company says, giving them the ability to opt for a dynamic export limit to avoid infrastructure upgrades and reduce costs.
“The time and the cost and effort involved in upgrading networks, new substation builds, overhead line restringing; it’s a lot of cost … [that is] is pushed onto the customer at the end of the day,” said Neil Bell, the power assets manager at Epic Energy, which manages wind farms and worked with Powercor to integrate HV-Derms.
“By not having to do that we can generate green electricity cheaper and therefore given it cheaper again to the final households,” he said.