A new ABB energy storage and grid stabilization solution is helping Australian transmission and distribution utility, AusNet Services, provide additional power during peak demand. John Theunissen of AusNet explains the whys and wherefores of the solution.
AusNet Services is the largest energy delivery service in Victoria, the second most populous state in Australia. The company supplies electricity and gas to more than 1.3 million homes and businesses, and employs around 2,200 people.
In 2014 AusNet Services selected ABB to supply a hybrid grid energy storage and diesel generation system for its electricity distribution network in the eastern part of the state. The 1 MW trial solution automatically provides additional power for the 22 kV network during peak demand. It can operate at full power for one hour and provide electricity for about 300 homes.
The turnkey solution comprises ABB’s Microgrid Plus distributed control system and PowerStore™ grid stabilization system. It includes a 3 MVA mobile substation and a backup diesel generator. The solution is portable and housed in outdoor containers for easy deployment. The battery is supplied by ABB’s partner in the project, Samsung SDI.
ABB was also responsible for power system modelling and grid connection compliance, design and testing, manufacture and assembly, installation and commissioning. ABB will also provide AusNet Services with support for the two-year duration of the trial.
The solution has been in operation since 1 December, 2014 – the start of the Australian summer.
Interview with John Theunissen, manager of network modernization at Aus-Net Services.
Why did you decide to initiate this project?
Energy storage is one of those technologies that is very much on the radar in our business. One of our objectives as a company is to embrace new technologies like this and to try to get as much value out of them as possible. We therefore applied for – and were awarded - incentive-related funding for the project from the regulator. Our purpose was to test the technology’s ability to enhance demand management during peak periods, as well as to deliver benefits in other applications like power factor correction, voltage imbalance and island operation.
Why is demand management so important?
An energy network is a real-time system in which supply and demand has to be managed on a moment-by-moment basis. You have to operate within the capacity tolerances of the assets in the network. If you don’t it might lead to asset failure and power supply problems for customers. But asset and network utilization is not uniform during the day or during the year. There might only be a few occasions a year when you exceed the capacity of your assets. So the question is: How can you efficiently manage demand during those periods when demand exceeds capacity? One answer is to ask your customers to reduce their load, which is not always practical or achievable. Another is to augment the network with equipment upgrades, but that is expensive and time consuming. A third is to use innovative non-network technologies like this one.
What are the advantages of the technology?
One advantage is that the solution doesn’t affect our customers at all. We don’t have to ask them to reduce their load during the peak demand season. But the real beauty of the solution is that it is energy-dynamic – we use it to match the peaks and troughs in demand. We use the power stored in the battery during the peaks when demand is high, and recharge the battery during the troughs when demand is low.
Why did you select ABB for this project?
We wanted to partner with an organization with experience and a track record in this technology - a company with an international footprint but also with local presence and a local engineering capability. Before we initiated the selection process we looked at some of the reference sites and ABB was one of the companies that stood out in this technology. Secondly, we wanted a partner with the ability to do this project on a turnkey basis. This is a new technology so minimizing our exposure to risk is an important issue for us.
What uses do you expect from this solution?
We see a great future for energy storage. One of the key benefits is that it offers multiple value streams. If you want to get the most out of a solution like this then you have to be able to get as much value out of it as possible. For example, the main application for us is peak load management. But we also want to test how the solution can help improve power quality in environments where voltage stability is an issue, such as residential areas with many roof-top PV installations. Another use we want to test is islanding – creating a mini-grid in a section of the network where we have maintenance work to do. Normally, we would have to cut the power off for customers in that section, but by creating a mini-grid we can keep them supplied with power while we are doing maintenance.