Microgrids are defined as a collection of electricity producers and consumers (typically households and small businesses) who buy and sell electicity between each other. An important characterisitc of this group is the ability to isolate themselves from the grid during times of emergency and still function, based on their combioned production and consumption of electricity. Some proponents of microgrids contend that special control equipment is required at each property in order to control the operation of the micrograd. On the other hand, others contend that a microgrid can exist without such equipment, with the sharing between participants worked out in arrears (one day after the production and consumption), based on the half-hourly imports and exports of electricity as recorded by their smart meters. Such a microgrid is often called a Virtual MicroGrid (VMG).

In 2022, The Taggerty Group (in conjunction with the Murrindindi Climate Network), conducted a Feasibility Study for a Virtual MicroGrid in Marysville. The study considered the feasibility of an islandable Microgrid for the town of Marysville in two stages. Stage 1 of the project looked at the electricity purchase and sale records of a sample of 13 residents via their NMI data obtained from Ausnet Services. Using a matching procedure similar to the Powertracer system developed by Enosi Australia, the examination showed that power sharing was possible, and demonstrated the important role that non-solar properties could play in such a Microgrid. Importantly the electricity network configuration for Marysville within the overall elecricity grid (end of the line) is conducive to creation of an islandable MicroGrid.

However, to be islandable, the township must be able to produce and deploy sufIicient electricity within its own boundaries such that it can become effectively independent from the Main Electricity Grid. For this reason, Stage 2 of the project examined augmentation of the power generation ability of the residents by the inclusion of a Solar Farm and Battery in the town’s power generation capabilities.

It was shown that it would be possible to achieve Grid independence by the installation of a suitably sized solar array and battery. However, the question remained as to whether the cost of such an installation was justiIied by the outcomes.

As in many studies, every answer found raises more questions, and this study was no different. Within the time and budget constraints of the study, not all questions could be addressed. Among the most important questions still be be addressed are:

• What are the economic costs and beneIits of such a proposal?

• What are situations which would most demand islanding of the MicroGrid?

• What is the value of a reduction in power outages to residents and businesses in Marysville?

• Are there alternative ways of achieving the objectives of an islanded Microgrid?

• Should electricity trading within a MicroGrid be encouraged by special tariffs which provide MicroGrid buyers and sellers with better prices than when trading with the Grid?

• What are the technical issues that need to be resolved when establishing an islandable Microgrid?

Virtual MicroGrid at Marysville