Q&A with Jey Shivakumar: How microgrids can serve residential and industrial sites

In this interview, Jey Shivakumar, Principal Engineer, Energy Transformation Services, Cossill & Webley, discusses two of the case studies he presented in his recent talk on decarbonisation through the use of microgrids at Energy Next 2023. The sites were Witchcliffe Ecovillage and Peel Business Park — both located in WA.

Witchcliffe Ecovillage

Witchcliffe Ecovillage is a picturesque sustainable community of 11 residential clusters each containing 20–25 homes. The community produces and harvests its own energy, water and fresh food produce onsite.

Image courtesy of Witchcliffe Ecovillage.

Could you describe the Witchcliffe Ecovillage site and what was involved in designing suitable energy infrastructure for it?

This development is located 8 km south of Margaret River, in sub-regional WA. The electrical network within the area is constrained with long feeders that are a mixture of pole-top and underground cables. Any system designed to interface with this type of network would need to consider reduced network reliability (dropouts) and limited hosting capacity for large-scale embedded generation systems.

Are you able to go into some of the manufacturers that were used and the reasons for using them?

The suppliers for the core embedded generation systems were Solarwatt (panels), Fronius (Inverters) and Tesla (Battery System). All these products were chosen by the developer since all of these suppliers were willing to engage early, assist with early procurement and offer bulk purchasing.

We wanted to achieve as much consistency in the installed systems as possible to limit compatibility issues and have strategic spares available for potential replacements.

Image courtesy of Witchcliffe Ecovillage.

How many people worked on the installation, approximately?

The project management, design and installation teams comprised over 25 people with various skill and experience levels coming together.

Did you encounter any challenges?

The biggest challenge was the process of obtaining all the relevant approvals. As the project was pushing the envelope in terms of sustainability goals, approval authorities did not have processes to handle what we had proposed.

A fair amount of time was spent consulting and engaging with all approval bodies to assist them in understanding our objectives, which eventually resulted in very positive discussions and opportunities to upgrade processes for future developments.

Could you talk about the advantages of energy sharing that were provided by this particular microgrid model?

As each cluster is, in effect, a private network microgrid, it has a single CT (current transformer) metered point of connection with a retailer and private metering within. All excess solar PV generation is shared among the residents within the cluster. Excess energy is then stored in the battery to be shared during the evenings, with any surplus above that to be exported to the grid and greater network.

Private metering within the site allows for any excess energy generated by individual residents to be shared among each other without having to go through a retailer. This also opens the door to allow variable pricing of energy for energy trading.

Peel Business Park

Peel Business Park, part of the WA Government’s multimillion-dollar Transform Peel project, is an industrial estate 70 km south of Perth designed for a multitude of uses, including manufacturing and fabrication; transport and logistics; wholesale storage; warehousing; and agri-innovation.

Peel Business Park Microgrid. Image courtesy of DevelopmentWA.

How did this large-scale project, which I understand is the first of its kind in WA, differ from Witchcliffe Ecovillage?

Witchcliffe is comprised of small private strata clusters with small distributed microgrids, each with a network/utility connection per cluster. Peel Business Park, on the other hand, is a large-scale single microgrid with a private network operator having a distribution network licence that owns and operates the network. The private networks within Witchcliffe are owned and operated by each individual strata cluster through the strata body.

Did this model break new ground? If so, what was particularly innovative?

The most groundbreaking element of this estate was the engagement of a private network operator instead of the standard state utility to service the lots with power.

Why was the decision made to use a microgrid?

The real push was to achieve an industrial estate that moves towards net zero, provides a reduced energy price for future tenants within the development and reduces the costs associated with network upgrades to service the site with power.

Do you think this set-up will become more widespread on similar industrial estates?

I believe that as time goes on and connecting to standard utility networks becomes more complicated, private operators will take over. Private network operators with smaller, more manageable networks will roll out and tie in with the greater grids.

This will allow private network operators to embed more sustainable systems/controls within these networks and, at the point of connection, provide network utilities grid services to assist with network stability.

Top image caption: Northern view of a Witchcliffe Ecovillage home. Image courtesy of Witchcliffe Ecovillage.