Western Australia is leading the way when it comes to replacing expensive networks with stand-alone systems that rely on solar and battery storage. EcoGeneration speaks to Western Power SPS project manager Margot Hammond about managing a mighty transition.

What are some of the peculiarities of the area you service? What are some obvious and not-so-obvious issues and difficulties about servicing your customer base?

The regional locations of our SPS customers can be a challenge given that face-to-face interaction is important at the start of the project.  Also, the geographical spread of our network, and the customers who might access SPS, brings different delivery challenges, such as inaccessible properties during winter in the South West region, with roads being swept away after heavy rainfall.

One of the not-so-obvious challenges is working around busy farming schedules. Whether it’s shearing, crutching, seeding or harvesting, there’s always a lot to do on a regional property and finding a suitable time to talk to our customers isn’t always easy.

Additionally, there will be a significant reduction in land access impacts for our customers through the removal of poles and wires in their paddocks. SPS unit footprints are also much smaller, at about 10 square metres.

What have you learned from the trial of stand-alone systems in 2016?

The key objective of our 2016 trial was to understand customer experience of an SPS. We wanted to measure customer satisfaction with SPS compared to the network, system performance and understand if the costs were comparable to network rebuild (see table). We expect future roll outs will benefit from efficiencies in procurement, customer engagement, technical enhancement and operation.

You’ve announced a major shift to stand-alone power systems elsewhere in the state. Are you using a standardised system design or is it not that simple?

We’ve worked very hard with WA businesses to refine the utility grade SPS solution we’re providing to our customers – it provides a network experience in relation to safety, with metro performance in relation to power quality and reliability. While we see our role as being pivotal in how far and fast the market grows, we want to keep the door open for innovation and refinement in future rollouts. We want flexibility while ensuring a certain level of standardisation so that our fleet design can be rolled out to thousands of our customers and still be maintained by our workforce in the years to come.

How do you size battery storage for these stand-alone systems? How many days can an average system provide power in overcast weather without resorting to diesel?

We design our systems to manage the peak load as well as ensuring flexibility. Some of our smaller systems don’t have a generator permanently attached but can have one added if required. Given the range of customer load requirements, we’ve designed our fleet to be modular and flexible, and able to be scaled up or down.

Generally, the most common system being installed is between 15-20kWh per day, and this would be a large working farm. Obviously, the nature, timing and duration of the load being used would impact how frequently the backup generation would be used. The design of the system is in accordance with the relevant Australian Standards, which incorporates a lifecycle assessment to identify the optimum mix of PV, storage and backup generator, generally allowing for up to two days of power without relying on the backup generator.

What is the maintenance regime for stand-alone power systems?

In the early stages of our deployment we used contractors to undertake the maintenance on a six-monthly schedule to align with manufacturer requirements for respective equipment warranties. We anticipate this will be optimised in the coming years, particularly with the adoption of new technology.

Can you describe the sophistication of the monitoring systems you plan to use?

Our monitoring system provides real time visibility of the units, enabling preventative maintenance such as topping up the diesel in an optimised run. It also provides asset performance data that can be analysed for trends, system performance, root cause analysis and security monitoring.

Do you have any plans to link stand-alone power systems into microgrids?

We do not plan to line SPS units in to microgrids; we see them as working independently of each other. SPS typically will provide a one-to-one connection, whereas a microgrid provides supply for a small town.

How did the Electricity Industry Amendment Bill 2019 pave the way for the rollout of stand-alone power systems in Western Australia?

The Bill is a significant milestone for the WA Government, Western Power and our customers.  It paves the way for regulation change that will allow us to transform our regional grid, providing us with a more efficient way to service our customers with safer and superior power quality. Our modelling identifies thousands of potential sites that can be transitioned to an SPS over the coming decades – the Bill makes this strategy a reality and we’re so excited to be part of the energy reform process that is taking place right now.

Are customers nervous about converting to solar and batteries? Are they scared about being “disconnected”?

The key message we’ve received from customers is how much they value their connection to Western Power and the service we provide – come rain, hail or shine they know we will be there, and we will still be there with SPS units. The concern isn’t about being disconnected; it’s about making sure the unit will provide what they need to run their day-to-day life. That’s why we spend time upfront to understand their energy needs.

How do you identify customers that would be better suited to SPS than connected to the network?

We look at the age, condition and location of the lines that are due for significant asset renewal. We assess the length of line, the number of customers located on the line and their load profile at a desktop level to work out the economic viability of the line. Then we begin the customer engagement to inform a more detailed economic assessment. As we are regulated and must demonstrate the most prudent option is progressed, it’s critical to ensure the project is economically viable. Customer participation is voluntary and a key part of the process.

What are your plans for distributed storage? What capacity do you expect the assets to be and how will you choose sites?

In addition to energy storage deployed for SPS and microgrids, Western Power sees many opportunities to deploy distributed storage in the network, with community storage trials conducted in urban areas serving multiple purposes.

Western Power and Synergy’s PowerBank trials provide a community battery that seeks to address network constraints (by providing services that defer infrastructure upgrades), paired with a retail offering that allows customers to “virtually” store excess electricity generated by their solar PV and draw on this in the evening. The use of a community battery takes advantage of cost efficiencies for larger battery systems, as well as avoiding installation costs and deterioration of battery performance, for customer-owned behind-the-meter storage solutions.

How will your plans for stand-alone systems be affected as large-scale solar takes hold in the state?

Western Power is excited to be a key part of the future of large-scale renewable energy in WA. Our grid will be the infrastructure that continues to allow connection and distribution of energy from large-scale solar and wind right to households and businesses for use.  We’re also thinking about how our future microgrids can make use of larger scale renewables. For example, our Kalbarri microgrid will be taking advantage of Synergy’s wind farm in Kalbarri, as well as local rooftop solar, allowing for a continuous electricity supply for longer.

In relation to SPS, even at our highest modelled rate of SPS adoption the impact on demand is small and we don’t expect it to have a significant impact on energy markets or the profitability of large-scale renewable projects.