In remote communities, ensuring reliability can be one of the greatest challenges facing a network operator. Western Power has recently discovered the power a Battery Energy Storage System can provide if the network is ever disconnected; and in the process of connecting their system to the grid, effectively written the book on utility-scale battery integration into the grid.
The town of Perenjori, which sits between Perth and Geraldton in Western Australia, has a reliability story familiar to other regional centers spread out over the vastness of Australia.
Serviced by a single 75km long feeder line from Three Springs, the town’s power supply is subject to the elements – which in these parts of the west are unpredictable and volatile.
Anyone living in the town prior to 2016 would have said unplanned power outages were a fact of life. Back then, Perenjori averaged around eleven outages a year, totaling nearly 30 hours.
Western Power Project Manager Ian Anderson said this customer experience was unacceptable for homes and businesses in the community, and a source of frustration for crews on the ground and engineers searching for solutions.
“The stark reality was that our approach to improve the reliability through traditional maintenance and investment was not returning the improved reliability performance we wanted for homes and businesses in Perenjori,” Mr Anderson said.
“When you get those long single lines like the one running to Perenjori, many different things can cause an issue, from falling tree branches through to a more serious fault,” he said.
“Although 90 per cent of the time it would be something simple, it takes time for a crew to patrol the line, find and remedy the issue – sometimes a few hours. During that time, the town has no power.”
So Western Power – in a world-first – installed a large community Battery Energy Storage System (BESS) for the town that could instantaneously provide up to four hours of power if the line went down.
On first glance the concept was simple but, as with all technology trials, the devil was in the detail and as this was the first attempt at a BESS integration into an existing network, the details didn’t really exist.
Mr Anderson said that while the base technologies (lithium ion batteries, industrial inverter/charger systems) were well proven and relatively low risk, the way they operated together and with the network interfacing control systems was new and unproven.
“Battery storage systems are generally not set up at the end of long line; rather, functioning either continuously connected to the power network, or as a backup after power has been lost,” he said.
“And this system, which is always online, operates fully autonomously to monitor the state of the network, detects faults back into the HV backbone and can instantaneously disconnect from the grid – all while supporting the town of Perenjori with no power interruptions – had never done before.
“As there was little directly relevant knowledge anywhere to draw on, we had to decide on operational parameters by design, intuition and sometimes on best guess.
“In effect, we have written the book on how to integrate utility-scale batteries into the grid. The benefits have far outweighed the struggles, the swearing and the long hours of problem solving.
“Given most of the time Perenjori only lost power for a couple of hours, the battery will hopefully tide them over while the fix was happening and reduce the amount of time without power during more serious faults.
“An automated SMS notification system also provides warning to the community of impending outages,” said Mr Anderson.
BESS was installed on the outskirts of town in 2018 and is normally connected in standby mode and kept charged by the main network.
“As it was the first time anyone had installed anything like this in Australia, we learnt a lot through the installation process. It took us longer to integrate the battery into the network than we expected, but we have persevered and it’s now working really well.”
The town’s residents have been an important part of the process, embracing their role as trial participants and feeding back to the project team to help find and rectify issues.
Mr Anderson said there was an enormous sense of achievement from the team in conquering the seemingly never-ending stream of technical challenges the BESS project presented. Importantly, these successes have translated into improvements for the families in Perenjori and their energy lifestyles.
“The community has said that being able to finish cooking meals, not losing unsaved documents on computers, and even the tiny things like not resetting digital clocks nearly a dozen times a year are the customer experiences that matter.
“One of the big successes has been the SMS message the Perenjori residents receive when the line goes down, letting them know that BESS has kicked in and is supplying them with power they otherwise wouldn’t have had. It also lets them know if BESS is running low on power, so they can prepare for a potential outage rather than be caught off guard.”
“Removing the suddenness of an unplanned outage from the customer’s life has given them back the power to make choices and plan better. These things rarely show up on blueprints but are often the outcomes that really matter.”
Results from 2019 suggest BESS is really paying off, with Perenjori avoiding over 25 hours of outages in the first 18 months of operation.
“We have had less issues on the feeder line this year, so typically the number of outages would be higher. But either way BESS has covered most of the ones that have happened, so the town only had just over five hours total of power outages last year.
“Although BESS was expected to have a minimum of two-hour charge, it has exceeded expectations, powering the town for longer stretches of four to five hours.
“BESS also helped us during planned maintenance works, supplying power to the town. That meant we’ve been able to do upgrades to the line without impacting homes or businesses in the Perenjori township at all.
“Now we’ve tested and shown how well this kind of community battery unit can work for end of the line locations, we can look to other places where this might work as part of our modular and autonomous network,” Mr Anderson said.
“It feels great to have some real solutions for our rural customers.”