I recently visited the “PowerBank” community battery energy storage trial in the sprawling residential suburbs of Meadow Springs and Port Kennedy in Perth, Western Australia. Both of these suburbs are ranked in the top 30 suburbs in Western Australia for rooftop solar uptake [1].
WA has embraced Distributed Energy Resources (DER) with one in three households in the South West Integrated System now generating their own renewable power with photovoltaic (PV) solar panels and growing at around 2,000 households a month.
These suburbs have experienced continued growth and is peak demand is encroaching on network capacity limits. To date, capacity constraints have been mitigated through load transfers between distribution substations [2]. Despite the high penetration of PV, the distributed generation contributes minimal demand reduction at time of substation peak load in the early evening (i.e. the “duck curve” 🦆). The 2021 forecast distribution network capacity of the region is shown below [3].
Technological developments in energy storage provide a new utility-grade solution to manage the power distribution and flatten the load profile (i.e. 🦆🔨):
- Peak Shaving: Discharge at times of peak demand to avoid or reduce demand.
- Load Shifting: Shift energy consumption from one point in time to another.
- Demand Response: Discharge instantly in response to signals from a demand response aggregator to alleviate peaks in system load.
- Emergency Backup: Provide intermediate backup power in the event of a supply interruption.
Community energy storage deployment has been green-lighted in WA with the Electricity Industry Amendment Bill 2019 [4] and the release of the Distributed Energy Resources Roadmap [5] in April 2020. The DER Roadmap recommends to install community batteries in locations that are most in need of power balancing.
The PowerBank community battery is an Australian-first trial to integrate bulk solar battery storage into the existing grid that also provides customers with a retail storage option [6].
The local customers don’t have to purchase a behind-the-meter battery, as the local Distribution utility, owns and operates a Tesla branded PowerPack standing proudly in the local park and is featured on their recent advertising campaigns.
Tesla’s PowerPack is commercially available modular battery bank for utility and business energy storage. Each 232 kWh Powerpack is a DC energy storage device containing 16 individual battery pods, a thermal control system and sensors to monitor and report on cell level performance [7].
The PowerBank trial has installed two modules (@ 232 kWh each) and is able to virtually store up to 8 kWh a day of excess generation for 50 trial subscribers (approx 464 / 8).
Although I anticipate this trial will not be operated islanded from the power network, assuming each customers consumption is 2 kWh, these 50 subscribers could potentially ride through an outage up to 5 hours (approx. 464 / 50 / 2).
Standing next to the install there was limited buzzing noise, but as a large white box within a community park, one flagship site has already been a target for vandals 😕.
I’ve been unable to source budgets or project costs for the trial. The Telsla PowerPack costs in the region of USD $172k for a 232 kWh unit [8]. The installation also requires foundations, trenching, low voltage cabling, terminations, protection or fusing, and… reconfiguration of the park’s irrigation system plus graffiti cleanup. I’d anticipate a commissioned site to manage the load profile of 50 customers may cost up to AUD 500k.
Tesla provide a 15-year “no defect” and “energy retention” warranty for the Powerpack. Tesla guarantee that the energy capacity will be at least a percentage (within a range up to 80%) of its nameplate capacity during specified time periods, depending on the product, battery pack size and/or region of installation, subject to use restrictions or kWh throughput caps. Tesla also offer extended warranties, such as 10 or 20 year performance guarantees [9].
The PowerPack utilizes the Tesla’s Microgrid Control System application available across their product range. The application provides a range of alarms and system status parameters required to operate the energy storage system with a shiny user interface [10].
Although it appears limited in Real-Time information for asset management of the battery cells such as cell degradation and capacity. IT/OT convergence is coming for power electronics! In that, rather than the use of an infrastructure asset management framework (such as ISO 55000) and internal operations, the mindset shifts to managing service and performance through warranty and support agreements.
Once (“partnered”) within the Tesla ecosystem, the Microgrid application can be scaled to other energy use cases such as distributed generation and electric vehicles.
The PowerPack provides an Ethernet port for access to Modbus TCP/IP and DNP3 protocols and Rest API [12]. This would provide interface to Tesla’s application or the Distribution utilities Distribution Management System or Distribution Energy Resource Management System (DERMS).
There was no visible antenna mounting to provide strong connectivity. I presume there is a 4G modem providing remote SCADA (and configuration access, firmware updates etc) within the kiosk. The connectivity will be valuable as it also appears there was no SCADA connectivity on the upstream transformer, distribution frame or ring main unit. At both sites there was 2 bars (-113 dBm) of 4G signal using the commercial Telstra mobile network.
If and when the community storage is deployed at scale, and under all operating conditions (incl. black start), combined with electric vehicle charging stations and distribution market operator (or virtual power plant) use cases, the control systems and telecommunications requirements are required to also scale.
Energy storage provides a new solution to manage the load profile where customers are both consuming (demand) and generating (supply). The application of energy storage technology such as a community storage on the low voltage distribution network is helpful to evaluate the solution to reduce energy costs and carbon footprint. This trial will inform technical and economical evaluations, and also facilitate regulatory, governance and operational integration.
References:
[1] https://westernpower.com.au/community/news-opinion/who-really-is-number-1-for-pv-in-perth/
[5] https://www.wa.gov.au/government/distributed-energy-resources-roadmap
[7] https://www.tesla.com/en_AU/powerpack
[8] https://electrek.co/2020/03/31/tesla-powerpack-price-commercial-solar/
[9] https://ir.tesla.com/node/20456/html
[10] https://www.gemenergy.com.au/wp-content/uploads/2017/11/Powerpack_Microgrid-System-Brochure.pdf