This Lessons Learnt Report discusses initial technology choices, customer onboarding into the trials, and infrastructure deployment for the Horizon Power Carnarvon trial.
Report extract
1. Introduction
Horizon Power is conducting a series of technology trials in the town of Carnarvon in the Gascoyne – Mid West region of Western Australia (WA), to explore economically efficient options for microgrid operation. The trials are exploring the management of high penetration levels of Distributed Energy Resources (DER), cloud-based aggregation of DER into Virtual Power Plants, advanced data analytics, and digital apps that provide customers with data with which they can make informed decisions.
Carnarvon, situated on the mouth of the Gascoyne River 900 km north of Perth, has a population of approx. 5,500. Horizon Power commissioned a new 13 MW gas-fired (with diesel peaking) Mungallah Power Station in 2014. Ownership of the power station offers the trials control system access, integration and optimisation options that would not be possible with an independent power producer operating under a power purchase agreement.
With an economic base of predominantly primary producers, Carnarvon experienced rapid uptake of solar photovoltaic (PV) systems in 2008 – 2011 with higher than average system sizes, typically 10-30 kW, used to offset cold storage and water pumping power purchases.
The distribution system has a high feeder and transformer loading of solar PV and requires sufficient spinning reserve to cover the variability in renewable energy generation caused by coastal weather patterns. Carnarvon was the first regional WA town to start pushing the boundaries of Horizon Power’s solar PV hosting capacity in 2011. The town’s population has always held great enthusiasm for solar PV with 121 customer connected systems as well as two commercial solar farms operated by Solex (45 kW), which was the first privately owned commercial solar farm in Australia, and EMC (300 kW).
The Carnarvon DER trials which commenced in late 2017, and include a team of researchers from the Engineering and Energy Discipline at Murdoch University, aim to resolve the technical, operational and transitional barriers to a high penetration DER business future. By conducting a series of technology trials and experiments over three years involving the monitoring and control of solar PV and energy storage, the technology trials aim to answer questions such as: Have we thoroughly explored the operational risks associated with a DER control system? Can we employ controls to manage DER in a microgrid to support Horizon Power’s high penetration DER future assumptions?
Can such a DER management solution monitor and control energy storage to reduce peak demand or peak export? Moreover, can the use of such a control solution be used to increase DER hosting capacity and penetration of renewable energy into the network?
The project has engaged 82 residents and businesses with solar PV systems as participants in the data acquisition phase of the trials. Each participant was gifted a Solar Analytics solar smart monitor (rebadged Wattwatcher) to separately meter their solar PV system production and network load every five seconds.
The second phase of the trials, completed in March 2019, saw the installation of new combined solar PV and battery systems at the houses of an additional ten participants. Six of the existing data participants also received a battery and inverter to augment their legacy PV systems, and the Solex commercial solar farm received an inverter upgrade to a portion of its array.
These seventeen participants received a ‘Reposit Box’ DER controller allowing Horizon Power to monitor and control their DER systems through aggregation into a VPP established in the Reposit cloud platform.
We have concentrated the majority of the new DER and system upgrades onto a single feeder with an existing moderately high penetration of solar PV. The solar PV production on the Gibson Street low voltage feeder regularly exceeds the combined average load on the feeder at midday, exporting its excess energy into the wider Carnarvon medium voltage network. By installing additional DER, we have created a high penetration DER environment, to test DER control techniques on a live network with real customers and variable weather.
Throughout the trials, we are conducting a series of experiments using customer’s DER systems to investigate the network impact of solar PV generation and behind the meter (BtM) systems, confirming the viability of high penetration DER in Horizon Power’s microgrid networks.
This report covers initial technology choices, customer onboarding into the trials and infrastructure deployment. A lessons learnt report at the end of the project in 2020 will cover technology performance and R&D objectives in greater detail.