Electrical Vehicles (EVs) are coming to Australia with five new mainstream models launched in 2018/19. One clear barrier to adoption is that a significant number of Australian households do not have enough capacity within their electricity distribution board to charge multiple cars simultaneously. However, Australia has some of the highest penetration of roof top solar photovoltaic (PV), the technology used to convert sunlight into direct current electricity, in the world. This leads to the frustrating situation for EV owners where excess renewable energy is exported to the grid but then at other times there is insufficient power to charge their vehicles. Home battery storage systems offer a partial solution as they can store some of the excess solar PV but cannot be relied on to always provide the extra power needed to charge a vehicle once depleted.
Delta Electronics (Australia), based in Clayton Victoria, is part of the Delta Group – the world’s largest power electronics supplier. It specialises in renewable energy systems and EV charging solutions, carrying out systems design and localisation to meet Australian requirements. Delta’s Senior Manager for E-Mobility and Energy Storage, Matti Dinkelmeyer, approached CSIRO Energy's Centre for Hybrid Energy Systems (CHES) to help develop a better solution.
The concept was to combine domestic single-phase electricity supply with the output of a home storage battery charged by solar PV panels to allow fast charging without the need to upgrade the electricity supply. However, this introduces complex energy management problems due to the differing availability and supply characteristics of grid, battery and PV derived electrical power.
CSIRO's SME Connect was able to assist by facilitating an Innovation Connections grant to support an initial project to design, build and test a prototype fast charging system. The project was carried out by CSIRO Project Leader and CHES Director, Christopher Munnings, and resulted in a successful demonstration of the prototype charging a Nissan Leaf EV.
The next step was to refine the design and improve the thermal management of the system. A complete demonstration unit could then be built for thorough evaluation. A second Innovation Connections grant was approved for the second stage, which allowed the development of a control system to allow up to 4 cars to connect to the single inverter and battery. Delta was also able to apply for an Innovation Connections Graduate Employment Grant assisting them to hire a recent graduate to add additional resources to the project. Six months later the demonstration unit was in operation.
Delta is now commercialising the EV charger, which will become part of its standard product range. As part of this activity, CSIRO is carrying out a $1 million project with the Victorian Government, Nissan and Delta involving field trials of the system developed through the Innovation Connections projects.