Made in the shade: Solar + storage = two EVs in leafy suburbs of Melbourne

A rooftop solar and battery storage system installed at a house in the leafy Victorian suburb of Blackburn – and which overcame problems of shading and complex roof angles to produce and store enough solar energy to power two electric vehicles – has been nominated as a finalist for a Clean Energy Council award.
The 13.5kW array, made up of Yingli solar panels combined with Sonnetschein lithium-ion batteries, was designed with household’s two pure plug-in EVs in mind: a Tesla Model S and a Nissan Leaf.
As well as generating enough electricity to recharge these two cars, the system – which was designed and installed by EnviroGroup – will reduce the Blackburn household’s dependence on the grid, despite a less than ideal roof space, and problems with shading – as you can see in the image below.

To overcome this issue, the system was optimised for terrestrial light, allowing the panels to produce high energy yields in low direct sunlight conditions. The solar panels were also combined with Enphase microinverters to suit the home’s various roof angles.
According to EnviroGroup’s website, the battery storage system faced its own design challenges:
Firstly, one of the electric car chargers could draw significant amounts of electricity very quickly; a problem requiring special high performance lithium batteries, for fast discharging and long battery life.
“Secondly the battery inverters also had to withstand these high currents and over 3 separate phases;” a problem requiring battery technology with high load capacities and a reputation for reliability.
The result is a system that ranked as a finalist for a Battery Back-up Award at the 2015 Clean Energy Council Solar Design and Installation Awards, presented in Melbourne. You can see all of the battery and solar system specs here.
Karl Edmondson, manager of solar battery design and consulting at EnviroGroup said the Blackburn project highlighted the growing number of customers wanting to use solar power, batteries and electric car charging to reduce their living expenses, and their impact on the environment.