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Battery Unit

In Australia more than 1.4 million households have rooftop solar panels, with double digit growth every year. In Perth one in five homes have solar power. Combined they equate to the biggest source of power generation in the state. The problem is solar power is only available when the sun is shining. At night time households are still completely reliant on the grid – often from fossil fuel sourced power such as coal and gas.

At Josh’s House for example, the existing 3kW solar panel system that was installed when the house was built produces nearly double the electricity used over the year, making the house comfortably ‘net zero energy’. Despite this, monitoring undertaken over the past 12 months has shown that over half of the power consumed (56%) is still being sourced from the grid. Solar energy storage using new generation lithium iron phosphate (LiFePO4) batteries is emerging as a potential solution to this vexing issue.

As part of the ongoing research activities at Josh’s House through Curtin University and the CRC for Low Carbon Living, a new 8kWh LiFePO4 battery unit has been installed at the house with the aim of testing just how effective solar energy storage can be in reducing grid dependence. The system works by storing excess solar power generated during the day so it can be used at night time. Once the batteries are full, surplus power generated from the solar panels is diverted to the grid. If the household demand exceeds solar generation and battery storage capacity, then power will be drawn from the grid. If there is a black out, then the batteries will provide backup power.

The battery trial has already generated a lot of interest, with WA Treasurer and Minister for Energy Mike Nahan being one of the first to visit Josh’s House to check out the system. You can find out all about the trial and hear what the Minister had to say about it on the latest episode of Josh’s House online video series, plus download a copy of our factsheet.

In a national first, you can also monitor the battery system via an open source online data display. The customised data portal is another new feature of the Josh’s House project designed to allow others to observe how Josh’s House is performing. It provides detailed information on a range of operational parameters, including temperature, power, gas, and water use, plus greenhouse emission and off sets. Trends can be observed over days, weeks and months, providing a unique insight into how a high performance family home operates in real life. The electricity display shows where the power is being sourced from (PV’s, battery or grid) and the level of grid demand and export compared with the same time last year before the batteries where installed.

The development of the online data display has been the result of three years work, with preparations starting before the house was even built. “It has been major exercise” according to Josh Byrne, Director of Josh Byrne & Associates and Curtin University Researcher. “Getting data from a house onto a screen may seem straight forward, but the reality is it involves a huge amount of planning and the coordination of multiple professionals including technicians, computer programmers and graphic artists”.

Development of the data display system has been part of Mr Byrne’s research with the Curtin University Research Policy Institute (CUSP) and the CRC Low Carbon Living (CRCLCL). The system has been designed as a communication tool to share the learnings of the project with others, and as a feedback tool to help his family understand how their actions impact on the performance of the house, especially energy and water use. The outcomes will inform other ‘Living Laboratory’ type CRC LCL research projects that Byrne is working on.

“Like everything else at Josh’s House, we see this part of the project as an important opportunity to showcase new technology and design concepts to support low carbon living. Most importantly we want to be able to share the data on how high performance homes operate in a real-life setting. Sharing the data ‘warts and all’ is the best way to do this.”