Solar Battery Cooling under AS 5139
Jonathan on Google Hippisley
If the Australian regulators of today had been around at the dawn of the 20th century when the internal combustion engine was invented, most people would probably still be using horse drawn transport, because motor vehicles would have been so over engineered to make them safe from the highly flammable substance powering them, they would never have come within the price range of ordinary people.
Current Australian regulations (encapsulated in AS 5139) are such that house batteries may never be affordable by ordinary people in the depth required to get through the night, and climate warming mitigation targets are unlikely to be met.
How many homes were lost in the Los Angeles fires, which may have been made worse by weather conditions at least in part exacerbated by global warming? How many houses have been lost to lithium ion battery fires? How many of those were attributable to Tier 3 batteries? How many caravans and sailing boats have been lost to fires caused by lithium iron phosphate batteries which would be classified as Tier 3 if they were covered by AS 5139?
AS 5139 is not smart. To get to be Tier 2, a battery has to pre-assembled, “tested” and included on a list. To get to be Tier 1 a Tier 2 battery has to include an inverter and “internal safety switches”. The standard is oblivious to battery chemistry and takes no account of real world data on differing probabilities of thermal runaway occurring in the different battery chemistries.
A Tier 3 battery must be in a structure such as a shed that is away from the house. In the Australian climate this adds a huge construction cost and energy overhead. The thermal insulation requirements for the structure will be at least as onerous as those for an energy efficient home, and the cost of keeping the structure cool will add a significant overhead. On a hot day the cooling system on my circuit absorbs 3kW or 60% of the maximum power produced. If the temperature stays high in the afternoon and evening, I have to buy up to 10kWh from the grid at peak rates. This seriously degrades the economic benefit of the system.