Episode 7 – Battery storage – Tesla Powerwall 2

2020 – Battery options modelling

In the middle of all that work on evacuated tubes, we learned that change was imminent in the SA Government Home Battery Scheme. To qualify for the maximum $6k subsidy, applications had to be lodged by 15th April.

Our modelling indicated that our 21kW PVs were generating enough power to usefully support up to about 55kWh of battery storage, corresponding to 4 x Tesla PowerWall 2 batteries. In cost-benefit terms, a sweet-spot would be with 2 batteries. In the depths of winter in July we’d still generate enough net power to fully charge the batteries for use overnight.

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Episode 4 – Major PV upgrade

Adventures with an environment-conscious inner-urban community

2019

For years we’d been tossing around options for increasing our solar performance without losing our high feed-in tariff (56c/kWh) for the 4.8kW PVs that were installed when the Christie Walk community built the Sturt Apartments in 2006.

But by 2019 it became clear that preserving the high feed-in tariff was a false economy. We’d be better off financially and environmentally if we replaced the PVs and inverters with a high performance 21kW system.

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