Our PV+battery has been up about little over a week now. Today was hot and sunny; the first day of a 4-day heatwave and topped out at 31C while staying pretty humid.
We had AC on in a couple of rooms most of the day, using 26kWh of energy for all activity. The PV array produced nearly 44kWh of energy. We consumed 16kWh from the battery. At about 4:00pm, the battery was full.
Presently, the battery is discharging as we consume electricity from it, and it exports to the grid. Over the day, and across two price spikes we've exported 23kWh of energy. It's clearly not going to be any less in coming days.
On less sunny and hot days, it looks like we'll generate around 2x our consumption. On hot days like this, it will be even more (
Yes, it's going to take a handful of years to recover the outlay, but at this rate, we’ll both completely offset the cost of electricity supply to our house as well as earn enough FiT to offset a significant proportion of electricity supply for our guest cottages.
In NSW (and I believe other states), there are significant state government rebates on batteries alongside federal rebates on PVs. If you have the chance to invest in solar+battery, now is as good a time as any.