Quite simply put this is what they ask you to do. To the point that the Australian government will heavily subsidise (30%) home battery installation.

Remember Australia has over 10x the rollout of solar than china (per capita of course). It’s not hard to achieve this for any competent government. Bluntly China’s government is corrupt and inefficient (usa is even further behind china since their current government is also corrupt and inefficient).

This rollout of cheap solar in Australia is causing power prices during a global energy crisis and a datacenter build out to plummet.

And fwiw i don’t think Australia’s government is perfect. But it should set the bar to other nations of ‘what could be’. You could have falling power prices right now if you enabled a government to encourage what is currently by far the cheapest form of electricity (solar).

This is what I am doing. 42 kWh battery, 6 kW solar and fully electrified house, 2x EVs. I am able to charge cars at work and so in the depths of winter I am able to run the house by charging during the 3 hour window. There have been just a couple of cold (~2-4 degC) days when the battery was depleted 1-2 hours before the window starts.

As the weather warms and we get more solar exposure we will easily be in excess. We get a very small export rate with a bonus for no energy consumption during peak evening hours which can offset the fixed daily charge.

There are a lot of gotchas that you need to be aware of. 42 kWh is nominal capacity not the actual usable capacity. House load, max grid import and export capacity, max inverter capacity, AC or DC coupled panels, battery charging profile, battery temp are all factors in how much you can charge in the window. For example I have max 15 kW grid draw, with a 10 kW inverter that can charge the battery. I can put in max ~30 kWh into the battery, so I also run other loads in the house to use the other 5 kW capacity. If I go over 5 kW house load the battery charge is clipped to maintain grid import limit.

Forget 3hrs free. We lived in the tropics in Australia with a ~6kW system and often had negative quarterly invoices (i.e. got paid by our retailer) ... esp. in winter months. Aircon, pool, appliances all electric. At the very least the pool pump ran free all year round.

Edit: should add, that's straight solar no battery

The Australian grid presently curtails ~7-18% of production every single day between 11:00 and 14:00.

I believe that incentivizing people to acquire batteries is precisely the purpose of the policy. It's good for the grid for there to be a lot of storage at the edges. As I understand it, the 24kWh cap is subject to annual review, with it being reduced/the policy being soft phased out once curtailment is no longer necessary.

Just for reference our fully electric household (including cooking, water and aircon). Highest usage this month on a very hot day was 25kWh. (Disclaimer: I am not in Australia. Already cover most of it with roof solar. No battery yet)

Yes - the regulated offer is capped at 24 kWh per day but some retailers such as Globird and CovaU are offering plans which include up to 50 kWh per day of ‘free’ electricity. With a large enough battery and inverter you could just end up paying daily supply charges of $1.65-2.20 per day.

I pay about 38c per kilowatt plus $1.70 per day for the connection fee. So by that maths, you'd save 8×0.38=$3.04 per day. A 10kWh battery is in the ballpark of $4000. So it'll take about 4 years to break even. Then you'd just have to pay the connection fee, which seem to be increasing every year.

An ev charging at 7kw will consume 21 of the 24kWh. Now, if you don't drive massive distances every day then this might not be the best deal, but I can see how this might be worth it for someone commuting 200km a day for example. Taxi drivers, and the like will also probably benefit.