"water is wet and all that..."

...and it's a very good energy store when much of your energy demand is for heating/cooling with target temperatures in the "habitable zone".

The only real challenge (but a big one) is getting the incentive structures right so that they are not "hacked" (e.g. pretending to be a dispatchable consumer at high supply but actually just switching to the conventionally billed socket at times of high demand) and keep inevitable oversteering/pork cycle within a reasonable margin.

Solar power is not irregular at all, and is entirely predictable with a weather forecast. Unless Australia has an entirely different usage pattern to the rest of the developed world- businesses are perfectly aligned to use the solar power generated during the peak.

From the article: "the growing peak demand that comes at the end of the day, as the sun sets.". So the solar production of electricity peaks earlier than the end-of-day consumption peak.

There is a company in Australia that have improved flow batteries technology to the point where it can be miniaturised down to the size of a fridge freezer (previously they were the size of shipping containers) ten shipping containers full of them are able to store 3.2 megawatt-hours of energy and discharge a megawatt of power for over three to four hours which is roughly enough to keep 500-600 average homes going for the afternoon during the end of day consumption peak.

They are perfectly suited to be paired with solar/wind/etc where they can store up the days usage and discharge at a regular rate throughout the evening peak when generation is reduced. And as for reliability, unlike lithium-ion, flow batteries can last for 20+ years with unlimited cycles.

I assume you are taking about red-flow?

I head about them several years ago but haven't seen much since. Do they have the scale/ pricing to sell to the average consumer yet?

I am indeed. I think they got some press coverage three or four years ago. I personally discovered them by watching a documentary on YouTube that featured their technology and discussed its future.

I know that they recently raised some capital to invest in increasing sales. However I think a large proportion of their target market are grid scale and remote outposts for telecommunications/industrial applications.

That could be because their residential solution still cant beat something like the Tesla powerwall on price. However, I believe when investing in something that you expect to have longevity in the 20-30 years range it's better to go with something a little more pricey that is proven to last that long without degrading of performance, so on that point the flow battery wins.

It's like with solar panels, you can pay a premium upfront and get panels that will be producing the same output in ten years time like my parents did, or skimp on price and end up with a 30-40% reduction over the same time period like their neighbour.

Sure, there is an evening peak when people get home and start cooking/turning on their homes etc- which can't really be offset with solar (without using storage, battery/hydro). Doesn't negate the fact that solar generation pretty much perfectly matches business usage.