Everyone should just be able to make their own energy and eliminate reliance on large centralized power plants. Or just light a candle.... but that won't charge the cell phone will it.

I'll wait to get excited until they actually come to the market but I hope the hype lives up to its promise.

Sure I heard about this several years ago but nothing eventuated- hopefully this time will be better. The problems I see are the large footprint that makes it unsuited to many domestic installations & the problems of replacing the electrolytes; plus the
public/ business acceptance.

Nice. I don't get how using non-toxic materials to make these is so important, you aren't going to be eating them, right? Anyway, there's already a feasible way of storing energy from these devices, and it's been around a long time. Hydrogen. If the electricity is used to generate hydrogen via electrolysis, then it can be used to generate power, or heat, later. (Watch, some hippy will claim it'll be turned into hydrogen bombs or something!) :D

Hydrogen... from what I've read, a nonstarter really. Expensive to generate, transmit & store the smallest atom in the universe; no great strides have been made in hydrogen vehicles, all of which are heavily subsidised. As technology moves on better ways may be found, though.

I'm wondering how large such a system would be for the consumer market. I currently have two Tesla batteries up against the wall in my garage. If I would have to fill my garage with vats of these liquids to replace those two batteries, it's still not a workable solution.

Pumped hydro claims 87% efficiency and if it rains you get the bonus free hydro power. You dont need to use fresh water, so it can be built anywhere with water including desert regions if you have the necessary height difference.

"Or just light a candle.... but that won't charge the cell phone will it." --- A cheap commonly available thermoelectric device will make a candle do just that.

Vanadium flow batteries are a relatively mature technology and makers claim low toxicity. See Red-T Energy Systems in the UK who have just formed a partnership with Avalon Battery in the US to form the new UK/US business Invinity Energy Systems - see https://invinity.com/creating-leading-vanadium-flow-battery-company/ . One of the potential advantages of vanadium based systems is that you can re-charge a site by replacing the fluids if using it for backup power, although I'm not sure if this is being offered by Invinity.

Lots of companies have given up on this approach. We may learn a lot more about what is possible with batteries during Tesla's Battery and Powertrain Investor Day, now loosely scheduled for May, 2020. They are likely to announce batteries with many more years and cycles of life, plus higher energy density, safer materials and much lower cost. If Tesla is successful, it will push off the appeal of many alternative storage concepts, like flow batteries.