I agree there ... GNX would benefit from a chemical battery to...

I agree there ... GNX would benefit from a chemical battery to provide fluctuation control and also more immediate response to power fluctuations due to weather... I would view that PH would be used in a manner similar to BESS, with the advantage that a full discharge (8 hours of supply @250mW) from top reserve to bottom reserve can be done fully (and more regularly) without harming the effective life of the battery. Time to refill reserve (and energy required to do so) has not been disclosed in their promotional material.

Most of the PH assets in Australia were in the hands of state governments, who also were the operators of the coal fired generators... PH was in effect a reserve in the event of plant failure to pickup some of the lost base load or when power demand dropped off - the pumps were turned on to maintain coal plant at the same speed... the water would be used to generate later... Wivenhoe Dams PH history has an interesting example of this... https://reneweconomy.com.au/wivenhoe-pumped-hydro-big-little-plant-didnt-30606/

how they perform for arbitrage is not well documented due to their state owned histories - I think I remember reading about the Snowy project making good use of last summer somewhere - the stated 30 second start up time of GNX PH would indicate that it would be a reasonably good fit to this role - I think we have discussed before that once production costs are factored in - PH is in the vicinity of $80Gwh? So at current peak prices - ST to MT there is definitely still profit to be made

I do hope that IFN have at least put an offer on the table to GNX for a capital lite form of PPA... or as mentioned... ~$88m for a business with the current development potential of 150mW wind, 320mW solar+250mW PH battery and already having 50mW solar in operation (into NEM it looks like no less) - I think IFN should have a look over this with a ruler. They are 1/10th our size and I feel the PH option validates the use of solar... the wind development asset would the around the same size as Alinta, Capital WF or Lake Bonney 2 (30-40Gwh a month)... so it would become one of our larger producers... and being in remote location - could use bigger turbines!