To be fair, Solar power plants never claim that they can generate power 24 hours a day - I think even Donald Trump would be able to understand that solar panels don't generate power at night
Equally, coal and gas-fired power stations claim their rated capacity as peak generation output, not accounting for downtime. In reality, especially for older power stations, failures are not uncommon, especially for coal burners during hot weather when power demand is high:
Of course solar and wind farms fail also - "when the sun doesn't shine and the wind doesn't blow" - but in these cases the failures are predictable from weather forecasts and AEMO can plan accordingly. And in other cases, failures occur as the result of external events such as extreme weather:
Agreed. There's no doubt however that Genex have a business case. Without it, no-one (including NAIF) would lend them money. You can, however, get a general idea of the opportunity for price arbitrage by looking at public sources for power price variation by time of day (especially the morning and evening peaks when Kidston pumped hydro will be planning to operate).