News: AGL Australia's New South Wales awards $2.5 bln battery contract to Shell, page-21

agree with Christos here... general maintenance is extremely minimal... no moving parts... it purely becomes an equation of attrition due to use (higher discharges will accelerate battery aging).

Also technically, OPEX and COGS are separate items on the profit & loss... but for the sake of this discussion - I am saying that profitability will be HIGHER for BESS due to lower OPEX + COGS than Gas Power Plant. Plenty of gas plants dont even get turned on unless the NEM spot price is over 100... clearly there is a reason for that, with 30 min NEM pricing and only a ~4 min startup time... very easy for a gas plant to operate like that.

Big benefit of BESS though - is that the batteries are modular... many packs... one fails - it gets isolated, battery runs on a lower capacity until the faulty one is replaced. AFAIK - there isn't even a need for full shutdown due to the isolation.

UQ did a case study on their Mw scale battery that they run at St Lucia... very interesting read if you have the time, and it also details an instance where a battery pack did fail.