not sure how you can do a calculation - the battery/solar...

not sure how you can do a calculation - the battery/solar operation is based on a BOOT model (build-own-operate-transfer) and I assume that CBE paid for the entire thing upfront, so the monthly (?) cost they are paying would include a combination of supply of electricity, the capital cost of the battery/solar as well as the ongoing maintenance.

They are still flagging operating cost savings, but as that payment is partially for an asset, the actual monthly cost may be higher (the offset being is that end up with the battery/solar asset at the end of the 10yrs at no cost).

Smart way to do it (i.e. spread the capital cost over 10 yrs and also have 'experts' manage the solar/battery operation), so hopefully more companies will do this if project financiers are willing to stump up the money (clearly if they can do this in Mozambique, can't see why more miners are not doing it locally in Oz)