Ann: Brisbane Resources Round Up Presentation 181016, page-12

VYR

Thank you for your very helpful report - much appreciated and it helps understanding of the options.

I had not considered the opposition of turbine insurers to blasting in the area. This seems overly conservative to me. Clearly one would not want blasting in the vicinity of the turbines to cause excessive ground vibration while the turbines are running. But as I understand underground mining blasting, it occurs over a short duration (coupla minutes) once a day between shifts (ie no one underground). Turbine (or as pump in reverse) and linked generator/motor would generally operate for less than half of a 24 hour day leaving big time gaps when they are not operating (though noting that the time of operation is generally kept quite flexible to deal with pricing opportunities (two ways: both cost in to lift water and price out when generating). And, I would think that start-up/shut-down sequence of these would be approx 15 minutes. So from an engineering and commercial point of view it would seem feasible to sequence the two events (PHES and mine blast) so that they do not coincide in time. Also it is eminently feasible to monitor blast-vibration effects at the turbines to ensure they are below a threshold. 

Of course insurers generally want to reject all risk rather than manage it.

I wonder whether a suitable outcome that does not preclude underground mining cannot be achieved.