[barbegal]

Connected to the grid yes but usually the interconnect is simply enough for running the mine not enough to cover many megawatts of storage capability. The battery storage companies have found that there is an abundance of fields and brownfield sites close to existing substations to place their batteries where the cost of connecting to the grid is minimal.

[sophacles]

> Connected to the grid yes but usually the interconnect is simply enough for running the mine not enough to cover many megawatts of storage capability

Mines can use a LOT of electricity. I found a presentation from EPRI[1] talks about varoius electric vehicles and machines used in underground mining. One slide references a "mining system" that alone draws 5-10Mw. Even if you take that as "the whole mine uses 5-10MW", it means that it's grid connected well enough to handle Mw of storage.

[1] EPRI is a respected R&D non-profit in the electricty sector. The slides: http://mydocs.epri.com/docs/publicmeetingmaterials/1203/jkn2... the slide I reference is #14.

[jcrawfordor]

The hoist at this mine is 2.5MW, there's typically some ore processing on site, mines end up requiring a lot of ventilation and cooling, dewatering, most of the work vehicles used in deep mines today are electric (and these aren't light battery vehicles but heavy equipment trailing high voltage cables), I think it's very conservative to say that the mine consumed over 5MW when it was fully operational.