Excess capacity could be built over time, i.e. as more and more PV or wind systems come on line.
Alternatively, as the excess PV and wind capacity is built, additional pot groups could come on-line in the smelter to take advantage of the new generating capacity.
One of the big benefits of renewable energy - both wind and PV - is that it is scalable. From residential roof top to large commercial or even utility scale solar and wind farms. Ideally, the battery/smelter can be scaled up accordingly.
