Ann: Nebo-Babel Scoping Study, page-116

The problem is getting an outside company to do whatever the 'green' solution is. It comes at a high cost. Because the isolated mining companies already have their own power station and electricians, they could easily just add solar panels, wind turbines, batteries into the mix of their own power station. They might need to employ one or two specialist electricians that are competent/qualified in the solar/wind area, but that is not going to be a huge spend. As soon as you engage outside companies with their own 'specialists' and a profit to be made on top, the savings deteriorate quickly. solar panels in banks are not rocket science to competent qualified electricians, likewise wind turbines and batteries. The batteries are not there to add days of power for low natural output times, they are there to add a bit of backup for when some clouds drift across the solar panels or the wind drops for a couple of hours.
The real problem is that a simple system, which is what is needed to cut power costs drastically, still involves the full number of generators that might all be running for only a few days of the year. Most of the rest of the time solar and wind do it all, or a few generators (assuming a bank of 2-3MW generators) work for some of the time. The cost for a 20mt/a plant and running ALL the machinery off it, excavators/shovels, trucks, in pit primary crushers, conveyor systems, processing plant etc, would cost $1.5b to set up, yet it would save over $300m in fuel costs every year, so over 20 years it would save $6b in fuel uses at current prices, yet I'm a believer in peak oil and the price of oil going much higher!!
But I'm talking 20mt/a, as that is the size of plant this grade of ore warrants. Paying off the system can be done by high grading the first few years, or even set up the full system over the first few years from cashflow, but plan for it properly from the word go!!