In my last blog post, I discussed the prolific energy waste in the sugar industry (96%) with their very effective disposal of a valuable renewable resource, bagasse, blown up their stacks. Today I want to share about industrial energy waste in the mining sector, let’s look at the Platinum Industry. Recently I addressed a group of students at University of Cape Town, Western Cape who attended a workshop on the developing the Business Case for Energy Productivity and shared some examples of energy waste in the Platinum Sector. This was one of the case studies shared.
This particular operation has several major energy uses; one is an oxygen plant. Oxygen is used for a metallurgical processing of the platinum ore. The oxygen plant at this operation was consuming some 18.2MW of electricity 24/7 and this was assumed to be efficient. Its electricity cost was around USD6.1 million with GHG emissions of 160,000T per annum. It had used this level of demand for a few years previously. On closer scrutiny, we found that the blow off valve on the oxygen generation was opened 40%. Some research and data analysis identified that the contractual arrangements meant that the plant operator didn’t have a price signal to operate efficiently. Also, there was a communication problem between the oxygen plant and the processing plant operators, which forced a certain operational philosophy.
The plant demand dropped 5MW or 27% over 3 months when a series of interventions were put in place to address the above issues. These interventions required no capital investment and delivered USD1.7 million p.a. energy cost savings and 43,000T reduction in GHG emissions. In addition, a further 4.5MW reduction is now in implementation which did require a capital investment. The intervention had an 18-month payback, bringing total savings to 9.5MW or 52%, saving or 80,000T in GHG emissions per annum and USD3.1 million in energy cost savins. The combined project had a positive cash flow so the IRR is not relevant and NPV was calculated at USD18 million at 12% discount rate.
This is one of serval examples I could give in the Platinum industry. And all support my vision that 50% of the world’s energy can be saved, cost effectively, profitability with existing technologies. Prolific energy waste is all around you, one just needs to look.
