uses in mind. 3. Identify and examine poten- tial energy conservation measures (ECMs) that might reduce energy use and/or cost. 4. Perform engineering and eco- nomic analyses of potential ECMs. 5. Compute carbon emissions to profile a baseline carbon footprint and future impact from the ECMs. 6. Prepare a prioritized list of suitable ECMs. 7. Prepare a report of the analy- sis process and results. An energy balance estimates ma- jor energy users, then balances them against utility and fuel bills. It should include all energy sources such as electricity, diesel, natural gas, and re- newables. Because large energy users at a mine may dwarf the myriad of smaller equipment and there may be gaps in available energy information, the full version of an energy balance typically used in traditional energy audits may not be of material value. Site visits and interviews build on this analysis. These visits enable auditors to gather more detailed in- formation about large energy uses, discrepancies, suggestions for im-
provement, and more. On-site ob- servations, measurements, and engi- neering estimates include basics such as lighting, HVAC, and motors. Min- ing energy audits expand on this to include haulage, pumping, crushing, processing, ventilation, conveying systems, and other systems. Based on this work, energy audi- tors then prepare a report outlining the ECMs they identified. This re - port presents the estimated costs and benefits of the ECM projects. Results should provide information that man- agers need to decide if the site should apply the ECMs. Not a perfect process As with any tool, limits exist. En- ergy-audits may not factor decisions made in mine design, planning, and purchasing activities. Such factors may add more complexity than the scope of the audit permits. In addi- tion, audits typically don’t capture the energy impact from the dynamic na- ture of a mine site. For example, auditors can’t gen- erally account for changing ore
EFFICIENCY, CONTINUED from PAGE 23
This is not an issue for building au- dits. Given the complexity of most op- erations, a mine energy audit team should understand the inner workings of mining and processing operations. The team should also have knowledge about the broad spectrum of equip- ment in use as well as alternatives to them. A strong energy audit team in- cludes specialists in mining, process- ing, electrical engineering, fleets, and sustainability. Having this depth of experience on the team creates a greater under- standing of the mine complex, which leads to better outcomes. This ensures a thorough analysis of the energy-us- ing systems. An energy audit general- ly includes these steps: 1. Collect and analyze historical energy use to create an energy balance, and/or evaluate the energy consumption by identifying the largest energy-con- suming processes and equipment. 2. Study the mine site and its operations with these major energy
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The Alaska Miner
Spring 2023
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