Project Title : REDUCING ENERGY CONSUMPTION & CARBON FOOTPRINT THROUGH IMPROVED PRODUCTION PRACTICES

The US coal mining industry consumes approximately 142 billion kWh per year of energy. The US Department of Energy estimates that the industry‟s annual energy consumption can be reduced by 49% (24.6 billion kWh/year by using currently available best practices and a further 44.8 billion kWh/year with more research). This constitutes nearly $3.7 billion of potential savings on coal production costs at 5.3¢/kWh of energy. Additionally, with climate change regulation on the horizon, any benefits from energy savings in the near future are compounded by associated reductions in CO2 emissions. The overall goal of this project was to evaluate a variety of operational strategies and produce a ranked list of high impact energy saving improvement options for surface coal mining operations. The research team conducted energy audits of truck-and-shovel overburden removal and highwall miner operations. This information was used to develop regression models describing truck and shovel energy consumption. The research team then built a stochastic simulation model of the truck-and-shovel overburden removal operation and used it to assess a variety of improvement measures by simulation experimentation. Results of energy audits show that the average fuel efficiency for trucks, shovels, and the overall truck-and-shovel system are 37.14, 39.29, and 19.09 tons/gal of diesel, respectively, for overburden removal at the study site. The highwall miner‟s energy efficiency is 0.443 tons/kWh. Valid fuel consumption models for shovel loading and truck haulage have been formulated based on these energy audit results. Valid stochastic process models of truck-and-shovel operations have been formulated to study fuel consumption. The following strategies, in decreasing order of impact, provide the most energy savings for truck-and-shovel overburden removal at the mine: (1) shorten haul roads; (2) increase shovel capacity; and (3) increase shovel utilization through optimal truck matching. Additional data will be required to adequately describe operator effects on fuel consumption. There are indications that power quality affects the energy draw for highwall miner operations but further study is required to adequately understand this.