IM 2018 January 18 | Page 38

POWER FOR MINES independently tested to pass accelerated life and stress tests beyond industry standards. Caterpillar’s solar PV offering is a key component of the Cat Microgrid technology suite, an innovative lineup of power systems that adds environmentally friendly solar panels, state-of- the-art energy storage, and advanced monitoring and control systems to Caterpillar’s traditional line of reliable power generation equipment, including HFO, natural gas and diesel generator sets, switchgear and automatic transfer switches. The Cat Microgrid technology suite is designed to reduce fuel expenses, lower utility bills, decrease emissions, and reduce the total cost of ownership while increasing energy efficiency in even the most challenging environments. “A key differentiator in Caterpillar’s offering is the Cat MMC, which keeps loads continuously energised with high-quality power at the lowest cost. It manages the flow of power from every source in the system, including the main grid when connected. The Cat MMC determines optimum recharge times for the energy storage systems while managing power during times when solar energy is not available.” The MMC also uses Cat Connect technology for real-time collection and communication of on-site performance data that can be monitored and analysed remotely. “The economic viability of remote mining operations depends on the cost- efficient generation of power,” said Tom Frake, Vice President of the Global Power Solutions Division for Caterpillar. “Caterpillar’s solar technologies provide a scalable, s ustainable power solution that significantly reduces fuel consumption while delivering the reliable power needed to support mining sites.” Renewable and storage technologies ABB says “for off-grid mining in particular, renewable and storage technologies present an ideal opportunity not only to improve the mine’s environmental footprint, but also to reduce energy costs while improving power quality. “For off-grid mines operating in remote locations, the cost of electricity can reach $300/MWh and consume up to 15% of mining revenues. Lowering energy costs will not only increase viability of mining operations today but also help future proof them against rising fuel costs. “To test the viability of storage plus renewables for brownfield mining sites, ABB considered four scenarios that were optimised using HOMER Pro2 microgrid modelling software. The benefits compared include: n Fuel saving (and associated reduction in CO 2 emissions & maintenance costs) n Reduced Levelised Cost of Electricity (LCOE) with an attractive IRR n Improved power quality. “The results showed that the highest 36 International Mining | JANUARY 2018 BESS + solar PV benefits for an off-grid remote brown-field mine (~5 MW demand example) investment IRR of 36% was possible by installing a Battery Energy Storage System (BESS) where the main benefit comes from improved generator operational efficiency that results in a reduction in maintenance costs. Alternatively, by combining this with solar PV generation we can additionally substitute expensive diesel fuel with cost competitive solar PV thereby delivering the largest reduction in fuel consumption (28%) and LCOE (11%), while maintaining a healthy IRR (16%). Additional power quality benefits provided by a BESS such as reduced stress on the electrical installations across the mine site and associated reduction in maintenance cost and down-time have not been modelled in this study.” Finally, ABB’s analysis shows that the most important factor impacting system design is the price of delivered diesel followed by the cost of the installed solar PV system. Two conclusions can be drawn from the business case: n Mining companies have the opportunity to start transforming their mines today as solar PV now delivers a lower LCOE than diesel n Deployment of solar PV + BESS is an excellent hedging solution against diesel price increases and/or future carbon costs. ABB concludes that “powering remote mines with diesel generators provides a proven and reliable energy source, but leaves the mine operator vulnerable to diesel price fluctuations, fuel supply risk as well as uncertainty around future carbon taxes. It also fails to capitalise on the economic and operating benefits that BESS and solar PV offers today and potential cost savings from carbon taxes in the future. The figure presents an overview of the economic Up to 28% reduction in fuel and CO 2 possible when combining diesel with BESS and solar PV benefits and capital requirements of the four scenarios tested. “In some cases, mine operators may prefer the incremental hybridisation route as it allows more gradual changes to the operating system and strategy. This analysis shows that it makes sense to consider BESS in the first step without additional renewable energy capacity as this offers the highest IRR. Ideally, the use of a flexible BESS, such as the ABB PowerStore, would allow the storage capacity to be increased if renewable energy systems are later added. “In terms of renewable options, wind has also proven itself to be effective in the mining sector, particularly in those areas with high wind resource and low solar resource. Due to historically lower costs, high scalability and relative ease to gain approvals in remote locations, wind has accounted for 59% of installed renewables in mining to date. Where mine lives are shorter than 10 years new business models allowing for relocatable solar PV to be installed could be considered. Once you have found the right renewable choice for your location, combining with a BESS can provide additional cost-savings that mining operators can benefit from today.” For more detail, see http://register.e.abb.com/ ABBMicrogridBusinessCaseforMining Hydro power In 2016, Gilkes Hydro won a contract to supply its Compact Turgo turbine to AngloGold Ashanti in Mali, where it will generate in the region of 150 kW. At the time, the company said “we are