Mining industry looking to renewable, sustainable, uninterrupted power
Andy Birtles, mining advisor to ROST International, presents an elegant solution to supply power to mining projects in areas where conventional power supply is limited or intermittent.
Mining projects often have significant power requirements, on the order of tens of megawatts (MW) and millions of kilowatt-hours (kWh) per site per annum. Mining projects are also often located in remote areas, far from established electricity infrastructure.
At the same time, many countries rely on fossil fuel generated power, and mines in remote locations must depend on local power utilities and/or governmental agencies to install the necessary infrastructure and supply power at a reasonable tariff. Where this process is protracted or inflexible, the usual alternative is to use large diesel generators to provide the required power. However, these are expensive to fuel.
Energy costs can represent 20-40% of mining operational costs, and forecasts indicate that this will rise further as traditionally reliable suppliers become increasingly unable to guarantee uninterrupted electricity. As a result, reducing electricity expenditures and increasing reliability are now major goals for mine operators.
Mining companies are realising that where local fossil fuel generated power is expensive or unreliable, the alternative is to develop and install a source of renewable energy, backed up by diesel or heavy fuel oil generators, at or near their mining operations. Integrated renewable solutions can enable mining companies to meet sustainability goals, while also securing a reliable energy supply and a reduced long-term energy price.
Renewable alternatives to traditional power include intermittent sources such as wind and photovoltaics (PV), as well as Concentrated Solar Power (CSP), which, unlike PV and wind, operates 24/7 regardless of weather. CSP technologies have advanced considerably in recent years and can be used to generate 100% of the power requirements of mining operations, particularly in areas of high Direct Normal Irradiation (DNI). The following image (courtesy SolarGIS) presents the regions where solar power plants would be most efficient.
CSP uses lenses or mirrors and tracking systems to concentrate sunlight, then transfers the resulting heat to a fluid medium that is then used both to spin a turbine immediately and to be contained in a thermal storage system to power the turbine after sunset. Thermal storage efficiently allows continuous uninterrupted electricity generation without the use of batteries. The problem for the mining industry is that conventional CSP requires large amounts of water and works best at power sizes greater than 50 MW, requiring land use of 200 hectares or more.
An Ideal Solution
A unique CSP solution has recently emerged that shown exceptional promise for the mining industry. 247Solar Inc’s (247Solar) advanced turnkey 247Solar Plant™ eliminates both of the problems described above. First, rather than using steam turbines, it uses gas, or air, turbines, slashing water requirements by as much as 90%. Second, the Plant is a pre-engineered, standardised system that can be deployed as a single unit of 400kW, or as tens of megawatts by combining multiple units. The Plant operates at atmospheric pressure, has few moving parts, and easily adjusts to the varying power demands of a mining operation.
Benefits offered by the 247Solar Plants include:
Guaranteed Secure and Clean Power
247Solar Plants are ideally suited to mining applications in remote areas and where electricity supply is unreliable. They provide highly reliable, uninterrupted power for mining, processing, and ancillary operations at very low operating costs. In addition to thermal storage, their generators are designed to burn a variety of fuels during to remain operating during periods of prolonged cloud cover or limited direct sunshine. Reliability is further enhanced by constructing the Plants close to the mine, and through the redundancy offered by the system’s modular design.
247Solar technology allows mining operations to significantly reduce their carbon footprint and “greenhouse gas” emissions. 247Solar technology is wholly sustainable, requires no water for its operation, produces no waste, requires minimal maintenance and can help contribute to the mining company’s Corporate Social Responsibility initiatives.
247Solar Power Plants are modular and can be built in stages, to meet the need for development, construction, pre-production and full production—spreading capital expenditures over several years. Any surplus power can be used to supply local communities and industries, potentially providing additional income. Local communities and other social facilities can continue to benefit, even after the mine has closed, as the Plant(s) can continue in operation or be wholly or partially moved to another site.
247Solar’s first commercial demonstration plant of 400kWe is being constructed in Ouarzazate. Morocco, and is anticipated to be online in mid-2020. It is expected that the pilot Plant will demonstrate that power costs can be considerably reduced, with fuel cost savings (over conventional costs of power generation) in the region of 80-95%.
To date, renewable energy provides only a small fraction of available power at mines. The costs of solar, wind and battery storage systems have been declining at an unprecedented rate, which has encouraged an increasing number of mining companies to test renewable technologies at their mine sites. Recent reports by Fitch Solutions (2018) show that the mining industry’s transition to renewables has begun, and solutions like 247Solar Plants offer opportunities to pick up the pace in the coming years.
Andy is a mining engineer with more than 35 years’ operational and consulting experience in the mining industry. Andy has extensive experience in mine operations, planning and design (both surface and underground). He has also been involved in the valuation of mining projects and operations and exercises and the development of Public Reports and Technical Reports.
ROST International will be attending Mines and Technology in London on 25th to 27th November. We would be delighted to discuss the latest developments of this exciting technology. Come and see us on Stand A10