As a very affordable form of electricity generation, solar PV is being widely adopted by businesses globally. However, is it applicable for remote mining operations? In Africa, an abundance of solar resources makes this an important question for remote mining operations who need to carefully consider energy generation, writes Daniel Goldstuck.
If a mining operation is located close to a utility grid, there could be an option to commission a new power line or grid connection. While this may seem like the most obvious electricity supply option, there are many uncertainties in the creation of a new power line, and even in connecting to an existing substation. As such, many mines in Africa opt to rely on decentralised power, either in the form of diesel or solar PV-hybrid generation.
With the affordability of solar PV solutions, it makes sense to explore a solar PV system for all mining operations in Africa. However, to provide electricity during hours with little solar irradiance, solar PV needs to be used in conjunction with a backup energy supply. Energy storage – particularly in the form of lithium-ion batteries – is quickly becoming an affordable option.
This is partially due to the falling costs of energy storage technology. The increased interest in electric vehicles, as well as global uptake of off-grid electricity, have sparked a sharp decline in battery costs. Battery manufacturing capacity is expected to increase significantly by 2021 from just under 150 GWh/year in 2018 to 700 GWh/year in 2021.
Increases in average battery plant manufacturing size, from around 10 GWh/year to just under 30 GWh/year, is also a contributor to the significant decreases in the costs of lithium-ion battery cell prices. Since 2013, the cost of lithium ion batteries fell from around USD446 per kWh to USD112 per kWh in 2019, according to Bloomberg New Energy Finance.
With costs of storage rapidly decreasing, energy storage provides a much more stable cost profile than grid-powered or diesel-generated electricity, which both have unknown future cost fluctuations.
However, should the application of a solar PV and battery storage microgrid system for high renewable energy consumption be unfeasible for a mining operation, a smaller battery storage installation can still reduce mining operational costs by extending the life of generators through supplementing spinning reserve. This can also create a ~2% diesel saving: a 2 MVA battery spinning reserve on 6MW of average power requirement could save ~260 000 litres of diesel per annum.
A solar PV and energy storage microgrid ensure the control of all power and energy sources to balance the load. A high concentration of renewable energy, such as solar PV, in conjunction with storage, enables complete control of energy costs, eliminating logistic risks and price fluctuations. This reduces much of the risk of electricity supply for both planned and existing mining operations, moving them down the resource cost curve, reducing break-even ore-grade and ultimately increasing the life of mine. It is a game-changing solution for remote mining in Africa.
Daniel Goldstuck is a director and head of energy storage and microgrid services at the Sola Group. The Sola Group represents cutting-edge solar technology and engineering expertise in Africa. Sola grows businesses, connects communities, and helps people prosper by advancing the adoption of clean energy throughout the African continent. For more information visit www.sola.africa