Page 64 - Energize August 2022

TECHNICAL

The key advantage of hydrogen over other potential and surface mine transport vehicles has been established as
energy storage options is its ability to discharge energy over a viable and a number of mining companies are planning to move
2
longer time period compared with other options, making it an in this direction, as well as establish solar/FC/H operations to
appropriate option for energy supply system backup for medium- provide power to the mines.
to-large-scale power systems that are islanded from main grids. In South Africa the first step in this direction has been taken
Surplus energy from the RE system can be used by the by Anglo American with the introduction of a FC/battery hybrid-
electrolyser to generate hydrogen that can be used to meet driven mine truck at the Mogalakwena Mine. The hybrid power
the other energy requirements of the mine, such as mine plant has a capacity of 2 MW. Hydrogen for the truck is provided
vehicles and traction systems, as well as a source of heat. The FC by a 3,65 MW electrolyser powered by a PV array. The mine
produces heat that could be used directly by the mine or could already features a 100+ MW solar array, which provides power
be stored in thermal storage for later use. for the mine operation, and will eventually be used to produce
Fuel cells are more efficient than IC engines and offer the hydrogen to power the whole fleet and to run fuel cells for a
same or better efficiency than gas turbines when used in the mine’s operations. Anglo American is planning to convert the
CHP mode. A hybrid power system that already incorporates whole mine fleet to hydrogen power.
renewables has the capacity to incorporate “green” hydrogen
production by electrolysis. The common approach today is to References
use “surplus” renewable energy to produce hydrogen, but this 1. H Kalantari, et al: “Hybrid renewable hydrogen energy solution
does not limit the use of purpose-designed renewable hydrogen for application in remote mines”, Energies, December 2020.
production plant. Hydrogen storage is much easier and cheaper 2. P Valicek: “Fuel cell technology in underground mining”,
than battery storage and long storage periods are possible. SAIMM, 2014.
3. M Lin: “Anglo American launches hybrid hydrogen-battery
The way forward mine haul truck in South Africa”, Clean energy news, May
There are several pilot PV/E/FC hybrid systems in operation 2022.
world-wide and results are promising.
The use of hybrid FC/battery fuel cells to power underground Send your comments to rogerl@nowmedia.co.za

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