By Dr Nicolaas C Steenkamp
Hydrogen is considered a potential power source of the future, but what risks are associated with it?
The mining sector has been investigating different power sources for operational and mobile equipment utilisation. The two main contenders are Battery Electric Vehicles (BEVs) and Hydrogen Cell technologies. There are advantages and disadvantages associated with both and the risks and limitations of hydrogen as an option are considered here.
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The main drawbacks for establishing hydrogen power generation at mine sites are, first off, that it is still an expensive form of power generation. Acceptable range requires extremely high-pressure and on-board hydrogen storage. Currently there are also very few places that are equipped to establish refuelling capacity. If the hydrogen cannot be produced on site, it is expensive to transport and there is no piping or pumping infrastructure in place yet that can safely transport the product over long distances.
The main risk related to the use of hydrogen at any operation is the fact that it is a highly flammable substance. Hydrogen is also colourless and odourless, making it extremely hard to detect during a leak. This requires extreme safety measures to be applied at all times, high costs associated with regular inspections and maintenance of the infrastructure as well as ensuring that all staff tasked with working in or around the hydrogen storage or distribution are sufficiently trained. Another risk is the storage of hydrogen as ammonia.
Although there is a continuous race between hydrogen and BEV systems to improve performance, trials to date have indicated that hydrogen systems are less effective when compared to BEV systems, especially in the mining environment. Hydrogen powered haul trucks have, however, been adopted by a number of mining operations during the course of last year.
In 2022, a notable volume of hydrogen was still considered to be “grey ”, rather than “green” due to the fact that it was generated using non-renewable energy and incurred high transport emissions. The production of hydrogen is also a very water-usage-intensive process, which may not make it a viable long-term solution for regions with water constraints or during periods of drought. Provisional research has also indicated that the use and generation of hydrogen may contribute to global warming conditions.
The scale-up of hydrogen as an energy alternative is also challenged by various factors such as: production costs, land availability for generation and storage of the hydrogen, the construction or repurposing of infrastructure to switch to hydrogen power and evolving technologies, which may not be compatible. The last challenge is the pressing matter of storage of a volatile gas like hydrogen, and finally the storage of hydrogen and the energy it generates.
The use of hydrogen power is still in its infancy, and it is anticipated that the coming decade will see improvement in the use of hydrogen and reduction in the risk associated with it.