While we wait for the covid-19 virus to run its course the climate change debate has largely been pushed off the mainstream media radar. Other than before and after photos of clearer skies and waterways, the virus-initiated environmental reprieve has illustrated one thing: it shows what might be if we can achieve decarbonisation goals over the next 30 years.

But the economic Armageddon brought about by covid-19 is not sustainable and the world needs to grasp economically, socially and environmentally sustainable ways to decarbonise our economies if we are to achieve internationally collective climate change response goals.

Green hydrogen has been put forward along with EV battery-powered vehicles as a way to decarbonise transport in all its forms, where the sector contributes 22% of emissions.

There are strengths and weaknesses for both. In the passenger car market both energy forms are in the starting blocks but it is unclear who will come out the winner.

In many ways hydrogen-powered fuel cells re-energizing batteries could be the elegant answer for range to add to battery EV’s performance credentials.

However, one feels that this is another Sony Beta vs VHS video moment. The first to be seen to be the leader will draw the massive investment into the retail distribution networks required, be it hydrogen refueling stations or EV charging facilities and the designing of vehicles that need these power sources.

Batteries and hydrogen are both too expensive at the moment, as are the cars that use these power trains. The winner will be the first who can drive savings from material economies of scale.

Ripe for conversion

While I would not be so brave as to pick a winner in relation to passenger vehicle applications there is a clear winner in relation to one very large subsection of industrial transport. Mine site vehicles.

One large scale dump truck, depending on the haul road it is using, will use between 100 and 140 litres of diesel per 100km. These vehicles operate all day every day except for maintenance down time. That’s between 260kg and 360kg of CO₂ per 100km per truck.

Large open pit mines have tens of these vehicles operating continuously, so the numbers build up very quickly.

Replacing diesel with green hydrogen in these applications makes perfect sense:

• The high energy density of H₂ lends itself to transport applications requiring a heavy transport task over distance.
• Quick refuel times similar to diesel.
• Distribution infrastructure on site sized and designed to a captive off-taker/end user.
• Wind and solar farms can be located adjacent to remote mine sites, removing many of the difficult hydrogen transport issues. (Diesel is trucked in from the nearest oil refinery!)
• These large dump trucks are diesel/electric. Diesel is burnt to create electrical power to drive the transmission. Truck modifications would require engine replacement with fuel cells to provide equivalent power. Fuel cells would require significantly less maintenance than diesel engines.
• Hydrogen is significantly more efficient at converting its contained heat energy into mechanical energy at between 60% and 64% verses diesel at 40%.

First movers

It is little wonder that the world’s largest mining companies are embracing green hydrogen as the chosen fuel to help reduce carbon footprints. Anglo American in conjunction with Engie will be trialling a hydrogen-powered dump truck at their Mogalakwena open pit platinum mine in South Africa this year.

The vehicle, which is called a fuel cell electric vehicle (FCEV) haul truck, will be powered by a hydrogen fuel cell module paired with Williams Advanced Engineering’s scalable high-power modular lithium-ion battery system. Williams provides batteries for FIA’s E-Formula motorsport.

This arrangement will replace the existing vehicle’s diesel engine, delivering in excess of 1MWh of energy storage. The battery system will be capable of recovering energy through regenerative braking as the haul truck travels downhill.

Anglo American expects operational performance of the converted trucks to be the same or better than the original diesel trucks, with the additional benefits of cleaner air, less noise and lower maintenance costs.

Furthermore, on March 18 global mining companies BHP, Fortescue Metals and Anglo American and engineering consultancy firm Hatch announced a collaboration on a new green hydrogen consortium aiming to accelerate the production of renewable hydrogen with an initial focus on Western Australia with its rich solar and mineral resources.

With the major mining companies focusing on making significant strides in decarbonisation by 2030 expect there to be more announcements such as this focusing this “low hanging fruit” for the mining industry’s to materially reduce its carbon foot print.

David Paull is a director of the South Gobi Renewables Project, which is looking to develop a green hydrogen production capability based on southern Mongolia’s wind and solar resources.