Farai Chireshe, Tjasa Bole-Rentel and Saliem Fakir contend that a key argument in favour of producing ‘green’ hydrogen in South Africa is that the renewable electricity required for its production does not carry the political burden that weighs on the electricity sector
Mining companies are embracing the hydrogen era. The availability of sufficient strategic minerals for batteries is not limitless, but if you can produce oxygen and hydrogen cheaply, the magic of hydrogen power will explode as an unstoppable energy revolution whose potential extends beyond the automotive sector.
To meet the climate goals of the Paris Agreement, we should also focus on how to decarbonise other sectors, such as long-distance and heavy-duty transport, chemicals and minerals processing. Hydrogen presents many opportunities to do just this.
Currently, hydrogen is mostly used in petrochemicals refining to produce fuels and chemicals, and in fertiliser manufacture. Most of this hydrogen is produced unsustainably from nonrenewables like natural gas, coal and oil. While sustainable – or ‘green’ – hydrogen can be produced from bio-based feedstock and wastes using similar processes to fossil-derived hydrogen, the greatest potential is through electrolysis of water using renewable electricity.
South Africa has vast wind and solar potential, able to supply the country’s electricity requirements many times over. Therefore, even if our electricity mix were to be composed entirely of renewables, there would still be plenty of renewable electricity available for hydrogen production.
An important use of hydrogen in a low-carbon economy is as an energy carrier for energy storage. This is key, considering the intermittency of wind and solar power. When there is surplus electricity, the excess power can be used to generate hydrogen. This can not only help to stabilise the grid and reduce the need for curtailment of renewable electricity generation during surplus generation – crucially, it makes it possible to fill the gaps when generation is lower than demand.
Substituting fossil-fuel-derived hydrogen with green hydrogen in petrochemicals refineries can significantly lower Scope 1 emissions from these industries. In refining, hydrogen is used as an ingredient to ‘fine-tune’ the petroleum products to the required quality. Most of the emissions from the largest single-point greenhouse-gas (GHG) source in the world – Sasol’s Secunda plant – are process emissions related to hydrogen production. Substituting green hydrogen in this process would result in GHG savings of about 4 t of carbon dioxide (CO2) for every ton of liquid product.
Current studies are exploring the potential of hydrogen as a substitute for coking coal in the reduction of iron-ore in steelmaking. Using coal to reduce iron produces carbon monoxide, which is typically combusted, producing CO2, a GHG. If hydrogen is used as the reducing agent, the process will, essentially, be emission free, since the only by-product will be water. In Germany, one of the world’s largest steel producers, ArcelorMittal, plans to build a pilot plant using such technology. This is an opportunity to decarbonise the steel sector, which accounts for up to 9% of global carbon emissions. Successful trials in Germany could result in similar projects at ArcelorMittal’s South African operations.
One of the most publicised uses of renewable hydrogen is in powering fuel cells, which convert the chemical energy of a hydrogen carrier – such as hydrogen, ammonia, methanol or ethanol – directly into electrical energy. Fuel cell technology can be used to produce electricity for various purposes, but the most documented opportunity is its use in fuel cell electric vehicles (FCEVs).
FCEVs are generally less efficient than battery electric vehicles (BEVs), owing to the high energy consumption associated with water electrolysis for the production of hydrogen. Yet, in spite of the lower efficiencies, it takes a much shorter time to refuel a hydrogen tank than to recharge a battery.
Additionally, while the kilometre range of BEVs has been improving steadily, they still fall short, compared with FCEVs. This makes fuel cells the most suitable clean energy system for heavy-duty and long-distance transport options in the short term.
In Germany, hydrogen-powered trains are replacing diesel trains where there is no electricity infrastructure and brewing giant AB InBev plans to acquire 800 hydrogen-powered trucks to transport beer. Recent studies have also evaluated the feasibility of using ammonium produced from ‘green’ hydrogen as a marine fuel to decarbonise shipping.
Common alcohols like ethanol and methanol can also be used as a hydrogen source in FCEVs. The advantage of using liquids in FCEVs is they are easier to handle than hydrogen in the form of high-pressure gas. The recent publication of the Biofuel Regulatory Framework should result in the development of distribution systems for ethanol, which should make the transition to ethanol FCEVs easier, as is the case in Brazil. The demand for bioethanol arising from the use of ethanol FCEVs could also help to diversify the struggling sugar industry.
The link between hydrogen and fuel cell technologies and platinum-group metals (PGMs) is crucial in the South African context. Platinum catalysts are critical components of fuel cells and the electrolysers that produce hydrogen from water. This presents a significant commercial opportunity for South Africa, which mines over 70 % of the world’s platinum. Extensive PGM mining could boost the industry and offset the jobs losses associated with declining coal mining. Replacing diesel-powered trucks with full cell trucks in mining is also a critical element of the path towards the decarbonisation of the mining sector.
Using locally produced FCEVs and locally sourced hydrogen will strengthen South Africa’s energy security and impact positively on the trade balance by reducing the need for energy imports (fuel and technology). Additionally, Far East countries Japan, China and South Korea are big proponents of hydrogen FCEVs, and there is a huge commercial opportunity for South Africa to supply hydrogen to meet the large demand in these countries by 2030. Other economic benefits include the creation of new jobs, for example, at the fuel cell factory planned for Durban.
There is also a link to economic growth within the region. Lithium and cobalt are critical components of electric vehicle batteries and Zimbabwe and the Democratic Republic of Congo have vast deposits of these minerals. If the governance and sustainability of mining in those countries could be improved, this would represent an important opportunity for their mining sectors.
The key hindrance to fuel cell technology thus far has been its high price tag. However, with the cost of renewables dropping rapidly, fuel cell technologies are becoming cheaper. A key argument in favour of producing green hydrogen in South Africa is that the renewable electricity needed for its production does not carry the political and ideological burden that falls upon the electricity sector.
Using our vast renewable resources to produce green hydrogen for domestic use or export does not threaten established business models or vested interests. Localising technology for renewable power on the back of green hydrogen production will also make our grid-connected renewable power cheaper.