Hydrogen is unmistakably a colourless gas. So why is it regularly spoken of in a myriad of different colours? The ironic naming convention for hydrogen may seem trivial but it has vast implications for how we will create, price and use it as a future fuel in humanity’s quest for net-zero emissions.
A crash course in hydrogen colour coding will lead one to discover that the main colours refer to the different production methods used.
- Green hydrogen is produced through water electrolysis process by employing renewable electricity, such as solar or wind power. The method of electrolysing water (and splitting it into its individual elements) produces no harmful greenhouse gas emissions when powered by renewables.
- Blue hydrogen is sourced from fossil fuels. However, the greenhouse gas emissions are captured and stored underground (via carbon sequestration), categorising this process as carbon neutral
- Grey hydrogen is produced from fossil fuel and commonly uses the steam methane reforming (SMR) method. During this process, greenhouse gas emissions are produced and eventually released into the atmosphere.
- Black or brown hydrogen is produced from coal. The black and brown colours refer to the coal itself – bituminous (black) and lignite (brown). The gasification of coal is a method used to produce hydrogen. However, it is a polluting process with carbon dioxide and carbon monoxide produced as by-products and released into the atmosphere
- Turquoise hydrogen can be extracted by using the thermal splitting of methane via methane pyrolysis. Though at the experimental stage, the process removes the carbon in a solid form instead of CO2 gas.
- Purple hydrogen is made though using nuclear power and heat through combined chemo thermal electrolysis splitting of water.
- Pink hydrogen is generated through the electrolysis of water by using electricity from a nuclear power plant.
- Red hydrogen is produced through the high-temperature catalytic splitting of water using nuclear power thermal as an energy source.
- White hydrogen refers to naturally occurring hydrogen.
In the kaleidoscope of hydrogen colours, only green is a truly clean fuel. Gasified processes may be more effective and faster to produce but over time, their carbon output does little to contribute to net-zero emissions.
The financial modelling also supports the supremacy of green hydrogen. In its infancy, the hydrogen market amounts to about 71 million tonnes per annum, or $US177.3bn ($228.4bn). But looking ahead to 2050, firms such as Goldman Sachs estimate that the market for green hydrogen could be worth $10 trillion globally. Moreover, with accelerated adoption, it could supply up to 25% of the world’s energy needs by that time, making it the fuel of the future.
Aside from the positive impact it has on our climate, green hydrogen production has the potential to become a huge contributor to the Australian economy.
Funding from the Government combined with existing gas exportation infrastructure makes Australia the perfect petri dish for a true hydrogen export market. The first S&P Global assessment of hydrogen pricing shows green hydrogen in South Australia produced using alkaline electrolysis, including capital expenditure, was assessed at $1.9215/kg.
While in Japan, hydrogen made using the same process was assessed at $4.6211/kg. By continuing to drive down the costs associated with producing hydrogen, the industry will be closer to achieving the Government’s goal of getting the price of hydrogen under $2/kg. Under $2/kg, hydrogen becomes competitive with alternatives in large-scale deployment across energy systems.
The opportunity to become a powerhouse in this emerging energy market is enticing and one that Verdant Earth Technologies is already realising. In the past year, we have already secured alliances with The Port of Darwin and The Port of Geelong to store and export green hydrogen produced from our Verdant Energy Hub – Hunter Valley.
The true test for hydrogen will be the willingness of industry heavyweights to overcome the temptations of quick returns and easily modified infrastructure that comes with blue and grey hydrogen. We are at a critical juncture in our energy future – as fossil fuels phase out and solar and wind struggle to meet grid stability requirements, green hydrogen has the potential to be a green investment worth its weight in gold.