Hydrogen is fast becoming one of the leading options for storing energy from renewables. Little wonder it featured in a couple of emissions reduction pledges at the COP26 as a means of decarbonizing heavy emitting industries.
This increasing interest in hydrogen can be linked to the fact that it can be produced from various resources like natural gas and nuclear power as well as from renewable energy like solar, wind, and biogas. However, its environmental impact and energy efficiency depend on how it is produced.
Hydrogen can be blue, green, or grey (and sometimes yellow, turquoise, or pink) depending on production methods but for the sake of the environment and reaching net-zero by 2050, we’ll be spotlighting green hydrogen and why it is relevant in today’s emissions target conversations.
You see, green hydrogen, of all the varying colors of hydrogen, is the only type of hydrogen that is produced in a climate-neutral way.
It is produced when renewable electricity is used to power an electrolyzer that splits water into hydrogen and oxygen. This process produces pure hydrogen with no harmful by-products.
Green hydrogen can also redirect excess electricity which is hard to store in renewables like excess wind power, to electrolysis, harnessing it for the creation of hydrogen gas stored which can be stored for future energy use.
However, this is different from the production methods of grey hydrogen and blue hydrogen.
For one, grey hydrogen is normally produced by splitting methane with steam into carbon dioxide (a major climate change driver) and hydrogen. This is the most common method for producing bulk hydrogen and accounts for most of the global production.
Grey hydrogen is also produced from coal, with a higher carbon emission per unit of hydrogen produced, earning it an alternative name – brown or black hydrogen.
On the other hand, blue hydrogen, though similar to grey hydrogen in terms of production method, uses additional technologies to capture the carbon dioxide produced when hydrogen is split from methane and store it for future use.
One can see from the above that grey and blue hydrogens are out of the climate conversation and that we will need green hydrogen to reach net-zero emissions, especially in heavy industries, shipping, and aviation.
Green hydrogen is an ideal solution and a great win for climate action as it emits only water when burned but its creation process can be carbon-intensive. This is not surprising as the renewable energy capacity that is needed to produce and scale hydrogen (and make it less carbon-intensive) continues to drag behind.
According to a report, green hydrogen (and blue hydrogen) account for less than 1% of global hydrogen production, with grey hydrogen accounting for the remaining 99%.
As Africa’s electricity needs increase, renewable energy capacity needs to be increased to convert water into hydrogen to meet these needs. The good thing is that some African countries are keying into green hydrogen production.
For example, Namibia, with some of the best wind and solar resources in the world as well as vast land, has set out a policy decision to position the country as a green hydrogen production and distribution hub for Europe and the rest of the world.
Another example is the Tunisian-German Alliance for Green Hydrogen that was concluded by Tunisia in an agreement with Germany in 2020.
The hydrogen landscape in Africa looks promising. What’s in it for Africa when countries invest in this sector? Well, we’ve highlighted the pros and cons of hydrogen and what African countries are doing to tap into the possibilities it provides. Only time will tell what the possible outcomes will be.
