Clean energy, green hydrogen and climate change

Professor Earle Taylor
Needless to say, our planet is in dire trouble. And I believe God himself is weeping profusely at how we, the children of His creation, are casual in our stewardship and responses. Today, the evidence of the climate crisis is abundant, real and substantively negative. Not only is it forcing the world to recognise the rapid escalation, it’s giving us a conscious urgency to change course and our behaviours and selfish approaches to our commonwealth – the Earth.

Our dilemma

And here is the predicament. No one, not even our greatest scientific minds, has offered any clue or clear consensus of what to do, how to navigate the transition, how much time we have to make the necessary corrections, or what the outcome will be if we don’t do it in time. Unfortunately, by our own individual acts – greed, lust for power, selfishness and commercial reasons – we are exacerbating the processes to our ultimate collective dismay and demise.

To make some urgent corrections, there are three crucial concerns that we must unambiguously recognise, face and start immediately working on, without delay or bureaucratic procrastination. For ease and practicality, I have identified these as: Green energy transition; the green hydrogen transition; climate (cultural) change; potable water reserves; and food insufficiency.

In the current public conversation and debate on the first three, there exists quite a bit of confusion, misinformation and misperceptions regarding green energy vis-à-vis green hydrogen and climate change.

Green energy

‘Green’ refers to ‘clean’ energy, that is, energy provided by non-traditional sources other than fossil fuels (coal, oil, lignite, and, to a lesser degree, natural gas).

Renewable sources include solar, wind, geothermal, wave-and-water (hydro) power, biomass, and hydrogen. Note here that the ‘non-green’ aspects of fossil fuels come from the pollutants created by their conversion and use when they are flared into the atmosphere and our environment, such as carbon dioxide (CO2), nitrogen oxides (N2O), sulfur dioxide (SO2), and other associated volatile organic compounds (VOCs) and particulates.

Green hydrogen

Every student who passed through primary school knows that hydrogen is one of the two fundamental elements, along with oxygen, that make up water. But hydrogen is only an energy carrier; it is not a direct energy source.

So we must produce green hydrogen from water through the process of electrolysis. This means that we will need to separate oxygen from hydrogen using a clean primary energy source, like solar, photovoltaic, electricity, hydro, etc. Thus, it is the specifics of the production process, including the energy source it uses, that determine whether the resultant hydrogen will be described as green, blue, grey, pink or yellow.

Yellow hydrogen

Had we used nuclear power, for example, as the primary energy source to drive the electrolysis process, we would instead end up with yellow hydrogen.

Note also that in both processes (green and yellow), only hydrogen and oxygen are produced, where we capture and store only the hydrogen and vent the oxygen off into the atmosphere. This flared oxygen has no negative impact on the environment or planet, and hence, we term the energy hydrogen released as ‘green’ and ‘clean’ hydrogen.

Grey hydrogen

Had we used natural gas as the primary source of energy to drive the electrolysis process to separate hydrogen from the CO2 through steam methane reforming (SMR) or auto thermal reforming (ATR) technologies to produce grey hydrogen, we would have been producing grey hydrogen all over the world for more than half a century. In this process, we split natural gas into hydrogen and CO2 (SMR or ATR), where we only capture and store the hydrogen and release the CO2 into the atmosphere, much like smoke.

Blue hydrogen

Similar to grey hydrogen, we produce blue hydrogen from natural gas as the primary energy source to release or separate hydrogen and CO2 using either the SMR or ATR technologies. We capture and store the hydrogen separately and may contain the CO2 or release it into the atmosphere. This hydrogen would be described as blue hydrogen.

Pink hydrogen

The process of producing pink hydrogen is quite similar to that of producing green hydrogen, where the electrolysis process is achieved using a nuclear power source.

The future of fossil fuels

Not discounting the value and relevance of fossil fuels for the next 10 to 15 years or so, it should be noted that the industry has invested significantly over the past two decades to reduce their carbon footprint of carbon monoxide (CO), CO2, nitrous oxide (N2O) and SO2 through new technologies, but to date these efforts have proved to be insufficient.

As we all know, CO and CO2, as expressed in the form of greenhouse gases, act as heat sinks or traps suspended in the atmosphere, causing abnormally high temperatures that hinder land, water, crops, plants and animals from breathing freely and naturally. Excessive CO2 in the atmosphere is the major source of climate change. N2O and SO2 are expressed as smog and acid rain.

Clean energy

On the other hand, clean energy is derived from renewable sources that include solar, wind, geothermal, wave and water power; this energy is not associated with pollutants. Hence, these are described as clean energies. Of course, there are other significant, but not primary, sources of air pollutants that include moveable sources such as cars and planes; fixed sources such as power plants and oil refineries; and human and natural sources such as wildfires, earthquakes, and more.

The climate crisis

The world today is in a state of climate emergency, and all countries, large and small, need to shift into emergency gear if we are to stop the environmental slide and save ourselves from the impending disaster. Every country has a role to play in our collective responsibility to future generations. The climate crisis is already here, and climate change is the reaction. The urgency of our collective response will determine, to a large extent, what happens.

While Namibia’s carbon footprint is relatively small at 3 901 830 tonnes or 1.65 tonnes per capita and ranks 0.01% of the global share, the effects of climate change have been evident for the past one to 20 years, in terms of irregular weather patterns, excessive droughts, heatwaves, veld fires, floods and even periodic earthquakes.