Do you think green hydrogen will save you? Think again!

In the context of addressing climate change, comprehending the intricacies and ramifications of various energy sources emerges as crucial. Alas, delving into alternative fuels, particularly hydrogen, reveals a range of complexities, spanning production methods, environmental impacts, and economic factors.

LNG: Key considerations

Starting with LNG, it is widely known by now that natural gas, when emitted unburned into the atmosphere, is 86 times worse than CO2 due to methane’s potency as a greenhouse gas.

In the last 300 years, atmospheric CO2 increased by 50%, whereas methane increased by 250%. This means methane increases in the atmosphere five times faster than CO2 and does 86 times the damage over a 20-year period.

Alternative fuels: Are they really green?

The focus it now shifted to alternative fuels, starting with gray hydrogen. It is called gray hydrogen because it comes from natural gas, which accounts for 70% of the hydrogen produced today. About 27% of hydrogen is produced from coal, and only 3% from electrolysis, with just 1% being green hydrogen.

This means only 1% of electrolysis-produced hydrogen uses renewable electricity and thus is green. Producing hydrogen via electrolysis requires substantial electricity—55 kilowatt hours for every kilogram of hydrogen produced. If this electricity comes from a typical city grid, it emits 49 kg of CO2 for every kilogram of hydrogen produced.

Ammonia, derived from gray hydrogen, is called gray ammonia. To produce ammonia, nitrogen is added to hydrogen. This nitrogen is obtained by oxidizing the air—essentially burning the oxygen in the air to isolate nitrogen. Once the nitrogen is isolated, it is added to hydrogen to produce ammonia.

Methanol production also largely relies on natural gas, emitting 12 kg of CO2 per kilogram of methanol produced.

The many shapes and forms of hydrogen

Currently, global hydrogen production is 87 million tons per year, which is relatively low. As most of this hydrogen comes from natural gas, resulting in annual CO2 emissions of 830 million tons—ironically, it reaches the same amount emitted by the shipping industry per year, when burning 250 million tons of fossil fuels.

Economic considerations for alternative fuels: Bunkering infrastructure

Furthermore, transitioning to green hydrogen or ammonia would require replacing existing bunkering infrastructure at a total cost of $9.5 trillion, significantly more than the current infrastructure cost of $2.5 trillion. To put this into perspective, all the ships in the world are valued at $1.5 trillion.

The only fuel that can utilize existing infrastructure is methanol, which can even be retrofitted to burn in current engines. However, green methanol production involves green hydrogen combined with CO2, a costly and complex process, making it more expensive than ammonia.

Can green hydrogen and the green fuels produced from it (green ammonia, green methanol) save us?

Here’s the breaking news: hydrogen, whether green or not, is a powerful, indirect greenhouse gas.

Studies before 2020 estimated hydrogen to be 10-12 times worse than CO2, but recent studies suggest it is 60-200 times worse. Hydrogen works in three ways to superheat the atmosphere:

#1 When hydrogen escapes into the atmosphere unburned

When hydrogen escapes into the atmosphere unburned, it binds with hydroxyl free radicals, preventing methane from binding with these same radicals , thus methane remains potent in the atmosphere longer.

As time passes, the potency of methane decreases. The first five years it’s 120 times worse than CO2. In a hundred years it will be 28-30 times worse, because methane binds with hydroxyl and it’s not methane anymore.

#2 Through ozone production

Additionally, hydrogen reactions produce ozone in the troposphere and water vapor in the stratosphere, both of which are greenhouse gases. A recent study published in the high-impact journal “Atmospheric Chemistry and Physics” reports that hydrogen’s indirect warming potency per unit mass is around 200 times that of CO2.

“Converting hydrogen’s full atmospheric radiative efficiencies to per unit mass and comparing it to the radiative efficiencies of CO2 and methane shows that hydrogen’s indirect warming potency per unit mass is around 200 times that of carbon dioxide and larger than that of methane.”

#3 Through massive leakage and energy loss

Considering hydrogen is the smallest molecule in the universe  (eight times smaller than methane), it leaks easily during electrolysis, compression, storage, and so on. It even slips through the steel walls of containers and pipes. Estimates of hydrogen leakage vary, but some experts suggest it could be as high as 20%.

Current hydrogen production is 87 million tons per year, but transitioning to a hydrogen economy could require up to 2 billion tons annually by 2050. Assuming only a 10% leakage rate, this would result in a 0.4°C temperature increase instead of a decrease.

The realistic path to decarbonization

In conclusion, we are proceeding on the wrong path at a tremendous cost to society. While addressing global warming is essential, pretending that the chosen solution is better than our current practices is, in my view, criminal for both the environment and the global economy. To truly decarbonize, we need new technologies, such as fourth-generation nuclear power and advanced batteries with large storage capacities.

The views presented are only those of the author and do not necessarily reflect those of SAFETY4SEA and are for information sharing and discussion purposes only.

Above article has been edited from Panos Zachariadis’ presentation during the 2024 GREEN4SEA Athens Forum.

Explore more by watching his video presentation here below