Yellow hydrogen is only as clean as the grid it runs on

Yellow hydrogen has become the world’s most mysterious energy source, perhaps even the most ambiguous. Hydrogen is renowned for its suitability as an alternative to traditional fossil fuels and greenhouse gas emitters, yet not all hydrogen is as eco-friendly as one would have thought. Many companies opt for hydrogen with atomic number 1 to decarbonize their processes, as the main benefit of hydrogen is its low carbon dioxide emissions. Even so, yellow hydrogen tends to be more polluting, but not in all cases.

Yellow hydrogen is seen as the world’s most mysterious energy source

For those who did not know, yes, there is such a thing as yellow hydrogen, but no, it is not as feasible as a fuel. Yellow hydrogen is produced by a process called electrolysis. Electrolysis is when energy is utilized to split water into its elements: hydrogen and oxygen. The energy used during electrolysis is electricity obtained directly from the power grid.

The resulting hydrogen will be as “clean” as the source of the electricity used, which varies from one country to another. In simple terms, if renewable energy sources are used for electrolysis, then hydrogen would be classified as clean or sustainable. Renewable energy sources include solar, wind, hydro, geothermal, and biomass energy. These energy sources are all renewable and sustainable. The type of electrolysis technology also influences the current efficiency.

Yellow hydrogen is polluting under these circumstances

Not all countries have a primary electricity grid that uses renewable energy sources such as solar or wind energy. Spain is a good example of such a country. Per Huffington Post, as of 2021, only 46% of Spain’s electricity was produced by renewable energy sources. Spain’s electricity was primarily produced by natural gas and nuclear energy. This means that hydrogen produced through electrolysis in Spain results in greenhouse gas emissions, making Spain’s primary electricity grid much less sustainable.

In contrast, countries like Norway have primary electricity grids that rely 100% on renewable energy sources. According to Energifakte Norge, Norway’s electricity is primarily produced by hydropower. In addition, Norway’s electricity is also produced by wind, bioenergy, and gas power. This results in the production of hydrogen that is almost 100% greenhouse gas emission-free. Can you see why yellow hydrogen is the most mysterious energy source? It may have its limitations, but only temporarily, we’re sure.

The influence of yellow hydrogen on current efficiency

Primary electricity grids are becoming more sustainable in some countries than in others. Current efficiencies will also depend on the electrolysis technology that is utilized. Current efficiencies range between 70% and 80%. Experts have forecasted that efficiency levels could reach up to 85% by 2030.

Considering the current efficiency range, you will require between 49.2 kWh and 56.3 kWh of electrical energy to produce 1kg of hydrogen. Per Huffington Post, that would mean that the price of 1kg of hydrogen in Spain would vary between €12.46 and €14.24, because the cost of electricity in 2021 was €0.253/kWh.

Nonetheless, these estimated hydrogen costs remain rough numbers and merely indicate the reliance of hydrogen cost on the electricity price. When capital costs become part of the equation, these numbers will certainly look a bit different.

While some may wonder which color might be the new black, others might wonder whether yellow is the new green. To answer that question, under certain conditions, yellow is the new green, depending on each country’s primary source for its electricity grid, as this determines the hydrogen’s sustainability levels. This makes yellow hydrogen most mysterious and most ambiguous. As hydrogen still has many unknowns to us, one thing remains certain. The quest for sustainable fuels continues, and one of these days we will be living a very different life.