EPISODE 02
The Basics of Hydrogen and the Colors of Hydrogen

Understanding Hydrogen: The Element Shaping Our Energy Future

An interview with Dr. Lydia Maketo from the Redefine H2E Team

Hydrogen has the potential to transform our energy systems, offering a pathway away from fossil fuels and towards a sustainable future. But what exactly is hydrogen, how is it produced, and why does its “color” matter for our climate goals?

In the latest episode of Redefine H2E, Dr. Lydia Maketo one of our guest researchers at the Technical University of Munich unpacks these questions.

Why Hydrogen Matters

Lydia Maketo:

Hydrogen is the most abundant element in the universe, but on Earth, it doesn’t exist freely in its pure form. It’s always bound to other elements, like in water or hydrocarbons. To use it as an energy carrier, we first need to extract it.

Once produced, hydrogen can fuel vehicles, power industrial processes, and store renewable energy. Crucially, hydrogen can be converted back into electricity in fuel cells, producing only water as a byproduct, making it a clean energy carrier—if produced sustainably.

How Hydrogen is Produced: The Color Code

Not all hydrogen is created equal, and the production method determines its climate impact. 

The main types:

• Green Hydrogen is produced via electrolysis using renewable electricity, making it completely CO₂-free.

• Blue Hydrogen comes from natural gas but uses carbon capture and storage (CCS) to reduce emissions.

• Gray Hydrogen, the most common today, is also produced from natural gas but without CCS, emitting significant CO₂.

• Turquoise Hydrogen is made through methane pyrolysis, producing solid carbon instead of CO₂, with sustainability depending on the energy source.

Lydia Maketo:

Green hydrogen is the gold standard, but it’s currently more expensive than fossil-based alternatives. Our challenge is to scale up green hydrogen production while reducing costs, making it accessible for global energy needs.

Hydrogen: A Key Player in the Energy Transition

Hydrogen’s versatility allows it to be used in fuel cells for transport, burned in industrial furnaces, or stored for later use when renewable energy supply is high. Its high energy density per unit mass makes it especially attractive for sectors like heavy industry and long-haul transport.

Lydia Maketo:

Hydrogen has been part of industrial processes for decades, but its potential as a clean energy solution is what makes it truly exciting for the future.

Moving Forward

As the Redefine H2E team continues to explore hydrogen’s role in achieving climate goals, understanding the basics is a crucial first step. The color of hydrogen matters because it tells us about its sustainability. If we want hydrogen to help us reach net zero, we need to prioritize green hydrogen production globally.