Zero-emission hydrogen will play a very important role in the energy system of the future. Hydrogen and its derivatives (e.g. methane, ammonia and methanol) can store energy. They can be transported over long distances and have many different uses. “Green hydrogen” can thus help to prevent greenhouse gas emissions, especially in areas where direct electrification is not possible, such as steelmaking, parts of the chemical industry and shipping.

There are high hopes that hydrogen can contribute to net zero lifestyles and economic activity. In this “In a Nutshell” edition, the Academies’ Project “Energy Systems of the Future” (ESYS) outlines the basic facts about hydrogen and explores its potential future uses.

The publication explains that although hydrogen is already used in industry, demand is set to grow strongly over the next few decades. Zero-emission hydrogen can play a key part in the energy transition. For this to happen, however, a number of barriers must still be overcome, and targeted decisions must be taken. Since the groundwork for a hydrogen economy is already being laid today, close coordination within Europe is essential.

The key questions include the following:

• What are the different methods of producing hydrogen and how do they differ in terms of CO2 emissions, water usage and costs?
• Where could hydrogen be used instead of fossil fuels in the future, and where do more efficient alternatives exist?
• What role will hydrogen imports play?
• What infrastructure will need to be built?
• What are the transport options?