The world relies on energy to power industry, move people and products, and keep us safe and comfortable. Scientists and engineers are pursuing many pathways to clean and sustain energy systems. One of the most promising solutions is a system using hydrogen and electricity as primary energy carriers. The simplest element, hydrogen, has the potential to provide all of our energy services with little or no impact on the environment, both locally and globally. It can be made from domestic resources, offering opportunities for energy independence. Hydrogen can be used in many applications that currently use more familiar hydrocarbon fuels.
Hydrogen is an energy carrier, in the same way that electricity is an energy carrier. Both can provide energy services to meet our needs. Like electricity, hydrogen can be produced from many sources, including fossil fuels, renewable resources, and nuclear energy. Unlike electricity, hydrogen can be stored for long periods of time. This characteristic is important, especially when we consider storage of large amounts of renewable energy, and distribution of large quantities of hydrogen from one region to another. If hydrogen is to be considered as an energy carrier on a par with electricity, we will need to develop and commercialize a number of hydrogen production, storage, delivery and end‐use processes, and products.