A hydrogen economy has long been promoted as a ground-breaking aspect of a low-carbon future. However, there is little consensus on what this future entails, with some overly concerned about lack of demand and others disregarding hydrogen’s limitations. Here, we fill the need for a comprehensive definition of the ‘hydrogen economy’ and illustrate a vision in which hydrogen will primarily be used for decarbonization where no alternative exists. We propose a three-phase implementation plan for hydrogen into the industrial sector as a chemical feedstock, the transportation sector for long-range, heavy-duty vehicles, the buildings sector for heat, and the power sector for seasonal storage. We find that hydrogen will not be the largest energy economy, but with a projected need of 2.3 Gt H₂ annually, it can decarbonize around 18% of energy-related sectors. In the long-term, hydrogen can complement renewable electricity and be the keystone to a 100% renewable future.

长期以来，氢经济一直被认为是低碳未来的一个开创性方面。然而，对于这个未来需要什么，几乎没有达成共识，一些人过度担心需求不足，而另一些人则无视氢的局限性。在这里，我们满足了对“氢经济”的全面定义的需求，并说明了一种愿景，其中氢将主要用于没有替代品的脱碳。我们提出了一个三阶段实施计划，将氢作为化学原料进入工业部门、远程重型车辆的运输部门、供热的建筑部门和用于季节性储存的电力部门。我们发现氢不会成为最大的能源经济体，但预计需要 2.3 Gt H ₂每年，它可以使大约 18% 的能源相关部门脱碳。从长远来看，氢可以补充可再生电力，并成为 100% 可再生未来的基石。