The potential role of hydrogen in energy systems with and without climate policy

Introduction of hydrogen in global energy system can lead to lower CO2 emissions (high end-use efficiency; low-carbon production of hydrogen) but might also increase CO2 emissions (producing hydrogen from coal). We used the long-term energy model TIMER 2.0, to study the use and production of hydrogen and its influence on global CO2 emissions. This is done using a set of scenarios with assumptions on technology development, infrastructural barriers and climate policy (CP). We found that even under optimistic assumptions hydrogen plays a minor role in the global energy system until the mid-21st century due to the system inertia—but could become a dominant secondary energy carrier in the second half of the century. Hydrogen is mainly produced from coal and natural gas. Hence, hydrogen-rich scenarios without climate policy increase CO2 emissions up to 15% by 2100 compared to the baseline. However, if climate policy is assumed, CO2 from fossil feedstock-based hydrogen production is captured and sequestrated, which indicates that an energy system that includes hydrogen is much more flexible in responding to climate policy.