Number of policy instruments in the hydrogen sector by instrument type. The R&D category entails those instruments promoting hydrogen research and development either through tax incentives or grants/subsidies; the Investment category comprehends those instruments promoting the investment in hydrogen production, usage, and/or transport and storage infrastructure; International Initiatives entail the instruments that have an international component i.e. treaties, accords, diplomatic activities, investments made by the Government abroad; Economy-wide instruments refer to non-sector-specific policies that provide a relative advantage to climate-friendly products and economic activities; Network/cluster promotion encompasses those policy instruments focused on building regional clusters and/or networks; Education and information entail the instruments to increase public awareness related to hydrogen; Voluntary agreements refer to those agreements made with private entities to take certain actions without an enforcement mechanism by the government.

Number of policy instruments targeting hydrogen storage and transport infrastructure distributed by its subcategories: mode of transport: road, pipeline, maritime or unspecified, and storage. "Multiple" refers to interventions that touch on different modes of transport and/or transport and storage infrastructure at the same time. These subcategories encompass not only the instruments directly affecting transport and storage infrastructure in the graph „Policy Instruments by segment of the hydrogen value chain“, but also the transport and storage infrastructure-relevant policy instruments that are accounted for under the category “Multiple” of the previous figure i.e., that also touch on different parts of the hydrogen value chain in addition to transport and storage infrastructure. The latter needs to be included here for an accurate representation of policy instruments targeting hydrogen transport and storage infrastructure.

Number of policy instruments that target hydrogen usage in the transport/mobility sector distributed by its further subcategories: passenger vehicles, buses, rail, trucks, aviation, maritime, unspecified, and multiple (touching on two or more subcategories within transport/mobility). These subcategories encompass not only the instruments directly affecting usage in the graph „Policy Instruments by segment of the hydrogen value chain“, but also the usage-relevant policy instruments that are accounted for under the category “Multiple” of the previous figure i.e., that also touch on different parts of the hydrogen value chain in addition to usage. The latter needs to be included here for an accurate representation of policy instruments targeting hydrogen usage and more specifically, use in transport/mobility.