Sector coupling strategies by increasing the use of renewable power in other sectors
Hydrogen can be used to couple renewable electricity with other energy use sectors as depicted in Figure. Some of the applications of hydrogen are listed below.
As Figure illustrates, hydrogen contributes to “sector coupling” – on the one hand between the power system and on the other between the industrial, buildings and transport sectors.
Sector coupling creates extra loads that represent new markets for hydrogen produced from VRE sources, furthering the integration of high shares of VRE in the power system.
Well-defined safety standards, appropriate ventilation and leak detection are required to ensure safe operations with hydrogen. It is a highly flammable gas and can burn at a wide range of concentrations.
The US National Fire Protection Association gives hydrogen a 4, the highest flammability rating, denoting materials “that completely vaporise at normal pressure and temperature and burn readily”.
These standards already exist for various industrial applications, but they may need to be streamlined considering emerging new applications of hydrogen, for example as a fuel for cars.
Some of the applications are listed below:
Hydrogen can be used as feedstock in the chemical industry. It is a key input to the production of ammonia, synthetic fuels and various types of fertiliser. It can also be used in the methanation process to produce methane from CO₂. Hydrogen is also used to produce synthetic liquid fuels from biomass, which increases the efficiency of biomass utilisation significantly. Hydrogen can also be used to replace fossil fuels and act as a reducing agent in heavy industries such as steel. In Sweden, for instance, the HYBRIT project aims to replace coking coal with hydrogen in the ore-based steelmaking process.
Hydrogen can provide power using fuel cells. For example, Europe hosts 95 hydrogen stations where a fuel cell can be refuelled in three minutes for a range of 500–800 kilometres (H₂ live, 2019). Another way to use hydrogen as a fuel is to blend it with natural gas in the existing natural gas pipelines.
Standards suggest blending up to 10% hydrogen (by volume), with a potential to increase it to 20% (Hydrogen Strategy Group, 2018) (NREL, 2015) (IRENA, 2018a). However, the appropriate blend may vary significantly between pipeline network systems and natural gas compositions and must therefore be assessed on a case-by case basis (NREL, 2013; ARENA, 2018). The current limit on hydrogen in gas turbines and engines should be increased in the near feature.