Sensitivities

The potential of solar PV, onshore and offshore wind is increased in order to test how much variable renewable energy sources could be integrated into the optimal Belgian energy system. The full potential of onshore wind (9.3 GW) and offshore wind (20.5 GW) is deployed, but not the full potential of solar PV, as in the Base Case. Consequently more hydrogen is produced from offshore wind and less gas is used to produce electricity. Most hydrogen remains imported because green electricity is preferably used directly for final electricity demand.

The average distance of offshore wind farms to the coast is artificially increased to detect when it is more interesting to produce hydrogen offshore rather than bringing electricity. As transporting hydrogen is cheaper than transporting electricity, with the distance increasing, the hydrogen production offshore also increases until it becomes more expensive than hydrogen imports from the COASTAL cluster.

The Base Case assumes a net-zero energy system by 2050. But the Belgian energy system is integrated within the European energy market and the decarbonisation cost may be different across neighbouring countries. Therefore, some countries may have net-positive emissions, while other countries have net-negative emissions, in an optimal EU-wide energy system that still achieves net-zero emissions. If some CO₂ emissions are allowed for Belgium in 2050, the optimal energy system in Belgium is cheaper and less CO₂ is captured and exported.

Hydrogen can be produced in Belgium by electrolysis (green hydrogen) or using Steam Methane Reforming (SMR), or imported. There is a trade-off between imports and domestic production, depending on the respective prices. If the H₂ import cost increases, more H₂ is produced in Belgium, but the limited renewable electricity potential and the CO₂ export constraint restrict the production green electricity and force the hydrogen system to be balanced with blue hydrogen production from SMRs and green methane imports. This increases the need for carbon capture capacity and CO₂ exports.

The capacity to export CO₂ by pipeline strongly impacts the ability to use methane in Belgium’s net-zero energy system in 2050. When the CO₂ export capacity decreases, less CO₂ emissions is allowed, so that CCGTs are less used and more electricity is imported. In the extreme case shown above, no CO₂ can be exported, CCGTs are seldom used and the captured CO₂ is even used in methanation facilities to produced CH₄ needed for final demand.