Sustainable energy transition towards self-sufficiency for densely populated regions: the case of Belgium

The energy transition is driven by climate change, emission reduction targets, and the declining cost of renewable energy technologies. This study examines Belgium's transition to a 100% renewable energy system, considering the country's high population density, limited land availability, and high energy use. Specifically, the potential of ocean energy, such as offshore wind power, floating offshore solar photovoltaics, and wave power, is investigated to achieve energy self-sufficiency. Using the EnergyPLAN model for hourly simulations across the power, heat, transport, and industry sectors, the research compares the current system against two 2050 scenarios: full self-sufficiency and e-fuel imports. The results suggest that while self-sufficiency is attainable through significant investment in hydrogen storage and chemical synthesis, importing e-fuels remains the more cost-effective strategy. Both scenarios, however, show a significant decrease in annual energy system costs, with 16.9-22.4 b€ in 2050 compared to 40.4 b€ in 2019. Additionally, the integration of agrivoltaics, hybrid photovoltaics-wind plants, and wave power can optimise land use. Achieving self-sufficiency requires larger initial investments but offers long-term economic and environmental advantages. This study offers a path for Belgium’s defossilisation, highlighting the significance of local renewable energy sources and international cooperation in trading e-fuels.