Remote ammonia production for the future energy demand of Belgium: Techno-economic optimization of local and remote ammonia production under uncertainty

Regions with abundantly available renewable energy are not necessarily the same as those with a high population density and high energy consumption. Therefore, renewable energy can be produced in optimal climate conditions with a remote renewable hub and transported to these population-dense regions. To establish this energy transport, ammonia provides a flexible, easy-to-handle energy carrier, which already showed a viable option for transporting energy from Australia to Japan. However, current literature rarely considers the impact of techno-economic uncertainty (variable energy consumption or uncertain capital and operational expenses) on the feasibility of this transport. Using those uncertainties, we performed a robust design optimization on the levelized cost of ammonia and the power-to-ammonia efficiency to compare the local (Belgium) and remote (Morocco) ammonia production and transport for Belgium. This paper provides the robust designs (i.e. least sensitive to uncertainty) for local and remote renewable ammonia production and the advantages of both approaches on the levelized cost and power-to-ammonia energy efficiency. The results confirm that ammonia production in regions with high solar irradiance followed by the transport of ammonia is cost-effective and robust (790 euro/tonneNH3 in mean and 128 euro/tonneNH3 in standard deviation) over local production (1334 euro/tonneNH3 in mean and 249 euro/tonneNH3 in standard deviation). However, local ammonia production provides for more efficient and less sensitive power-to-ammonia plant designs (53.6% in mean and 0.1% in standard deviation), while the remote production is less efficient and more sensitive to uncertainties (47.9% in mean and 1.53% in standard deviation). Both objectives are highly influenced by the capacity of the photovoltaic arrays and the electrolyzers, wherein in the case of Morroco, the backup capacity plays a significant role in the system’s efficiency. Future work aims to perform a techno-economic environmental evaluation of this robust design optimization, including environmental indicators like recycling of composite materials and depletion of rare materials

Robust integration of direct air capture in power-to-methane systems: techno-economic feasibility study under uncertainty

Direct Air Capture (DAC) technologies extract CO2 directly from the atmosphere and, therefore, compensate for the emissions from sectors that are difficult to decarbonize, e.g. aviation and heavy-duty mobility. However, due to the diluted CO2 in the atmosphere, DAC suffers from high costs and a significant energy footprint. When integrating DAC in power-to-gas systems, several underexplored synergies unfold that reduce the energy and water demand of the system, such as waste heat recycling from methanation and water recovery in the DAC unit. Interconnecting these energy and water streams results in a highly integrated system that is fragile towards changes in ambient and operating conditions. We developed a power-to-gas system with solid sorbent direct air capture and evaluated the energy efficiency and water self-sufficiency ratio under uncertain ambient and operating conditions. The results illustrate that operating at a desorption temperature of 61C, instead of 100oC, results in a water self-sufficient system under average ambient conditions for Belgium, at the expense of a reduction in the energy efficiency of 4% absolute (from 59% to 55%). Considering ambient and operating uncertainties results in a limited uncertainty on the energy efficiency (mean = 59.4%, standard deviation = 0.61%), but a significant uncertainty on the water self-sufficiency ratio (mean = 49.6%, standard deviation = 6.18%). Adopting time series for the ambient conditions is the main action to reduce uncertainty on the quantities of interest. Future work will focus on the dynamic operation of the system, including energy storage and renewable energy technologies

Importing renewable energy to EU via hydrogen vector: Levelized cost of energy assessment

European Green Deal sets the EU’s target towards becoming the world’s first climate-neutral continent by 2050. To achieve the 2050 Green Deal target, multi-combined actions are required, such as increasing renewable energy (RE) production in the EU, enhancing efficiency, and importing RE. The limited area, high population density, and geographical position constrain the EU’s RE self-sufficiency; in fact, the energy import dependency of the European Union (EU-27) reached 58.4% and 60.7% in 2018 and 2019, respectively. Interestingly, the final energy consumption by fuel comprises 23% of electricity and 77% of molecules. Consequently, a sustainable energy system requires not only green electricity but green molecules as well to move from fossil to electrified chemical industry (chemistree). In this context, the work analyses the LCOE of importing RE from Morocco, Algeria, Egypt, and Saudi Arabia to selected locations in the EU namely Rome, Madrid, and Cologne, since they have both a well-established energy importing/exporting network with the EU and a high potential of RE sources. A promising LCOE of H2 is found in all importing scenarios with an average of 5.20 €/kgH2. Hydrogen transport via pipelines (0.14 €/kg/1000 km) is found to be the optimal solution for the studied cases. Further investigation is required for importing RE via other types of molecules and e-fuels such as ammonia, methanol, and methane from the Middle East and North Africa (MENA) to the EU