Integration of non-energy among the end-use demands of bottom-up whole-energy system models

Abstract

The complexity of bottom-up energy system models has progressively grown to enhance the representativeness of the system under analysis. Among them, whole-energy system models aim at representing the energy resources, conversion technologies, and energy demands of regions (i.e., a country) in its entirety. Despite this effort leading to an increased number of conversion processes modeled, the typologies of the end-use demand have remained limited to three categories: electricity, heat, and transportation. A fourth category, herein addressed as the non-energy demand, has widely been neglected. Being associated with the production of chemicals (i.e., plastics and fertilizers), the non-energy demand represents 10% of the world’s total end-use demand. Its relevance becomes fundamental in analyses that define the optimal defossilization pathways of energy systems with high dependence on fossil resources. This contribution introduces a schematic representation of the conversion processes involved in the satisfaction of the non-energy demand. Through its implementation in a bottom-up whole-energy system model, it evaluates the impact of this additional end-use in the configuration of the optimal energy system. In this study, the Belgian energy system, characterized by a penetration of the chemical and the petrochemical industries up to 20% of its total end-use demand, is taken as a reference case. The transition to a defossilized energy system is enforced through a snapshot analysis with a progressively more restrictive emissions cap. The results emphasize the role of renewable carriers (i.e., methanol and ammonia) in the defossilization of the energy system, otherwise hindered when the non-energy demand is neglected. The 100% import of these carriers at the lowest emissions cap highlights the potential dependence of the country under analysis, with limited availability of renewable resources, from countries exporting renewable methanol and ammonia.

Validation of a Method to Select a Priori the Number of Typical Days for Energy System Optimisation Models

“…This model is built as an extension of the open-source model EnergyScope TD [41]. The validity of both the original model [5,[54][55][56][57][58][59][60][61] and the extension [51,62,63] was verified in previous studies.…”

Global land and water limits to electrolytic hydrogen production using wind and solar resources

“…However, hydrogen is involved in the production of HVCs only as feedstock for the production of methanol, consumed in the production of HVCs (12% of methanol used for HVCs in 2017 47 ). Accordingly, the definition of chemical industry with respect to the use of hydrogen only refers to the production of ammonia and methanol 47,48 , which includes the use of hydrogen for HVCs production as final product. Hydrogen use in the chemical industry is expected to grow, together with the increase in ammonia and methanol demands 47,49 .…”

“…Both ammonia and methanol can potentially be used as fuels or to distribute and store hydrogen within an ammonia-or methanol-economy 52,53,54 . Similar to previous studies 48 , we compute hydrogen demand from the main feedstocks used in the conversion process, i.e., natural gas and coal. The country-specific consumption of natural gas and coal for non-energy use is available from the historical World Energy Balances published by the International Energy Agency (IEA) 46 .…”

“…Current ammonia and methanol production have similar production routes, which rely on natural gas, respectively the Haber-Bosch process and the methanol synthesis. Alternative low-carbon routes exist and involve the production of hydrogen, which is an intermediate product, either from water electrolysis or biomass gasification 47,48,51 . Both ammonia and methanol can potentially be used as fuels or to distribute and store hydrogen within an ammonia-or methanol-economy 52,53,54 .…”

Navigating Bioenergy Horizons: A Critical Examination of Europe's Potential, with Belgium as a Case Study

“…A careful consideration of the underlying methodologies and assumptions is therefore required to compare the available results and draw conclusions on reasonable estimates. Most of the time in the literature, the potential estimates are taken as simple exogenous data for energy system modelling [7,8], with no further discussion on the systemic implications.…”