Conceptual model of the gas system as an integrated part of the future Danish energy system

Abstract

Denmark has set the ambitious goal of achieving an energy system, which is independent of fossil fuels by 2050. This implies that the Danish energy system will experience a remarkable transformation in the future, heading towards energy production based on renewable energy sources (RES). Facing the challenging future, a smart integration of gas in the Danish energy system may – in an effective and cost-efficient way – contribute to a sustainable transition. The FutureGas research project addresses these issues considering a smart integration of gas, which includes a development of: 1) flexible production of power and heat to support integration of fluctuating renewables, 2) decentralised production and collection of renewable gases, 3) transmission and storage at national and international levels, 4) distribution of gas to transport, power and heat as well as to the industrial sector. To investigate the transition of the Danish energy system, a system perspective is needed, which allows assessment of possible synergies across different sectors. Development of energy system models, which can facilitate integrated modelling of the entire energy system including the power, district heating, gas, and transport systems are therefore a central part of the project. In this paper, a conceptual model of the gas system as an integrated part of the future energy system is developed. The conceptual model is developed to ensure that all important aspects of modelling the gas system are represented in a sufficiently detailed way to properly analyze the potential future interaction between the gas sector and the remaining energy system. The modelling framework will comprise a detailed representation of the power, district heating and gas systems, while sectors such as the transport and industry will be partially represented through exogenously specified demands. Specifically, the conceptual model of the future gas system includes production, conditioning, transmission, storage, trade and use. The conceptual model highlights the important variables and parameters as well as necessary restrictions. The conceptual model will at a later stage be implemented in the existing energy system optimization model Balmorel, which currently has a detailed representation of the electricity and district heating sectors as well as in the spatiotemporal optimization model OptiFlow. The conceptual model will in the end, improve the current state of modelling integrated energy systems by combining the above-mentioned features with: 1) Investment optimization along with operation optimization. 2) High geographic resolution, which facilitates modelling the restrictions related to e.g. supply of district heating. 3) High temporal resolution. 4) Option to optimize with unit commitment. 5) Decommissioning of existing plants, making it possible to model the pathway towards future scenarios with high shares of RES.