Low-carbon optimal planning of an integrated energy station considering combined power-to-gas and gas-fired units equipped with carbon capture systems

•An integrated energy station optimal planning model is proposed.•Combined PtG and gas-fired unit equipped with CCS are considered in the planning model.•An improved EH formulation is proposed to describe the closed loops of energy flows and the energy output from the integrated energy station to external multi-energy networks.•The sensitive analysis are presented in case studies. To deal with the menace of global warming and energy crisis, low-carbon and sustainable energy consumption patterns are receiving more and more attention. Carbon capture and storage technologies, renewable energy sources and multi-energy systems are important measures to achieve low-carbon emission and sustainable energy development. In multi-energy systems, an integrated energy station is a key to realize the coupled and coordinated operation of multi-energy networks. This paper proposes an integrated energy station optimal planning model which considers the combined power-to-gas and gas-fired units equipped with carbon capture systems. To describe the closed loops of energy flows in the proposed integrated energy station, this paper presents an improved energy hub formulation based on the directed acyclic graph. Moreover, the output ports of the integrated energy station is connected to multi-energy networks to sell excess energy. The improved energy hub formulation is applied in the above-mentioned optimal planning model. The objective of the proposed optimal planning model is to minimize the total cost of integrated energy station, which consists of the investment cost, energy purchase cost, energy sales revenue and carbon cost. Finally, case studies are carried out to discuss and validate the effectiveness of the proposed optimal planning model and the improved energy hub formulation.