Low-carbon oriented optimal energy dispatch in coupled natural gas and electricity systems

The integrated energy system (IES) can leverage the synergy of different types of energy systems, which contain considerable potential in the overall carbon emission mitigation. To achieve the low-carbon transition, financial incentives such as carbon trading are employed in the electricity and natural gas sectors to encourage flexibly emission mitigation to cover the extra carbon costs. However, the existing trading policy applies unilateral mechanism, carbon costs are usually levied on power generation and gas supply companies. Utility companies would simply pass-through the carbon costs to consumers by incorporating them into upward energy prices. Further, due to more than one form of energy consumption in integrated components, there are twofold charges of carbon costs for some consumers in IES. It would be difficult to mitigate carbon emission effectively and efficiently without an equitable trading mechanism. It should be noted that end-use consumers are the underlying drivers of emissions in the energy supply chain. Therefore, this paper proposes a two-stage low-carbon operation planning model based on a bilateral trading mechanism with active demand side management (DSM), aiming to mitigate carbon emissions. The carbon emission flow (CEF) model is applied to track the emissions and calculate the carbon intensities, energy storage systems like battery and power-to-gas (P2G) are considered. The proposed model is tested on a modified IEEE 24-bus electricity system and a modified 20-bus natural gas system. According to the simulation results, the proposed model is effective to reduce carbon intensity by increasing the proportion of energy with low carbon intensity in the energy mix and further achieve carbon emission mitigation. Meanwhile, the demand side can also obtain extra environmental financial benefits by DSM and planned zero-emission facilities under the bilateral trading mechanism.