Guest Editorial: Planning and operation of integrated energy systems for decarbonisation

Integrated energy systems’ decarbonization is vital to deal with the global warming problem. An integrated energy system, which is interconnected with various energy resources and highly aggregated with groups of residential, commercial, and/or industrial buildings, is becoming the primary target for low-carbon transition due to its large energy consumption and high carbon emission density. The decarbonisation of integrated energy systems is of great significance in achieving the goal of carbon neutrality. The integrated energy system generally provides ideas for integrating multiple elements of the urban energy system, such as electricity, natural gas, heat networks, as well as residential, commercial, industrial or associated service systems and transportation, which makes the mechanism and method of decarbonisation more difficult and complicated. Meanwhile, digital technologies such as IoT, ICT, machine learning, and big data are drawing much attention as they can aid the decarbonisation process. With these novel technologies' promotion, the improvement will be made in terms of economy, energy efficiency and environmental benefit when developing an integrated energy system towards low-carbon/zero-carbon.

This IET Smart Grid special issue on Planning and Operation of Integrated Energy Systems for Decarbonisation invites a broad spectrum of contributors from universities, industry, research laboratories, and policymakers to develop and present novel solutions and technologies that will facilitate and advance the agenda of deep decarbonisation of integrated energy systems.

This special issue solicits original research papers that target at, but are not restricted to, the following aspects. It is worth noting that this special issue places an emphasis on addressing the mutual research interests of academics and industry.

In this special issue, we have received several papers, all of which underwent the peer-review process. Of the submitted papers, only six have been accepted. Thus, the overall submissions were of high quality, which marks the success of this special issue.

The six accepted papers can be clustered into four main categories, including energy market, energy development, energy operation in distribution networks and state estimation. Among these categories, the first one offers a framework of energy market, such as peer-to-peer (P2P) transaction for third-party prosumers, operation and planning techniques for multi-stakeholders planning in distribution networks, whose authors are Xiang et al. The second one exhibits novelties in the energy management, such as power generation with flexible energy resource pathways evolution from the view of CO₂ emission, and renewable energies development in extreme scenario generation, whose authors are Li et al. and Peng et al. The third one proposes some methods for energy operation in distribution networks, such as the total supply capability (TSC) and operation modes analysis of low-voltage flexible distribution network (LVFDN), energy balancing and load curtailment strategy for hybrid AC/DC distribution network, whose authors are Zu et al. and Sarwar et al. The last one brings a systematic survey on dynamic state estimation for cybersecurity in cyber-physical power systems (CPPSs), whose authors are Zhou et al. A brief presentation of each of the paper in this special issue is as follows.

Xiang et al. propose a tri-layer distribution network expansion planning (DNEP) framework integrated with virtual P2P transactions to accommodate uncertainties and postpone investment in distribution networks. In addition, the common planning with distributed energy resources (DERs), multi-stakeholder operation and planning under the transactive energy market, P2P transactions are introduced and reviewed.

Zhou et al. reviewed the role of cybersecurity in cyber-physical power systems (CPPSs), focusing on the applications of dynamic state estimation (DSE) techniques. The three cyber resilience phases including prevention, detection, and mitigation of DSE techniques and applications to efficiently protect CPPS against cyberattacks are classified. Moreover, the benefits and limitations of each DSE technique are discussed and further suggestions for enhancing the cyber resilience of CPPS are given.

Li et al. introduce a CO₂ emission model of a regional power system based on a collaborative method. An estimable method of policy coordination is used to consider macro factors based on system dynamics and optimal allocation of high renewable permeable power systems with a flexible resource combination is established to consider micro factors based on random production simulation. Two strategies are proposed to deduce the energy structure with high-penetration renewable energy and flexible resources according to the drive of the CO₂ emission target.

Peng et al. propose a three-staged extreme scenario generation method for renewable energies to effectively and efficiently generate extremely high-power output scenarios. The simulation on a real-world dataset shows that the proposed method has superior performance in terms of extreme scenario generation, and the generated samples can successfully capture the temporal and spatial correlation of real scenarios of renewable energies.

Zu et al. consider typical structures and operation modes of LVFDN and TSC that formulate flexible power flow control and multi-level (medium- and low-voltage flexible interconnection) load transfer and then propose a TSC model of LVFDN, and a new algorithm based on the ‘branch and bound algorithm’ is also provided to fit the non-linear non-convex characteristics of the TSC model. The variations of TSC with different capacities of the low-voltage FID are analysed and theoretical basis for the application of flexible interconnection technology is provided.

Sarwar et al. propose an enhanced energy balancing and optimal load curtailment strategy for DC microgrid integration in hybrid AC/DC distribution networks, which aims at optimising resource utilisation, prioritising essential loads, and executing an optimal load curtailment strategy, thereby augmenting the stability of systems. The simulation results show the load curtailment approach can effectively maintain system stability and prevent blackouts during unforeseen events.

All of the six papers selected for this special issue show that various forms of targeted planning, flexible operation, suitably designed energy markets and state estimation with cybersecurity have paved the way for the integrated energy system decarbonisation. Yet, continued research efforts are deemed necessary to foster proper harvesting of the full value stream of these emerging technologies and achieving real net zero.