Authors: Binqadhi H, AlMuhaini M, Poor H, Flynn D, Huang H
Name of Journal: IET Cyber-Physical Systems: Theory & Applications
Abstract: Cyber-physical power systems (CPPS) are integral to meeting society’s demand for secure, sustainable, affordable and resilient critical networks and services. Given the convergence of decarbonising, heating, cooling, and transportation networks onto cyber-physical power systems (CPPS), this takes on increased significance. This paper introduces an innovative approach to the open challenge of how we evaluate CPPS resilience, presenting the use of network motifs and Monte Carlo simulations. We demonstrate how our methodology enables a comprehensive analysis of CPPS by capturing the interdependence between cyber and physical networks and by accounting for inherent uncertainties in cyber and physical components. Specifically, this method incorporates the dynamic interplay between the physical and cyber networks, presenting a time-dependent motif-based resilience metric. This metric evaluates CPPS performance in maintaining critical loads during and after diverse extreme events in cyber and/or physical layers. The resilience status of the system is determined using the prevalence of 4-node motifs within the system’s network, offering valuable redundant paths for critical load supply. The study models a variety of natural events, including earthquakes, windstorms, and tornadoes, along with cyber-attacks while accounting for their inherent uncertainties using Monte Carlo simulation. The proposed approach is demonstrated through two test CPPS, specifically the IEEE 14-bus and IEEE 30-bus test systems, affirming its effectiveness in quantifying CPPS resilience. By comprehensively addressing system dynamics, interdependencies, and uncertainties, the proposed technique advances our understanding of CPPS and supports resilient system design.
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Authors: Couraud B, Norbu S, Andoni M, Robu V, Flynn D
Abstract: Local flexibility markets have emerged as a promising solution to solve distribution grid’s constraints at a lower cost than grid reinforcement. In this paper, we propose a local flexibility market framework based on optimal power flow (OPF) computation to allow a Community Distributed System Operator (C-DSO) to coordinate local flexibility provided by distributed generators and residential consumers. This local flexibility market allows the Distributed System Operator (DSO) to select the most cost-effective mix of flexible assets that addresses voltage excursions and grid congestions. It builds on an existing OPF formulation applicable only to energy markets, and extends it to the coordination of electrical flexibility. It considers active and reactive power while being suitable for imbalanced distribution grids analysis. Finally, it is implemented on the European low voltage test network with real consumption data and large solar PV penetration to solve local grid constraints. The formulation optimises the flexibility effort while the power flow accuracy presents an error below 2.9% as compared with OpenDSS.
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Authors: Fakhreddine, J., Dodds, P. E., Butnar, I
Name of Journal: International Journal of Hydrogen Energy
Abstract: Trade of hydrogen, as an energy commodity, would enable its widespread use in global energy systems. Hydrogen, unlike electricity, could be traded globally in its pure form or as a derivative compound (e.g. ammonia).
The development and potential size of global hydrogen trade remains uncertain due to technological, economic, infrastructural, and political complexities. We critically review how hydrogen trade models represent: (i) hydrogen supply and demand; (ii) derivatives supply and demand; (iii) hydrogen and derivative trade; and (iv) policy aspects affecting hydrogen scale-up.
While energy system models have the most detailed representation of hydrogen production and end-use demands, supply chain and techno-economic models have more detailed representations of trade supply chains of hydrogen and hydrogen derivatives. The implications of hydrogen policies have received limited consideration across all three model paradigms. Consequently, none of these approaches is yet to successfully and comprehensively represent the complexity of hydrogen and derivative trade systems.
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Authors: Zhang, R., Li, Z., Liu, P., Hawkes, A.D
Name of Journal: Sustainable Cities and Society
Abstract:Community energy systems globally are undergoing profound revolution towards sustainability, but face significant uncertainties from varying community conditions and differing preferences of decision-makers. While stochastic programming addresses parameter uncertainties effectively, growing attention has been directed towards “modelling to generate alternatives” (MGA), which provides diverse near-cost-optimal solutions to accommodate the varied needs of decision-makers beyond the limits of finite model structures. However, it is rarely recognized that these alternatives may differ significantly beyond economics, particularly in system resilience to renewable fluctuations, posing risks in achieving a sustainable and reliable community energy future through diversification. By introducing “modeling to generate resilience” (MGR), we propose a hierarchical algorithm and a quantile sampling to identify diverse and resilient alternatives, addressing both parameter uncertainty in renewables and structural uncertainty arising from model imperfections. With a campus community case, we find alternatives generated by tradition MGA may experience resilience degradation, while the modified algorithm ensures both diversity and resilience, reducing the average energy deficiency by 65%. Quantile sampling reveals four resilience characteristics within near-optimal space, navigating decision-makers in flexibly adjusting technology installations while ensuring system resilience. This offers practical insights for reliable energy infrastructure deployment under hybrid uncertainties incorporating diverse decision preferences and variable real-world conditions.
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Authors: Morteza Shafiekhani, Meysam Qadrdan
Name of Journal: Applied Energy
Abstract: The UK has set an objective of achieving a clean power by 2030, with a specific commitment to deploying 50 GW of offshore wind capacity within the same timeframe. However, the current transmission network lacks the capacity to accommodate these ambitious goals, highlighting the urgent need for substantial reinforcement to support the increased generation and demand at the transmission level. This paper investigates the integration of Battery Energy Storage Systems (BESS) as a non-networked solution, offering a timely and less expensive alternative to traditional network upgrades to address transmission bottlenecks in Great Britain (GB). Using DIgSILENT PowerFactory 2024, the study models the GB transmission network for 2024 and 2030, focusing on peak winter and minimum summer demand scenarios. Contingency analysis and hosting capacity assessments have identified critical bottlenecks which pose significant risks to system reliability during peak periods. This study focuses on South Wales, examining how flow decomposition techniques can be applied to identify locations for BESS deployment to address these bottlenecks. The findings demonstrate that strategically placed BESS can effectively alleviate transmission system bottlenecks. For the specific case analysed, the equivalent annualised cost of the non-networked solution is significantly lower, ranging from 38 % to 63 % of the cost of line reinforcement. Additionally, this approach offers the advantages of faster implementation and enhanced facilitation of renewable energy integration, underscoring its potential as an efficient solution for addressing transmission network bottlenecks.
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Authors: Cameron Aldren, Nilay Shah, Adam Hawkes
Name of journal: Cell Reports Sustainability
Given disparities in renewable energy potentials across different geographies, there is increasing motivation to export energy from areas of low-cost production to those where costs are high, thereby facilitating economical decarbonization at a global scale. While the hydrogen economy promises an ability to transport renewable energy, it is currently falling short of cost targets set by policymakers, due to technological costs and inefficiencies. To transport hydrogen, there are two leading choices: physical and chemical conversion of the low-density molecule. These choices have been found to expose the value chains to distinct sources of uncertainty between equipment cost (physical as liquid hydrogen) and energy efficiency (chemical as ammonia). Ammonia was found to be more cost effective if it can be used directly (rather than being converted back to hydrogen), but there is no clear optimal choice when the ammonia is converted back to hydrogen. This serves to promote ammonia, as our research finds it to always be either cheaper or equally as expensive as liquid hydrogen. While this research projects to a net-zero 2050 scenario, there is potential for cost reductions and efficiency improvements beyond that of what is predicted by this research. Given the maturity of ammonia production technology, there are limited strides to be made in improving the efficiency of its production process. However, hydrogen liquefaction is in its infancy, and given the unprecedented cost reductions seen in adjacent low-carbon technologies, such as wind turbines and electrolysers, the capital cost for liquefaction technology could follow a similar trend. Combined with the capital sensitivity of the liquid hydrogen value chain, there is potential to exploit this trend to see a massive reduction in cost. Large cost reductions are necessary for the hydrogen economy to see deployment, so liquid hydrogen could be better poised to realize these reductions in the future.
Highlights
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Authors: Akhil Joseph, Adib Allalham, Sara Louise Walker
Name of Journal: International Journal of Electrical Power & Energy Systems
Abstract: Meeting carbon reduction targets and enhancing energy supply flexibility necessitate the integration of natural gas and electricity networks, coupled with increased adoption of renewable energy. Bidirectional hydrogen-based Vector-Coupling Storage (VCS) offers a promising avenue for efficiently utilising surplus power from renewables, linking hydrogen as an energy carrier and storage with the Integrated Energy System (IES). This paper introduces a game-theoretic planning model for IES, encompassing natural gas, electricity, and independent VCS participants in a liberalised market. A game-theoretic model for capacity investment under an oligopolistic market structure in the liberalised energy market context is developed to capture the strategic behaviour of market participants. An annual investment model and an hourly operation simulation model are used to evaluate the value of hydrogen production, coupling components, and vector coupling storage in long-term investment decisions. The model, applied to the North of Tyne region in the UK, employs a scaled-down Future Energy Scenario dataset, reflecting a regional trajectory towards a net-zero emission target by 2050. Simulation results highlight market liberalisation’s crucial role in attracting investments in renewable energy and hydrogen systems. Conversion efficiencies of electrolysers and fuel cells emerge as key profitability determinants, emphasising the significance of achieving at least 50% round trip efficiency for profitable vector coupling storage. The findings quantify the advantages of large-scale VCS investments over Li-ion battery storage.
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Authors: Tong Zhang, Meysam Qadrdan, Jianzhong Wu, Benoit Couraud, Martin Stringer, Sara Walker, Adam Hawkes, Adib Allahham, David Flynn, Danny Pudjianto, Paul Dodds, Goran Strbac
Name of Journal: ICAE 2023
Abstract: The lack of clarity and uncertainty about hydrogen’s roles, demand, applications, and economics has hindered hydrogen development. This paper presents an integrated whole energy system (IWES) model to optimise the planning and operation of an energy system; the model is used to identify the role of hydrogen technologies in decarbonising energy systems, improving system flexibility and enhancing energy system security and resilience against extreme weather. The studies were conducted on the future (year 2050) Great Britain’s energy system to understand the hydrogen infrastructure capacity needed and their utilisation from the production, transport, storage, and demand under different scenarios. In the models, hydrogen technologies will compete against other alternative technologies, and the optimisation models will determine the least-cost solution. The studies demonstrate that hydrogen is essential for providing flexibility, energy system security and resilience against extreme weather. Synergy across hydrogen assets reduces the cost of hydrogen heating, which can be cost-competitive against the heat electrification approach.
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Authors: Strbac G, Pudjianto D, Ameli M
Name of Journal: ICAE 2023
Abstract: The lack of clarity and uncertainty about hydrogen’s roles, demand, applications, and economics has hindered hydrogen development. This paper presents an integrated whole energy system (IWES) model to optimise the planning and operation of an energy system; the model is used to identify the role of hydrogen technologies in decarbonising energy systems, improving system flexibility and enhancing energy system security and resilience against extreme weather. The studies were conducted on the future (year 2050) Great Britain’s energy system to understand the hydrogen infrastructure capacity needed and their utilisation from the production, transport, storage, and demand under different scenarios. In the models, hydrogen technologies will compete against other alternative technologies, and the optimisation models will determine the least-cost solution. The studies demonstrate that hydrogen is essential for providing flexibility, energy system security and resilience against extreme weather. Synergy across hydrogen assets reduces the cost of hydrogen heating, which can be cost-competitive against the heat electrification approach.
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Authors: Amiri M, Ameli M, Strbac G, Pudjianto D
Name of Journal: Energies
Abstract: The integration of gas and electricity networks has emerged as a promising approach to enhance the overall flexibility of energy systems. As the transition toward sustainable and decarbonized energy sources accelerates, the seamless coordination between electricity and gas infrastructure becomes increasingly crucial. This paper presents a comprehensive review of the state-of-the-art research and developments concerning the flexibility in the operation of low-carbon integrated gas and electricity networks (IGENs) as part of the whole system approach. Methods and solutions to provide and improve flexibility in the mentioned systems are studied and categorized. Flexibility is the system’s ability to deal with changes and uncertainties in the network while maintaining an acceptable level of reliability. The presented review underscores the significance of this convergence in facilitating demand-side management, renewable energy integration, and overall system resilience. By highlighting the technical, economic, and regulatory aspects of such integration, this paper aims to guide researchers, policymakers, and industry stakeholders toward effective decision-making and the formulation of comprehensive strategies that align with the decarbonization of energy systems.
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