Imperial College London


Faculty of EngineeringDepartment of Electrical and Electronic Engineering

Research Fellow







Electrical EngineeringSouth Kensington Campus





Publication Type

17 results found

Zhang X, Ameli H, Dong Z, Vecchi A, Gallego-Schmid A, Strbac G, Sciacovelli Aet al., 2022, Values of latent heat and thermochemical energy storage technologies in low-carbon energy systems: whole system approach, Journal of Energy Storage, Vol: 50, ISSN: 2352-152X

Thermal energy storage (TES) is widely expected to play an important role in facilitating the decarbonization of the future energy system. Although significant work has been done in assessing the values of traditional sensible TES, less is known about the role, impact and value of emerging advanced TES at the system level. This is particularly the case of latent heat thermal energy storage (LHTES) and thermochemical energy storage (TCS). In this context, this paper is dedicated to evaluating the techno-economic values for the whole UK energy system of LHTES and TCS technology using an integrated whole energy system model. First, the key concepts of the whole system modelling framework are introduced. Unique to this work is that the economic benefits delivered by LHTES and TCS to different levels of theUK energy system infrastructure and various energy sectors through the deployment of TES are explicitly analyzed, which comprehensively demonstrates the values of selected TES technologies from the whole system perspective. A series of sensitivity studies are implemented to analyze the advantages and disadvantages of LHTES and TCS underdifferent conditions. The simulation results indicate that TES can benefit different sectors of the whole energy system and drive significant cost savings, but the whole system values of TES is closely dependent on the decarbonization requirement. Although LHTES is characterized by relatively low capital costs, when TES penetration is limited and carbon target is tight, the advantage of TCS is outstanding due to its high energy density.

Journal article

Davari MM, Ameli H, Ameli MT, Strbac Get al., 2022, Impact of local emergency demand response programs on the operation of electricity and gas systems, Energies, Vol: 15, ISSN: 1996-1073

With increasing attention to climate change, the penetration level of renewable energy sources (RES) in the electricity network is increasing. Due to the intermittency of RES, gas-fired power plants could play a significant role in backing up the RES in order to maintain the supply–demand balance. As a result, the interaction between gas and power networks are significantly increasing. On the other hand, due to the increase in peak demand (e.g., electrification of heat), network operators are willing to execute demand response programs (DRPs) to improve congestion management and reduce costs. In this context, modeling and optimal implementation of DRPs in proportion to the demand is one of the main issues for gas and power network operators. In this paper, an emergency demand response program (EDRP) is implemented locally to reduce the congestion of transmission lines and gas pipelines more efficiently. Additionally, the effects of optimal implementation of local emergency demand response program (LEDRP) in gas and power networks using linear and non-linear economic models (power, exponential and logarithmic) for EDRP in terms of cost and line congestion and risk of unserved demand are investigated. The most reliable demand response model is the approach that has the least difference between the estimated demand and the actual demand. Furthermore, the role of the LEDRP in the case of hydrogen injection instead of natural gas in the gas infrastructure is investigated. The optimal incentives for each bus or node are determined based on the power transfer distribution factor, gas transfer distribution factor, available electricity or gas transmission capability, and combination of unit commitment with the LEDRP in the integrated operation of these networks. According to the results, implementing the LEDRP in gas and power networks reduces the total operation cost up to 11% and could facilitate hydrogen injection to the network. The proposed hybrid model is implem

Journal article

Amiri MM, Ameli H, Ameli MT, Strbac Get al., 2022, Investigating the effective methods in improving the resilience of electricity and gas systems, Whole Energy Systems: Bridging the Gap via Vector-Coupling Technologies, Publisher: Springer, Cham, ISBN: 978-3-030-87652-4

Consumption of natural gas and the share of renewable energy in meeting global energy demand have grown significantly. Consequently, gas and electrical grids are becoming more integrated with fast responding gas-fired power stations, providing the primary backup source for renewable electricity in maintaining supply-demand balance. For an engineering system (e.g., gas and electricity systems infrastructure), many definitions of similar essence have been proposed, focusing on the ability to deal with disruptions. Taking the importance of actions prior, during, and afterward of an adverse event in mind, resilience is defined as a system’s ability to anticipate, resist, absorb, respond to, adapt to, and recover from a disturbance. Hence, in this chapter the importance of resiliency in the electricity and gas network’s cooperation is demonstrated, and different strategies and methods to increase resiliency are investigated.

Book chapter

Chocontá Bernal D, Muñoz E, Manente G, Sciacovelli A, Ameli H, Gallego-Schmid Aet al., 2021, Environmental assessment of latent heat thermal energy storage technology system with phase change material for domestic heating applications, Sustainability, Vol: 13, Pages: 1-17, ISSN: 2071-1050

The emissions generated by the space and water heating of UK homes need to be reduced to meet the goal of becoming carbon neutral by 2050. The combination of solar (S) collectors with latent heat thermal energy storage (LHTES) technologies with phase change materials (PCM) can potentially help to achieve this goal. However, there is limited understanding of the environmental sustainability of LHTES technologies from a full life cycle perspective. This study assesses for the first time 18 environmental impacts of a full S-LHTES-PCM system from a cradle to grave perspective and compares the results with the most common sources of heat in UK homes. The results show that the system’s main environmental hotspots are the solar collector, the PCM, the PCM tank, and the heat exchanger. The main cause of most of the impacts is the extensive consumption of electricity and heat during the production of raw materials for these components. The comparison with other sources of household heat (biomass, heat pump, and natural gas) indicates that the S-LHTES-PCM system generates the highest environmental impact in 11 of 18 categories. However, a sensitivity analysis based on the lifetime of the S-LHTES-PCM systems shows that, when the lifetime increases to 40 years, almost all the impacts are significantly reduced. In fact, a 40-year S-LHTES-PCM system has a lower global warming potential than natural gas.

Journal article

Mohammadi-Ivatloo B, Shotorbani AM, Anvari-Moghaddam A, 2021, Energy Storage in Energy Markets Uncertainties, Modelling, Analysis and Optimization, Publisher: Academic Press, ISBN: 9780128203835

The book provides deep insights on potential benefits and revenues, economic evaluation, investment challenges, risk analysis, technical requirements, and the impacts of energy storage integration.


Shabazbegian V, Ameli H, Ameli MT, Strbac G, Qadrdan Met al., 2021, Co-optimization of resilient gas and electricity networks; a novel possibilistic chance-constrained programming approach, Applied Energy, Vol: 284, ISSN: 0306-2619

Gas-fired power plants are commonly employed to deal with the intermittency of renewable energy resources due to their flexible characteristics. Therefore, the intermittency in the power system transmits to the gas system through the gas-fired power plants, which makes the operation of these systems even more interdependent. This study proposes a novel possibilistic model for the integrated operation of gas and power systems in the presence of electric vehicles and demand response. The model takes into account uncertainty in demand prediction and output power of wind farms, which is based on possibility and necessity theories in fuzzy logic through modeling uncertain parameters by Gaussian membership function. Moreover, a contingency analysis algorithm based on maximin optimization is developed to enhance the resiliency in the integrated operation of these systems by finding the worst-case scenario for the outage of components. The proposed model is implemented on a Belgium gas network and IEEE 24-bus electricity network. It is demonstrated that the possibilistic model allows the gas network to respond to the demand variations by providing a sufficient level of linepack within the pipelines. As a result, gas-fired power plants are supposed to commit more efficiently to cope with the intermittency of wind farms, which reduce the wind curtailment by 26%. Furthermore, it is quantified that through applying the contingency analysis algorithm in presence of demand response and electrical vehicles, the costs of operation and load shedding is reduced up to 17% and 83%, respectively.

Journal article

Shahbazbegian V, Ameli H, Ameli M, Strbac Get al., 2020, Stochastic optimization model for coordinated operation of natural gas and electricity networks, Computers and Chemical Engineering, Vol: 142, Pages: 1-18, ISSN: 0098-1354

Renewable energy sources will anticipate significantly in the future energy system paradigm due to their low cost of operation and low pollution. Considering the renewable generation (e.g., wind) intermittency, flexible gas-fired power plants will continue to play their essential role as the main linkage of natural gas and electricity networks, and hence coordinated operation of these networks is beneficial. Furthermore, uncertainty is always found in gas demand prediction, electricity demand prediction, and output power of wind generation. Therefore, in this paper, a two-stage stochastic model for operation of natural gas and electricity networks is implemented. In order to model uncertainty in these networks, Monte Carlo simulation is applied to generate scenarios representing the uncertain parameters. Afterwards, a scenario reduction algorithm based on distances between the scenarios is applied. Stochastic and deterministic models for natural gas and electricity networks are optimized and compared considering integrated and iterative operation strategies. Furthermore, the value of flexibility options (i.e., electricity storage systems) in dealing with uncertainty is quantified. A case study is presented based on a high pressure 15-node gas system and the IEEE 24-bus reliability test system to validate the applicability of the proposed approach. The results demonstrate that applying the stochastic model of gas and electricity networks as well as considering integrated operation strategy in the presence of flexibility provides different benefits (e.g., 14% cost savings) and enhances the system reliability in the case of contingency.

Journal article

Rostami AM, Ameli H, Ameli MT, Strbac Get al., 2020, Secure operation of integrated natural gas and electricity transmission networks, Energies, Vol: 13, ISSN: 1996-1073

The interaction between natural gas and electricity networks is becoming more significant due to the projected large penetration of renewables into the energy system to meet the emission targets. This is due to the role of gas-fired plants in providing backup to renewables as the linkage between these networks. Therefore, this paper proposes a deterministic coordinated model for the secure and optimal operation of integrated natural gas and electricity transmission networks by taking into account the N-1 contingency analysis on both networks. In order to reduce the computational burden and time, an iterative algorithm is proposed to select the critical cases and neglect other contingencies, which do not have a significant impact on the energy system. The proposed integrated mixed-integer nonlinear programming operational model is evaluated and compared to another enhanced separated model on the IEEE 24-bus and 15-node gas test systems. The results emphasize the importance and effectiveness of the proposed framework (up to 6.7% operational costs savings are achieved).

Journal article

Rostami AM, Ameli H, Ameli MT, Strbac Get al., 2020, Information-Gap Decision Theory for Robust Operation of Integrated Electricity and Natural Gas Transmission Networks, 2020 International Conference on Smart Energy Systems and Technologies (SEST)

Natural gas consumption and the share ofrenewable energy in meeting global energy demand has growndramatically in the recent years. On the other hand, the rapidgrowth of gas-fired generating units (GFU) (i.e., producing lowercarbon dioxide emissions compared to coal-fired generating units),could play a key role in more integration of renewable energysources (RESs) into the system due to their high flexibility.Therefore, the interaction between the electricity and natural gasnetworks (ENGN) becomes more challenging. This paper proposesa robust multi objective integrated mixed integer nonlinearoptimization model, utilizing information-gap decision theory(IGDT), for secure and optimal operation of ENGN consideringsecurity constraints as well as gas and electricity load demanduncertainties. This bi-objective optimization problem is modifiedusing normalization in the weighted sum method in order toensuring the consistency of the optimal solutions. The proposedframework is validated on the modified IEEE 24-bus powersystem with a 15-node natural gas system.

Conference paper

Ameli H, qadrdan M, Strbac G, 2020, Coordinated operation of gas and electricity systems for flexibility study, Frontiers in Energy Research, Vol: 8, ISSN: 2296-598X

The increase interdependencies between electricity and gas systems, driven by gas-fired power plants and gas electricity-driven compressors, necessitates detailed investigation of such interdependencies, especially in the context of increased share of renewable energy sources.6 In this paper, the value of an integrated approach for operating gas and electricity systems is assessed. An outer approximation with equality relaxation (OA/ER) method is used to deal with the optimization class of mixed integer non-linear problem of integrated operation of gas and electricity systems. This method significantly improved the efficiency of the solution algorithm and achieved nearly 40% reduction in computation time compared to successive linear programming. The value of flexibility technologies including flexible gas compressors, demand side response, battery storage, and power-to-gas is quantified in the operation of integrated gas and electricity systems in GB 2030 energy scenarios for different renewable generation penetration levels. The modeling demonstrates that the flexibility options will enable significant cost savings in the annual operational costs of gas and electricity systems (up to 21%). On the other hand, the analysis carried out indicates that deployment of flexibility technologies support appropriately the interaction between gas and electricity systems.

Journal article

Ameli H, Qadrdan M, Strbac G, Ameli MTet al., 2020, Investing in flexibility in an integrated planning of natural gas and power systems, IET Energy Systems Integration, Vol: 2, Pages: 101-111, ISSN: 2516-8401

The growing interdependencies between natural gas and power systems, driven by gas-fired generators and gas compressors supplied by electricity, necessitates detailed investigation of the interactions between these vectors, particularly in the context of growing penetration of renewable energy sources. In this research, an expansion planning model for integrated natural gas and power systems is proposed. The model investigates optimal investment in flexibility options such as battery storage, demand side response, and gas-fired generators. The value of these flexibility options is quantified for gas and electricity systems in GB in 2030. The results indicate that the flexibility options could play an important role in meeting the emission targets in the future. However, the investment costs of these options highly impact the future generation mix as well as the type of reinforcements in the natural gas system infrastructure. Through deployment of the flexibility options up to £24.2b annual cost savings in planning and operation of natural gas and power systems could be achieved, compared to the case that no flexibility option is considered.

Journal article

Ameli H, Qadrdan M, Strbac G, 2019, Coordinated operation strategies for natural gas and power systems in presence of gas-related flexibilities, IET Energy Systems Integration, Vol: 1, Pages: 3-13, ISSN: 2516-8401

A detailed investigation of interaction between natural gas and power systems is necessary, due to the increasinginterdependency of these vectors, especially in the context of renewable generations integration growth into the grid. In this paper,an outer approximation with equality relaxation decomposition method is proposed to solve a mixed-integer non-linear problemrepresenting the operation of coupled natural gas and power systems. The proposed coupled modeling of natural gas and powersystems is compared to a decoupled operational modeling. It is demonstrated that operating gas and electricity as a coupledsystem resulted in about 7% operational cost savings. In addition, the value of gas-related flexibility options, including flexiblegas compressors, flexible gas generation plants, and gas interconnections, to the operation of natural gas and power systems isquantified for a 2030 GB energy system. It is shown that if the natural gas and power systems are flexible enough, operation of thesystems in the decoupled approach is almost the same as the coupled model and therefore there is no need to reform the currentenergy market framework to make the systems fully coupled.

Journal article

Ameli H, Qadrdan M, Strbac G, 2017, Techno-economic assessment of battery storage and Power-to-Gas: A whole-system approach, 9th International Conference on Applied Energy (ICAE), Publisher: Elsevier, Pages: 841-848, ISSN: 1876-6102

The power systems in many countries are undergoing a radical transformation through employing a large capacity of renewable generation technologies such as wind turbine and solar photovoltaic. The power generation by wind and solar resources are variable and difficult to predict. Therefore, growing capacities of such technologies is expected to introduce challenges regarding balancing electricity supply and demand. This paper investigates the role of battery storage and power-to-gas systems to accommodate large capacity of intermittent power generation from wind and solar and therefore facilitates matching electricity supply and demand. The Combined Gas and Electricity Networks (CGEN) model was used to optimize the operation of gas and electricity networks in GB for typical weeks in winter and summer in 2030. The role of different capacity of battery storage and power-to-gas systems in reducing the wind curtailment and operating cost of the system were quantified and compared with the annualized cost of these technologies.

Conference paper

Ameli H, Abbasi E, Ameli MT, Strbac Get al., 2017, A fuzzy-logic-based control methodology for secure operation of a microgrid in interconnected and isolated modes, International Transactions on Electrical Energy Systems, Vol: 27, ISSN: 2050-7038

Due to the global concerns regarding the climate change, integration of renewable energy sources is considered as a mitigation approach in electric power generation. This requires advanced frequency and voltage control methodologies to overcome the challenges especially in microgrids. This paper presents a 2-step frequency and voltage control methodology for microgrids with high penetration of variable renewable energy sources. An optimized Proportional-Integral controller is designed for a Superconductor Magnetic Energy Storage System to minimize the transient frequency deviations. In cases that the Superconductor Magnetic Energy Storage System cannot stabilize the microgrid frequency in the isolated mode, the microgrid controller activates the next level of the frequency control. In the second level, an intelligent fuzzy-logic frequency controller is designed to adjust controllable loads, controllable generation units as well as perform load shedding. In the interconnected mode, the microgrid controller is able to activate the second level to contribute to the system frequency control. Finally, an intelligent fuzzy-logic voltage controller, realized through distribution static synchronous compensator, is devised to control the voltage magnitude of the main feeders of the microgrid. In this work, a real-time operation algorithm for frequency as well as voltage control is proposed and has been tested by set of simulations on a low voltage benchmark network.

Journal article

Ameli H, Strbac, Qadrdan, 2017, Value of gas network infrastructure flexibility in supporting cost effective operation of power systems, Applied Energy, Vol: 202, Pages: 571-580, ISSN: 1872-9118

The electricity system balancing is becoming increasingly challenging due to the integration of Renewable Energy Sources (RES). At the same time, the dependency of electricity network on gas supply system is expected to increase, as a result of employing flexible gas generators to support the electricity system balancing. Therefore the capability of the gas supply system to deliver gas to generators under a range of supply and demand scenarios is of a great importance. As potential solutions to improve security of gas and electricity supply, this paper investigates benefits of employing flexible multi-directional compressor stations as well as adopting a fully integrated approach to operate gas and electricity networks. A set of case studies for a GB gas and electricity networks in 2030 have been defined to quantify the value of an integrated operation paradigm versus sequential operation of gas and electricity networks. The results indicate there are significant overall system benefits (up to 65% in extreme cases) to be gained from integrated optimization of gas and electricity systems, emphasizing the important role of gas network infrastructure flexibility in efficiently accommodating the expected expansion of intermittent RES in future power systems.

Journal article

Qadrdan M, Ameli H, Strbac G, Jenkins Net al., 2017, Efficacy of options to address balancing challenges: integrated gas and electricity perspectives, Applied Energy, Vol: 190, Pages: 181-190, ISSN: 1872-9118

Integration of a large capacity of wind generation in the Great Britain(GB)electricity network is expected to pose a number of operational challenges. The variable nature of wind generation necessitates introduction of technologies that can provide flexibility to generation portfolios and therefore compensate for intermittency of wind generation. In this paper, the efficacy of three options to address electricity balancing challenges was evaluated: flexible gas-fired plants, electricity storage andPower-to-Gas system. The combined gas and electricity network model (CGEN) was enhanced and through adopting a rolling optimisation approach the model aims at minimising the operational cost of an integrated gas and electricity networks that represents a GBsystem in 2030. The potential impacts of employing each of the flexibility options on the operation of the integrated electricity and gas networks were investigated. The analysis showed that amongst all the flexibility options, the deployment of grid-scale electricity storage will achieve the highest reduction in the operational cost of the integrated system (£12 million reduction in a typical winter week, and £3 million reduction in a typical summerweek). The results of this study provide insights on the system-wide benefits offered by each of the flexibility options and role of the gas network in the energy system with large capacity of wind generation.

Journal article

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