Whole Energy Systems

In recent years, the vector coupling of energy systems is in progress by integrating different energy vectors such as power, heat, and gas and also integration of different sectors such as residential, transportation, commercial, and industry parts for efficient utilization of energy sources such as natural gas, coal, diesel, and renewable energy sources. The energy crisis, air pollution issues, increasing trend of energy consumption, reliability issues, and especially increasing the share of variable renewable energy sources are the major drivers of this transition. Interaction among energy systems is achieved through a real or physical node or even a virtual node so-called the energy hub or multi-energy node. Enabling technologies for integrating energy systems are energy conversion systems (such as cogeneration and trigeneration systems, heat pumps, diesel generator, and boilers), energy storage systems (such as battery, thermal, cold, and hydrogen storage), information and communication technologies, and particularly decarbonizing components. Demand-side management is also essential for energy integration since it contributes to energy conservation and flexibility of energy demands. In this chapter, the concept and definition of vector-coupling concept in the whole energy systems is discussed. In addition, enabling technologies and challenges associated with integrating energy vectors are discussed.

The development of renewable energy infrastructure and technologies is accelerating. One of the main concerns in renewable electricity production is the emergence of generation intermittency and fluctuation along with existing load variability. Power-to-X could play a critical role in providing many technological methods to handle power supplies with the consistency and reliability of future energy systems. A comprehensive investigation of the various power-to-X technologies is provided in this chapter, which could be utilized to integrate the benefits of renewable energies whereas avoiding the limitations when used alone. As well, the latest advances in PtX technologies are investigated and discussed in detail since limitations must be overcome to implement infrastructures around the world.

This chapter presents a methodological framework for whole energy systems evaluation with underpinning principles, demonstrated through a case study. The framework provides a socio-technical approach for evaluation by combining stakeholders’ requirements with the system components and functions through a system-of-systems architecture methodology. The framework application involves three stages: scenario formulation, conceptual modelling and quantitative modelling, in an iterative process of feedback between the stages. The proposed framework is applied on a case study to evaluate the effectiveness of energy systems integration as a pathway for achieving the energy transition objectives. The case study is based on the local energy system of the North of Tyne region, UK. The case study demonstrates the framework application and presents evidence on the potential of energy systems integration in the region via vector-coupling technologies, including combined heat and power, power-to-gas and heat pumps, under different scenarios.

In this chapter, a method for energy integration of heating, cooling, and power generation and desalination systems in process industries will be studied using the Total Site integration approach. This approach can identify and measure energy production and consumption potentials of integrated process units with a holistic attitude. Integrating various units with different needs makes it possible to optimize energy generation and consumption in process industries by maximizing energy efficiency and minimizing energy consumption and related costs of the whole Total Site. This approach ensures that the Total Site system’s overall efficiency is optimal by providing a systematic method. The old methods, which were based on increasing each unit’s efficiency and cogeneration in each state, caused each unit to impact the other. As a result of this interaction, the system’s overall efficiency was reduced, or the optimal point exists only from each unit’s point of view. However, in a broader view, the systems were not optimal while working together.

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.

Restructuring in the electricity industry and the increasing use of electrical and thermal energy in the world has led to the more efficient use of combined heat and power (CHP) systems. On the other hand, investing in CHP systems will be beneficial for its owners; however, it is necessary to consider various limitations such as environmental pollutants in planning. In this study, environmental pollutants’ cost effect on the profit and optimal location of various CHP technologies, including microturbine, internal combustion engine, and the fuel cell, is investigated. Features are presented in this chapter, providing a comprehensive model for optimal placement of CHP, considering nonrenewable sources, electrical and thermal energy networks, annual planning for a 5-year horizon, and the cost of environmental pollutants. The proposed model is implemented in the GAMS software environment. The results show that the profit of resource owners depends on the type of technology used. It has also been found that the optimal installation location of the technologies used is affected by environmental pollutants.

In the recent decade, due to the increasing dependency of communities on energy, the issues related to optimal operation and energy management have been increasingly considered by researchers and beneficiaries in this field. In this regard, the subject of energy can be regarded as the critical challenge of humankind in the present century, including economic, environmental, and security contexts. The proposed solution to address these challenges is to move toward smart energy systems and utilizing renewable energy resources and energy storage systems, which have been introduced and discussed in various aspects in recent years. The power-to-X (P2X) facilities are a new framework for energy conversion technologies to improve energy systems’ optimal operation. Interconnected hybrid energy systems (IHESs) along with P2X facilities containing power-to-heat (P2H), power-to-cool (P2C), and power-to-hydrogen (P2Hy) technologies can supply disparate demands of energy systems locally. Also, IHESs can trade energy with each other, in addition to meeting individual demands. This approach improves systems’ efficiency, flexibility, and performance and reduces greenhouse gas emissions. In this chapter, the optimal coalition operation of IHESs using renewable and nonrenewable energy resources to mitigate operation and emission costs has been investigated. For more comparison, two case studies are considered. In the first case study, the individual optimal operation of each hybrid energy system (HES) is taken into account. In the second one, the optimal coalition operation of IHESs is modeled. The mixed-integer linear programming (MILP) optimization problem is solved in GAMS software under the CPLEX solver. The obtained results indicate that the interconnected operation of the HESs improves system performance and reduces system operating costs.

Nowadays, with vast value of expansion in both electric and heat demands, combined heat and power (CHP) system is a preferred solution. Either on the basis of demand commitment or on the vision of greenhouse gas reduction, the combined heat and power systems are effective. Minimizing the total generation cost of both electricity and heat grids, simultaneously, is the objective of researches in hybrid energy systems, and here, the authors use the same objective function. In this regard, heat energy systems are enjoying heat energy storage systems (HESS) as a proper tools in minimizing the total cost more. Heat energy storage system’s role in modern heat systems is undeniable, which having the active HESS units in the system would improve the system operation performance. Considering this, the authors have proposed CHP, HESS coupled to the system to model the heat and electricity systems simultaneously in the current work. To be more realistic, the heat pipelines are taking into account in the heat system model. Furthermore, combined heat and power (CHP) systems are kind of proper heat generation units to commit heat and electric loads at the same time. Using CHP systems, not only we could provide heat demands with a higher reliability, but also we could have a surplus electricity generation supply. The HESS units could do various functions in the system in which at this work it would be to compensate the heat generation.

The renewable resources are expanded to replace the power plants with high carbon intensity, such as coal plants. Gas-fired power plants are the main linkage between these two networks. Due to their characteristics, such as fast ramping rate, these plants complement the lack of renewables, and hence the intermittent nature of RES in the power system will be reflected in the gas network demand. As a solution, flexibility options, such as storage systems, bidirectional compressors, and power-to-gas (P2G) systems, are employed to cope with the imposed intermittency to the energy system. Taking into account the proposed issues, in this chapter, different types of flexibility options are firstly introduced, including their uses and mathematical models. After that, the contribution of these components in mitigating the intermittency and variability of RES is investigated based on previous projects and studies.

Because of increasing attention to environmental pollution globally, renewable energies such as wind and solar in the electricity supply have risen drastically. On the other hand, due to uncertainty in the amount of renewable energy production and the role of flexible gas power plants in compensating for the possible shortage of production of renewable power plants, both energy carriers’ consumption needs have a direct impact on each other. Therefore, to ensure efficient energy supply and optimal operation of electricity and gas networks, integrated network operation is necessary. Also, because of unbalanced consumption and the need for high investment to supply energy only for limited hours and low efficiency of equipment, demand response (DR) is more important as an effective method for reducing the cost and management of congestion. In this chapter, the types of DR and its linear and nonlinear modeling in the electricity and gas networks during the simultaneous operation of the gas and electricity networks are investigated. Finally, in order to investigate the effect of DR implementation on the simultaneous operation of electricity and gas networks in an integrated test system, DR with non-demand response was compared.

The enhancing influence level of renewable energy sources (RESs), particularly wind energy sources (WESs), leads to technical challenges in power system operation procedures, such as changing the traditional operation scheduling. Due to maintaining the power balance among generation and utilization, the outstanding facility to tackle the intermittency essence of WES is a fuel cell-based hydrogen storage system (HSS). Furthermore, providing more operational flexibility has been obtained from taking into account both energy and reserve markets. For this purpose, the current chapter presents a two-stage stochastic network-constrained market-clearing approach with the integration of fuel cell-based HSS and WES to obtain optimal scheduling of conventional units and provide energy and reserve services. The introduced structure is applied to a six-bus system to specify the applicability and implementation of the model. Numerical results denoted that the integrated fuel cell-based HSS and WES decrease the whole operating expenditure, load shedding, and wind power curtailment.

The current dependence on fossil fuel power generation and its developed infrastructure make fossil fuel still a crucial energy source. However, sustainable power generation is a critical need. The integrated power generation and CO₂ utilization process are a power-to-X system for simultaneous power and chemical production. The well-outlined benefits and the flexibility in energy and chemical conversion give this process an encouraging technical and theoretical perspective. This chapter tries to evaluate the concept of polygeneration operation for future power plants with the aim of not only minimizing emission but also sustaining profitability. It is illustrated that by applying a polygeneration configuration, developing the most efficient integration of off-gas pretreatment, utilization of electricity, and chemical production is achievable.

This chapter outlines the initial findings of a smart local energy system (SLES) demonstrator that at inception contained 1.96 MW_p of renewable generation, 24 MWh_p of electrical storage, 3.87 MW_p of EV charging, 3.49 MW_th of heat pump outputs and 36 kg/h of proton exchange membrane (PEM) H₂ electrolyser. The platform for deploying these assets was 250 homes and 40 commercial sites in England. As well as decarbonising heating, power and transport sectors, this demonstrator was intended to be collectively controlled by a virtual asset manager that could facilitate additional cost and carbon optimisation, grid services and demonstration of SLES revenue streams. Project challenges included the multi-sectoral integration (and modelling) of assets, characterising flexibility (i.e. number of cycles before failure) for thermal and hydrogen assets, local vs. global optimisation of distributed components, ownership and management of real-time data, contract formats that encouraged maximum asset flexibility, de-risking upfront investment and achieving sustainable business models.