Energy Sectors Integration and Impact on Power Grids

Introduction

Historically, energy sectors such as electricity, gas, and heating/cooling have functioned independently. However, the integration of energy sectors (ESI) has emerged as a critical strategy to facilitate this transition. ESI promotes synergy among these sectors, thereby advancing decarbonization efforts and significantly reducing CO2 emissions. The primary drivers of ESI are threefold:

1. It contributes to carbon reduction by integrating renewable energy sources to replace or complement fossil fuels, thereby diminishing overall emissions.
2. ESI enhances grid reliability by providing multiple energy pathways and enabling partial system operation during disruptions.
3. It improves economic and energy efficiency by reducing capital expenditures on infrastructure and optimizing energy utilization, particularly with intermittent renewable sources.

This report delves into the technical, business, economic, and regulatory issues associated with ESI and evaluates cutting-edge research from various countries. The TB aims to bridge the gap between academic studies and ESI industry practices and identify key issues that require future attention. With 23 members from 14 countries, WG C1.47 conducted a comprehensive global investigation to determine the current state of ESI and its effects on power grids. The scope of this TB encompasses the following:

1. Identifying the technical, business, and institutional challenges and benefits of energy sector integration at the transmission grid level.
2. Reviewing methodologies and technologies related to modeling, operation, market analysis, and planning for multiregion-level ESI.
3. Summarizing the lessons learned and best practices in energy sector integration.
4. Proposing policy and market regulation suggestions to advance ESI at the transmission grid level.

Structure of TB

Chapter 1: The opening chapter includes the background, definition, scope, and aim of the TB.

Chapter 2: This chapter provides a comprehensive literature review of energy sector integration. In chapter 2.1, energy conversion technologies for energy sector integration are summarized from the power-to-X (including power-to-gas, power-to-heat, power-to-cooling, and power-to-transport) and gas-to-X (including gas-to-power, gas-to-heat, combined cooling heat and power plants, and combined heat and power plants) perspectives. Chapter 2.2 introduces the current status of energy sector integration in different countries.

Chapter 3: This chapter analyzes the impact of energy sector integration on the power transmission system. Chapter 3.1 examines the opportunities and challenges for power transmission systems resulting from the integration of multiple energy sectors from various perspectives. Chapter 3.2 discusses the implications for transmission system planning, and chapter 3.3 addresses the impacts on transmission system operation. Chapter 3.4 investigates the effects from a multienergy coupling market perspective, taking into account privacy-preserving issues.

Chapter 4: This chapter introduces a universal modeling method for multienergy systems from two distinct yet interconnected levels. The first level is the energy hub layer. At this level, we focus on developing models that describe the processes for converting between different forms of energy within a hub. The second level is the network layer. Here, the objective is to model the interconnections and coupling between different energy hubs. Following chapter 4.1 on two-level modeling, chapter 4.2 presents a general multienergy system planning method that addresses the strategic design and optimization of these systems for future development. Chapter 4.3 introduces a method for simulating the operation of multienergy systems, including district-level operation, regional-level operation, and multiregional-level operation. Finally, chapter 4.4 discusses how multienergy systems can participate in market clearing and bidding processes, offering a comprehensive view of how these systems interact with energy markets to ensure efficient and competitive operation.

Chapter 5: This chapter reviews software designed for power system planning that considers energy system coupling in power system planning, including EnergyPRO, EnergyPLAN, PLEXOS, GTEP, IESP, Calliope, SAint, Artelys Crystal Super Grid, and PowSyBl. Notably, most software is not designed especially for power system planning and is usually focused more on planning the entire energy system. Only some software programs contain all the power system planning functions, while others provide power system reinforcement suggestions according to the optimization of coordination between different energy sectors.

Chapter 6: This chapter demonstrates the best practices of power system planning considering energy sector coupling. The cases cover systems in China, Italy, the UK, the U.S., and Australia.

Chapter 7: This chapter outlines the main barriers to ESI and provides recommendations for future work.

Conclusion

The key findings of the TB are summarized as follows:

• Current energy sector integration technologies are categorized as power-to-X and gas-to-X. Prominent technologies include gas-fired power generation (gas-to-power), power-to-gas, electric vehicles (power-to-transport), and electric heating (power-to-heat).
• Integrating multiple energy sectors can increase power system flexibility and reliability while reducing economic and environmental costs. However, it may also increase complexity in investments, operations, data sharing, and market structures among different energy sectors.
• Energy sector integration modeling is often depicted through energy conversion processes using energy hubs and their interconnections, which can be utilized in planning, operation, and market optimization problems.
• Best practices from China, Italy, the UK, the US, and Australia demonstrate that ESI significantly improves flexibility, manages uncertainties, reduces costs, and better accommodates renewable generation. These practices also underscore the importance of addressing market and policy issues in ESI.
• The main barriers to fully integrating multienergy coupling into power systems include fragmented institutional and market structures, increased system complexity that heightens the risk of cascading failures, the need for multidisciplinary expertise, and the lack of standardized guidelines for modeling and optimization.

A number of research gaps in integrated energy systems that should be addressed in the future are also summarized:

• Development of methods and tools for the modeling and simulation of integrated energy systems.
• Design of market mechanisms and development of clearing models.
• Creation of standard test networks for case studies and model validation.
• Establishment of assessment criteria for quantifying the interdependencies and overall performance of integrated energy systems.
• Development of professional and comprehensive software for integrated energy system planning and simulation.