Acknowledgements：This work was sponsored partly by EPSRC (Engineering and Physical Sciences Research Council) Grant EP/L017725/1, and Grant EP/N032888/1, ATETA (Accelerating Thermal Energy Technology Adoption) project and China Scholarship Council. of Ministry of Education of China.
Economic analysis of energy interconnection between Europe and China with 100% renewable energy generation
The economic benefits of interconnecting the power grids of Europe (EU) and China (CN) were assessed considering 100% reliance on renewable energy (RE). Four different scenarios, energy storage without interconnection, installing additional renewable energy sources without interconnection, energy storage with interconnection, and installing additional RE sources with interconnection, were considered for the economic benefit analysis. A comparative study of these four scenarios was conducted to identify the best option for achieving hourly power balance. Further, sensitivity analysis was carried out to demonstrate the robustness of the results. Electricity interconnection between CN and EU decreases the annual additional costs by more than 30% when compared to the absence of interconnection, which demonstrates the necessity and benefits of CN-EU electricity interconnection.
Global Energy Interconnection, Ultra High Voltage Direct Current (UHVDC), High Voltage Direct Current (HVDC), Energy storage, Economic analysis, Energy reserve, Grid construction.
Climate change, resource scarcity, environmental pollution, and unbalanced development all pose a major challenge to the sustainable development of society. The fundamental solution is to promote global energy transformation, wherein RE and energy efficiency are the main pillars [1-3]. Increasing energy connectivity is key to implement the energy transformation [1-8]. There are several concepts relevant to energy connectivity, e.g., global energy interconnection (GEI) [3-5], which refers to “Ultra-High Voltage Grid + Smart Grid + RE”, energy internet (EI) , which focuses on the interactions between consumers, distributed generation, and smart distribution networks, and global power & energy internet (GPEI) [7, 8], which highlights the interconnection of electricity, heat, and gas networks as well as transport networks at four layers, i.e. transnational, national, city and consumer layers. CN and EU are two of the most important energy-consuming centers of the world and have different available RE sources. Electricity interconnection of the two areas could cover regions in up to eight time zones. As RE generation and demand patterns are different in different time zones, this will facilitate utilization of different renewables. Further, with the breakthrough development of UHVDC links [9, 10], which offer advantages of a large power transfer capacity over long distances with low power loss, the CN-EU electricity link has become technically feasible. Moreover, CN’s goal to export industrial overcapacity under its “he Belt and Road” Initiative coincides with EU’s goals of reducing carbon footprint and decreasing nuclear energy . Therefore, energy interconnection would be beneficial to both parties and can potentially receive policy support of both CN and EU governments. In general, as a key part of GEI, electricity interconnection between CN and EU is increasingly gaining momentum. Studies providing insights on the planning of energy interconnection between CN and EU under a high RE penetration scenario are limited. Based on the basic concept of GEI and the roadmap for its implementation [1, 3], the GEI backbone grid was launched at the Global Energy Interconnection Conference held in 2018. During this conference, two transmission corridors were proposed to achieve CN-EU energy interconnection and their development orientation and key UHVDC projects were discussed [11, 12]. In-depth research conducted by EU’s Joint Research Centre (JRC) explored three potential routes for CN-EU electricity linkage to achieve maximum RE utilization while avoiding harsh terrain . Researchers [14, 15] proposed meeting the electricity demand of all sectors in America and other 139 countries with 100% clean and renewable wind, water, and sunlight. They estimated the annual average power demand for each country and proposed promising portfolios of RE generation based on the annual energy balance of each country. However, energy interconnection among different countries was not taken into account. In all the above studies, hourly power balance was not given enough attention, which is necessary for practically matching power supply and demand due to the seasonal, weekly and daily characteristics of RE generation. Therefore, the aim of this study is to investigate whether the CN-EU electricity interconnection has economic benefits and, if so, determine the optimal capacity of the UHVDC links considering the hourly power balance during typical weeks in 2050, when the electricity systems of both CN and EU are expected to rely only on RE. In Section 2, a method for obtaining hourly power generation and supply data for CN and EU in 2050 according to the European electricity statistics of 2017 and the annual RE electricity and demand in both areas is introduced . Mixed integer linear programming (MILP) optimization models for determining the optimal additional RE, energy storage, and interconnection line capacities on the basis of the existing capacity deployed according to the annual energy balance are described in Section 3. Case studies of energy interconnection are presented in Section 4. In this study, two alternative measures to achieve hourly power balance and scenarios with and without CN-EU interconnection are compared and analyzed. Further, the sensitivity of the annual cost and installed transmission line capacity to varying per unit cost of different facilities is assessed. Finally, the conclusions drawn from the study are presented in Section 5.
received the bachelor and master degrees in Electrical Engineering from China Agricultural University, Beijing, China in 2015 and 2017, respectively. He is working towards Ph.D. degree with the University of Birmingham, Birmingham, U.K. His research interests include global power and energy internet, and optimal power flow.
received bachelor, master and Ph.D. degrees in Electrical Engineering from Southeast University, China in 1988, 1990, 1993, respectively, all in electrical engineering. He was an Associate Professor with the University of Warwick, England, U.K. He was with the China State Grid EPRI (NARI Group) on EMS/DMS advanced application software research and development from 1993 to 1998. From 1998 to 1999 he was visiting UMIST. From 1999 to 2000 he was an Alexander-von-Humboldt Research Fellow with the University of Dortmund, Germany. He is currently a Professor of Electrical Power Systems with the University of Birmingham, U.K., and he is also Director of Smart Grid, Birmingham Energy Institute and the Co-Director of the Birmingham Energy Storage Center. He has co-authored the first and second edition of the monograph Flexible AC Transmission Systems: Modeling and Control, published by Springer in 2006, and 2012. He has co-authored the book “Restructured Electric Power Systems: Analysis of Electricity Markets with Equilibrium Models”, published by IEEE Press/Wiley in 2010.