Energy internet in the Yangtze River Delta: opportunities, challenges, and suggestions

Abstract

Energy internet is an Internet of Things (IoT) based network, which combines the multi-energy flows and the information flows. In this review, the opportunities and the challenges posed to developing energy internet in the Yangtze River Delta are analyzed concerning detailed analysis of its advantages in various aspects and problems of its energy systems. Then the framework of energy internet in the Yangtze River Delta is constructed, according to which specific suggestions are also provided. This review is dedicated to helping the policy makers to draw the roadmap of future-oriented energy internet.

Keywords

energy internet / opportunities / challenges / suggestions / the Yangtze River Delta

Introduction

With continuous consumption of traditional fossil energy, which leads to environment deterioration, such as haze-fog issue [¹] in Northern China, it is essential to seek utilization of renewable energy in order to resolve these climate problems. Moreover, the current energy system, which integrates internet information technology, can provide a more efficient way to utilize the electric power as well as to satisfy the demand of consumers. Therein, the pattern upgrades of energy production and consumption is the key issue.

Energy internet is prone to be the future form of energy systems, which was first proposed by Jeremy Rifkin [²]. In his book, five major characteristics of energy internet are described: conversion of energy sources from fossil fuels to renewable energy, penetration to large-scale distributed generations, access to large-scale hydrogen and other energy storage apparatus, utilization of the Internet technology to upgrade the power system, and gradually transfer to electric transportation.

The Chinese government has proposed a series of policies to promote the Energy Internet development. In the “Instruction for Promoting ‘Internet+’ Smart Energy Development” [³], energy internet is regarded as a new pattern for the development of energy-based industry. It integrates the Internet into the power system, fully improving the energy production, transmission, and consumption. The main characteristics of energy internet in the instruction are equipment intelligence, pluripotent coordination, information symmetry, supply and demand dispersion, system flattening, trade open, etc. Energy internet is an important energy strategy support for China’s energy revolution, which can help to increase the integration of renewable energy and improve the efficiency of the whole system.

Recently, the concept of global energy internet (GEI) [⁴] has been advocated in China, in which the importance of power system inside energy internet is emphasized [⁵]. The GEI system, or the globally interconnected strong smart grid, adopts the ultra high voltage (UHV) as the backbone network, which dedicates to large-scale transmission, configuration, and utilization of clean energy around the world. Therefore, the essence of GEI can be summarized as UHV power network, smart grid, and clean energy. However, the importance of the natural gas system and electric transportation system is not emphasized in the GEI concept, which will be described in the framework of energy internet in the Yangtze River Delta.

In 2016, the National Development and Reform Commission (NDRC) issued the “Yangtze River Delta City Group Planning” [⁶]. The Yangtze River Delta is regarded as the commercial and scientific center of the whole country, where power generations and consumptions with advanced technologies are highly desirable. Besides promoting the development of energy internet, the upgrade and transform of the energy-based industries in the Yangtze River Delta will provide the benchmark for future-oriented utilizations in other regions. However, typical problems should still be addressed in the area of the Yangtze River Delta, such as, the shortage of resources, the climate and environment pollution, the unsuitable industrial structures. To resolve these serious problems, the construction of energy internet should be effectively promoted.

In this paper, the locational, economic and political benefits of the Yangtze River Delta are analyzed. Besides, the challenges posed to developing energy internet in the Yangtze River Delta are summarized. Furthermore, the framework for energy internet in the Yangtze River Delta and specific suggestions are detailed.

Opportunities for developing energy internet in the Yangtze River Delta

Location advantages

According to the “Regional Planning for the Yangtze River Delta” [⁷] released by the State Council in 2010, the Yangtze River Delta includes Shanghai Municipality, Jiangsu Province, and Zhejiang Province, with an area of 210.7×10³ km², accounting for 2.19% of the country’s territory, while according to the latest “Yangtze River Delta City Group Development Planning” [⁶] issued by the National Development and Reform Commission in 2016, the Yangtze River Delta city group includes a total of 26 cities of Jiangsu, Zhejiang, Anhui Provinces and Shanghai Municipality, covering an area of 211.7×10³ km².

As a whole, the Yangtze River Delta is located in the alluvial plain of the Yangtze River Estuary. In these areas, there are abundant water resources, moderate climate, and natural disasters. Therefore, the industrial development and urban construction will not be limited by natural conditions.

Moreover, the dense highway transportation networks in the Yangtze River Delta help to promote the construction of energy internet. By the end of 2017, there had been about 1.73 million new energy vehicles and 214 thousand public charging piles in China [⁸]. The top 10 provinces (municipalities) for charging piles are listed in Table 1, three of which are in the Yangtze River Delta. At present, the main service areas around the Yangtze River Delta expressway have been fully covered by charging stations, and a total of 8 DC charging piles have been reserved for each charging station [⁹]. As a result, charging can be guaranteed when driving out by new energy vehicles.

Economy benefits

As illustrated in Fig. 1, the GDP of the Yangtze River Delta from 2013 to 2017 was increased from CNY 11675 billion to CNY 17106 billion, achieving an average annual growth rate of about 9.3% during the past 5 years. Typically, the GDP of the Yangtze River Delta in 2017 accounts for 20.7% of the whole country and the annual growth rate reaches 16.2%. Consequently, the governments and industries consider the Yangtze River Delta as one of the economic centers of China.

In “Yangtze River Delta City Group Development Planning” [⁶], the economy density of the Yangtze River Delta city group will further improve by 2020, which covers 11.8% of the population and 21% of GDP on the 2.2% of the national territory area. The investment in energy is the resource-capital intensive, whose construction should be based on a flexible business model. Admittedly, the Yangtze River Delta has advantages to explore the development format of the energy internet, for example, promoting smart home in some advanced domestic communities and exploring power retailer based on high-proportion distributed energy communities.

Policy benefits

The city group of the Yangtze River Delta is in a crucial period of transformation, innovation, and development. Therefore, there exist policy benefits from the government in promoting the development of energy internet in the Yangtze River Delta and resolving key issues of energy internet construction.

From September 2016 to April 2017, Shanghai Municipality, Zhejiang, Jiangsu, and Anhui Provinces issued the“13th Five-year Plan for Energy Development” [¹⁰–¹³]. These areas in the Yangtze River Delta are trying to reduce the total energy consumption in future development.

In June 2017, the National Energy Administration announced the first 55 “Internet+”Smart Energy (Energy Internet) demonstration projects [¹⁴], of which 16 projects were demonstrated in the Yangtze River Delta (5 in Shanghai, 7 in Jiangsu, 3 in Zhejiang, and 1 in Anhui). All these demonstration projects will pave the way for the exploration of energy internet development mode in the Yangtze River Delta.

In addition, the Regional Cooperation Office of the Yangtze River Delta was recently founded in Shanghai, bringing the Yangtze River Delta regional integration into a new stage [¹⁵]. Moreover, the foundation of the Regional Cooperation Office also solves the problem of no unified administrative force in the Yangtze River Delta.

Challenges posed to developing energy internet in the Yangtze River Delta

Energy resource and power structure

It is a congenital deficiency that the fossil energy resources in the Yangtze River Delta are especially scarce. Therefore, the energy security is threatened by the external environment due to the high dependence on the resources in other regions.

The power generation in the Yangtze River Delta is dominated by thermal power, which is shown in Fig. 2. The installed thermal power capacity in 2017 is 228880 MW, accounting for 78% of the total installed capacity; the installed nuclear power capacity is 8690 MW, and the installed hydropower capacity is 17350 MW. In the Yangtze River Delta, there is no potential for hydropower development due to its limitation of natural conditions. It is observed from Fig. 3 that renewable energy power generation represented by wind and photovoltaic power in the Yangtze River Delta has developed rapidly in recent years, reaching a total installed capacity of 37440 MW in 2017. However, the proportion of wind and photovoltaic generations is still small.

High penetration of inter-regional imported electricity and peak shaving pressure

The Yangtze River Delta is a large electricity demand region and there is a high penetration of electricity imported from external regions. In 2016, the total rated capacity of feed-in HVDC is 39760 MW, accounting for 11% of the total installed capacity of the East China Power Grid, the schedule range of which covers the Yangtze River Delta. In addition, 30940 MW of electricity imported from external regions are integrated by the East China Power Grid, accounting for 13% of the highest electricity load. The imported electricity in the Yangtze River Delta is mainly hydropower, the generation of which is highly dependent upon the water conditions. In the flood season, hydropower seldom participates in the peak adjustment, and therefore, the peak shaving pressure is high. In other cases, the imported power supply adjusts frequently due to the water condition, putting pressure on unit commitment.

Isolated energy systems

At present, the power system of the Yangtze River Delta is mainly composed of 500 kV and 1000 kV backbone networks, which are interconnected between different provinces or cities. However, for the natural gas system, the provinces or cities generally have their own pipeline operators. The coupling between the natural gas system and power system relies on the gas power plant, which is mainly used for peak shaving at present. The environmental benefits of natural gas generation have not yet been exploited.

Especially, the proportion of gas and electric vehicles is still small compared to gasoline vehicles. No effective connection and interaction have been established among the transportation system, the natural gas system, and the power system. As a result, the Yangtze River Delta is weak in overall utilization and coordinated control of various energy resources.

Immature energy market

Since the start of last round of electricity reform, electricity operation had been keeping the planning mechanism due to the stagnation of electricity market construction [¹⁶]. The local governments even strengthened the distribution and intervention of annual grid-connection power which not only makes it difficult to implement the full guaranteed acquisition of renewable energy, but also inconductive to the prior generation of clean and efficient thermal power.

A new round of electricity reform is accelerating; however, the electricity market in the Yangtze River Delta is still immature. A typical case in point, Zhejiang Province is one of the pilot projects for electricity spot market construction, whose pace of electricity reform is quick in the country. Unexpectedly, the interest conflict among some parties cannot reach a compromise and it is still difficult to realize the ideal electric market. As a result, the trial operation plan of the spot market has faced the risk of delay. In Jiangsu Province, neither the spot market nor the ancillary service market was established. Building regional markets and promoting market-oriented trans-provincial and trans-regional transactions in the Yangtze Rivers till have a long way to go.

In addition, according to the preliminary plans of the pilot provinces, the main market players of the spot market are coal-fired units and gas-fired units, and accordingly, renewable energy, such as, wind power and photovoltaic will not participate in the spot market. Due to the role of maintaining the household gas supply, the gas source used for power generation is relatively unstable. Consequently, the proportion of gas units involved in the market will be small.

Framework and suggestions for developing energy internet in the Yangtze River Delta

Framework of energy internet

From the perspective of space coverage and main service objects, energy internet in the Yangtze River Delta can be divided into energy backbone network (EBN), urban energy internet (UEI) [¹⁷,¹⁸] and energy distribution network (EDN) [¹⁹,²⁰].

EDN is located on the consumer side of the energy, which mainly serves end users in a certain area and allows “plug and play” of distributed energy. EDNs are connected by the EBN, and under the regulation of market mechanism of energy internet, to achieve the flexible operation of comprehensive energy system. The scale of UEI is between EDN and EBN. As a regional energy center, the establishment of UEI in the urban area is important in urban future development. The Yangtze River Delta city group is one of the regions in China which has the most promising economy and the highest degree of openness to the outside world. Promoted by the “Development Plan of the Yangtze River Delta City Group” [⁶], the construction of UEI in the Yangtze River Delta boasts the advantages in locality and time. EBN consists of the strong smart grid and natural gas trunk pipeline networks, the main service of which is for the centralized access of large-scale power and natural gas sources, to achieve optimal allocation of large-scale and cross-regional energy. The physical architecture diagram of the energy internet in the Yangtze River Delta is depicted in Fig. 4.

EDE

EDN is a kind of integrated energy system that can efficiently integrate multi-energy forms like electricity, gas, heat, etc. in a certain region [²¹,²²]. EDN can access to EBN and realize transformations and interactions between the power system and non-electrical energy systems, which is the first step to realize the energy internet in the Yangtze River Delta.

The three major types of energy networks are outlined below.

1) Power network

EDN takes the distribution network (DN) as the backbone network of energy distribution in the region. DN in China is divided into the 110 kV high voltage distribution network, the 10kV medium voltage distribution network, and the 220V/380V low voltage distribution network, according to the voltage [²³]. EDN accesses to EBN by the high voltage DN in the 220 kV merge point and obtains large-scale new energy from the transmission network. In addition, the distributed photovoltaic power, wind power, and energy storage are connected to EDN by the medium and low voltage DN [²⁴]. Moreover, power networks can connect to natural gas pipeline networks through power to gas (P2G) station.

2) Thermal network

Since thermal energy takes liquid refrigerant as the energy carrier, it can only be transmitted effectively within 10 km and supplies the load nearby [²⁵]. Therefore, it is difficult for EBN to make full use of the thermal network to complete the resource allocation of energy. However, in the range of EDN, the thermal power plant or thermal energy station equipped with electric heat storage systems can absorb electricity from the medium and low voltage DN. In this way, the heat energy cannot only be used as short-term storage resources to consume large-scale renewable energy, but also cooperate with the power and gas network to improve the overall energy utilization efficiency in the region.

3) Natural gas pipeline network

Natural gas is normally transmitted in the form of gaseity. Its transmission process obeys the law of fluids and the transmission speed is about 10 km/h [²⁶] which is much slower than electricity. In the range of EDN, the natural gas pipelines can access DN by CCHP or power to gas (P2G). Alternatively, they can access the natural gas trunk pipeline networks by the centralized gas supply station and connecting lines to achieve cross-regional transmission and consumption of natural gas.

UEI

UEI refers to a kind of energy eco-system in the range of urban area which is densely populated and heavily loaded. It takes power network as the core, based on technologies such as power to gas (P2G), vehicle to grid (V2G) [²⁷], integrating multiple network forms like natural gas pipeline networks, thermal networks, and electrified transportation networks, to construct an open public service center and an energy management platform. UEI can improve the demand response participation, solve the high penetration of renewable energy, improve the comprehensive utilization efficiency of energy, and realize the integration of energy flow and information flow.

The electric vehicle is the key conjunction between city electrified transportation networks and DNs. Electrified transportation networks can be integrated based on EDN to establish UEI, construct energy information networks and comprehensive monitoring and management platforms, strengthen the demand side response, and improve energy utilization efficiency. The structure of UEI is displayed in Fig. 5.

1) Charging pile planning [²⁸]

Since the travel law of electric vehicles in different cities is different, there is a need to simulate the distribution of charging demand of EV in time and space.

The optimal planning model of electric vehicle charging stations should be established and their location and sizing determined.

2) Integrated demand response [²⁹]

Integrated demand response (IDR) is an important breakthrough for UEI to realize the users’ deep participation, the system regulation, and the transmission of energy market price signals. The establishment of IDR pilots in the intelligent buildings, residential areas or industrial parks can enrich the experience for UEI construction.

(1) Smart community demonstration project

On the one hand, residents can realize the synchronous management of home energy and information by the intelligent energy meter, providing accurate and reliable information to IDR. On the other hand, the public service management platform in the community helps the upper level achieve panoramic energy monitoring and flexible control of the terminal load.

(2) Smart building demonstration project

Build the demand response control system in the public building. Achieve the panoramic energy monitoring and joint optimal operation of cold, heat, and electricity by using intelligent sensors and intelligent terminals installed on major electrical equipment like air conditioning, elevators, lighting, etc.

(3) Smart park demonstration project

Implement the smart park demonstration project in the industrial zone which gathers large users. By deploying the demand response terminal equipment and control system, large users can realize the flexible load control. Moreover, the smart park can achieve the energy efficiency analysis and demand response of large users based on two-way information interaction.

EBN

The construction of EBN is the last step to realize energy internet in the Yangtze River Delta which will be a huge project. The relevant governments of the three provinces and one municipality can advance the construction pace from the following aspects:

1) Accelerating the construction of large wind farms in Jiangsu Province and sending the wind power to the EBN through UHV to improve the clean energy penetration of the Yangtze River Delta

2) Optimizing the allocation of electricity resources in the Yangtze River Delta by constructing and strengthening the EBNs, e.g. “transmission of electricity from Anhui to eastern China” [³⁰], “Sending coastal electricity in east Zhejiang to the west” [⁶], and “Jiangsu Nortel south delivery” [³¹].

3) Accelerating the construction of natural gas pipeline networks among the Yangtze River Delta city group, consequently forming the inter-provincial connecting pipelines and intra-provincial ring networks

Suggestions for developing energy internet

Based on the framework of energy internet in the Yangtze River Delta, specific suggestions are provided in order to accelerate the pace of energy internet construction.

Infrastructure construction

1) Flexible unit construction and transformation

Up to date, the power supply in the Yangtze River Delta has been dominated by thermal power. As more and more wind power, photovoltaic, and other renewable energy are connected to the power grid, the original operation mode will be reshaped and the output power will become uncertain and uncontrollable. To realize energy internet, an imperative step is to improve the flexibility and the penetration of the peak shaving of the traditional thermal power unit as is hoped.

2) Accelerating the industrialization research of P2G technology

According to the 13th Five-year Plan for Wind Power Development issued by the National Energy Administration, the installed capacity of China’s offshore wind power grid will reach more than 5000 MW by the end of 2020 [³²], of which the total installed capacity in Jiangsu, Zhejiang, and Shanghai in the Yangtze River Delta will produce 36000 MW. Consequently, the Yangtze River Delta will become the main battlefield for offshore wind power construction.

The large-scale applications of wind power with its natural characteristics determine that the wind power market must take a diversified development path. The Yangtze River Delta can directly electrolyze water to produce hydrogen (oxygen) by non-grid-connected offshore wind power [³³], exploring the diversified development mode of wind power, and giving play to the advantages of coastal wind energy resources. Hydrogen can be used in hydrogen automobile and new energy metallurgy industry while oxygen can be used in sludge treatment and middle water recycling industry, which can promote the rapid development of new power generations, new energy vehicles, recycling economy, and other industries.

3) Promoting the integration of transportation system into the power system

The integration of urban transportation system and power system in energy internet should fully consider the impact of charging/discharging behavior of electric vehicles on the DN. The charging pile coverage rate in the Yangtze River Delta needs to be further improved, from the transportation hub to the more dispersed residential areas. At the same time, charging paths and modes need to be optimized to minimize the impact of the randomness of charging and discharging on the DN.

4) Establishing the big data platform for energy interconnection

Establish the energy internet ecosystem and open-shared big data platform for energy interconnection and access real-time data from the whole chain of power generation-transmission-consumption. Qinghai Province has established the new energy big data innovation platform, which is takes the lead in the construction of the national new energy big data platform.

Residential PV has grown rapidly in the Yangtze River Delta, whose voltage is below 10 kV, while only the grid-connected distributed generation accessing to 10 kV voltage and above can be monitored in real time at present, bringing un-predictable trouble to the safe operation of the power grid. The Yangtze River Delta can follow the example of Qinghai Province to set up a big data platform, starting with data monitoring and analysis of distributed power generation. In addition, it is necessary to give full play to the good economic foundation of the Yangtze River Delta and the residents’ higher demand in quality of life to quicken the construction of smart homes, smart buildings, and smart communities, improve the utilization rate of smart meters and other terminals, and accelerate the load side data access to energy big data platform.

Energy system reform

1) Improving cyber security laws

Compared with the traditional power grid, the energy internet is regarded as ‘wider network, more extensive users, and more interaction’, which leads to prominent network security risks [³⁴]. Smart sensors in the energy internet will be in the hundreds of millions, which will lead to higher risks of information leakage of end users during information transmission and cyber attacks caused by illegally accessed components.

During the exploration of energy internet construction in the Yangtze River Delta, it is necessary to promote the legal construction of network, accelerating the development of information-driven bidirectional energy transmission mode, overcome the core problems of network security, and accumulate experience for the construction of energy internet in a wider range.

2) Accelerating market mechanism construction

An electricity market has yet to be established in the Yangtze River Delta, with only provinces such as Zhejiang exploring the spot market mechanism and Jiangsu exploring the ancillary service market mechanism. As the market mechanism continues to mature, market players will continue to increase. The game rules for renewable energy involved in the market should be considered.

Furthermore, in order to make small-scale decentralized DG participate in the market, it is necessary to conduct strategic behavior analysis for large-scale distributed subjects and propose appropriate market mechanism. Energy internet market is a process of multi-party interaction and dynamic game. How to study the complex game behavior among distributed market players based on non-cooperative game theory is the key to achieving market equilibrium and improving market competitiveness [³⁵].

3) Encouraging key technology development and promote standardization of network interfaces

It is encouraged to improve the scientific research strength of higher college and engineering laboratories in the Yangtze River Delta, enhance the independent research and development capability of energy internet core technologies, and support the development and application of key technologies and equipment such as advanced energy storage, energy conversion and demand side management.

Therefore, it is an important step to promote the standardization and modularization construction of network interface equipment, support the “plug and play” of various distributed power sources and online monitoring and control of load side data, and improve the ability of the energy internet to absorb renewable energy.

Conclusions

The energy systems have mainly experienced four stages since the Second Industrial Revolution. Energy internet is an innovative form of the energy systems in the fourth development stage.

This review analyzes the opportunities for developing energy internet in the Yangtze River Delta from the aspects of location advantages, economy advantages, and policy bonus. The challenges posed to developing energy internet are also summarized. Based on the analysis and summary of the energy system in the Yangtze River Delta, the framework for the energy internet in the Yangtze River Delta is formulated from the perspective of space coverage and main service objects. Some suggestions for developing the energy internet in the Yangtze River Delta are also provided at the end of the paper.

Energy internet is still in its infancy. The Yangtze River Delta has unique advantages to develop the energy internet, while the specific landing plan for the energy internet in the Yangtze River Delta needs to be further explored.

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