This article analyzes challenges and opportunities in the global energy Internet and interconnection. The development of the Global Energy Internet and Interconnection (GEI) is based on Ultra High Voltage AC/DC and smart grid technology, which provides a secure means in promoting clean, cost-effective and sustainable energy. An Energy Internet (EI) integrates all forms of energy based on information flow via the Internet.

In January 2011, the Energy Internet was described in the Proceedings of the IEEE. In July 2014, a plenary speech on the Global Energy Internet was delivered by Zhenya Liu, Chairman of the State Grid Corporation of China at the 2014 IEEE Power & Energy Society General Meeting; also in July 2015, the Late Breaking News Super Session on Global Energy Internet was conducted in the 2015 IEEE Power & Energy Society General Meeting.

Energy production and consumption have kept increasing as economies grow. The large-scale development and utilization of fossil energy has resulted in serious problems such as resource shortage, environmental pollution and climate change. According to BP Statistical Review of World Energy 2014 and 2013 Survey of Energy Resources by the World Energy Council, the remaining proven reserves of coal, oil and natural gas in 2013 was 891.5 billion tons, 238.2 billion tons, and 186 trillion cubic meters and can only be available for 113 years, 53 years, and 55 years, respectively, if the current rate of consumption is maintained.

The CO2 emitted by burning fossil is responsible for 56.6 percent of total greenhouse gas emissions and 73.8 percent of total CO2 emissions. The CO2 density in the air has been increased from 278ppm to 400ppm since industrialization began in 1750. The average surface temperature had risen by 0.85℃ from 1880 to 2012. If quick action is not taken, the CO2 density in the air will exceed the alarm value of 450ppm, and global temperature rise will exceed 4℃ by the end of this century.

An Energy Internet (EI) uses renewable energy as a primary energy source. This is closely connected togas infrastructure, electric transportation networks and heating systems. EI is different from the smart grid and could be regarded as the future advanced version of a smart grid. Several differences should be noted:

Smart grids are electric power networks, while EI will also include the gas network, electrified transportation systems and heating systems. 

In a smart grid, energy can only be used and transmitted in the form of electricity while in an EI, energy can be exchanged between different forms. 

In a smart grid, distributed power generation, energy storage and controllable loads are mainly controlled via a localized approach, while in the EI, they will be coordinated on a large-scale level; and the information system of a smart grid mainly adopts the conventional industrial approach but EI is based on the Internet, distributed intelligence and big data applications to enable energy coordination, which allows for multiple energy conversions and integration. 

The main challenges of the Energy Internet include highly reliable energy systems and information flows that require ground-breaking research in energy, telecommunication and data sciences. There is ongoing research to consider various internet of things scenarios and develop low-cost wide coverage communication architecture that provides information needed to achieve energy flow.

EI improves the economic efficiency and security of the energy infrastructure and supports zero-carbon solutions such as a zero-carbon building. Electric power networks and electric transportation networks can now be more closely linked because of the rapid penetration of electric vehicles. By properly coordinating a large number of electric vehicles and a large-scale distributed energy storage system, EI can mitigate the intermittency of renewable energy. Due to the widespread utilization of long-term, secure, sustainable, and environmentally friendly energy, the future electric grid must address the issues of storage and complex control.

Energy would be globally interconnected via the smart grid with Ultra High Voltage (UHV) networks as the backbone and clean energy as the main resource. GEI would connect the huge energy bases in both centralized and distributed generation at the North Pole and the Equator to deliver renewable energy such as wind, solar and marine energy to various customers worldwide.

In China, UHV technology could be a foundation for building this GEI and interconnection. The transmission distance of 1000 kV UHV AC, ±800 kV and ±1100 kV DC could reach 1,500 kilometers, 2,500 kilometers and 5,000 kilometers with a transmission power up to 5,000 MW, 8,000 MW and 12,000 MW respectively.

Europe gives an excellent example of interconnecting national energy grids across borders for mutual benefits, including: load leveling/sharing between utilities; increased system reliability; improved frequency and voltage control; deferral of additional generation; emergency options for system operators; and tapping of remote renewables.

People always look for greater reliability, reduced cost and lower pollution from energy systems. A dream to build a global energy grid would promote this vision on all of the continents. Through international cooperation, and with imagination, inspiration, investment and implementation, our global energy interconnection could be created in the foreseeable future to benefit all of mankind.