English | 中文
 
Your position: Home > GEI:How much do you know? > Details [Return]

CAN WE BUILD GLOBAL ENERGY INTERCONNECTION

Font Size: Large Medium Small | Default
[Source]: GEIDCO  [Date]: 2016-04-23

IT IS IN LINE WITH THE BASIC LAW TO CONSTRUCT GLOBAL ENERGY INTERCONNECTION

In line with the energy development law.

The global energy landscape is continually undergoing a general shift from high carbon to low carbon, from low efficiency to high efficiency, and from local balance to optimized allocation of wider scope. The establishment of global energy interconnection can promote cleaner and more efficient energy development, allocation and utilization in a larger scale, in line with the general trend of energy development.

In line with the grid development law.

In general, the world grid's voltage level gets higher, the networked scale gets bigger, and automation gets stronger. Grid is no longer small-scaled or just interconnected in big scale; it is strong and smart. Global energy interconnection integrates new technologies like UHV and smart grid, enabling the integration and interconnection of grids around the world as an advanced formation of the robust smart grid.

In line with the common interest of humankind.

The core target to build global energy interconnection is to develop clean energy, which is inexhaustible. However, this common wealth of the mankind cannot be stored in large scale and can its value only be delivered once developed and used. The development and utilization of clean energy brings little ecological impact, able to fundamentally solve the problems of climate change and energy supply. The construction of global energy interconnection bounds regions and countries where clean energy is developed, transmitted or consumed, which facilitates the mutual, harmonious and sustainable development of the world.

LARGE-SCALE GRID INTERCONNECTION BECOMES AN IMPORTANT DIRECTION FOR DEVELOPMENT

Grid development has economies of scale. Large-scaled grid interconnection is the global trend. Right now, there are several interconnected power grids in China, North America, Europe and Russo-Baltic Sea region.

Interconnected grids in China: all grids are connected nationwide except Taiwan. In 2020, there will be UHV synchronous grids in North, East and Central China, covering an area of 2.68 million square kilometers with an installed capacity of 670GW.

Interconnected grids in North America: there are four synchronous grids distributed in eastern North America, western North America, Texas and Quebec. The one in eastern North America alone covers 34 states in the US and 12 federal districts in Canada, with an area of 5.2 million square kilometers and an installed capacity of 880GW.

Interconnected grids in Europe: there are 5 transnational synchronous grids separately in continental Europe, Northern Europe, the Baltic Sea, Britain and Ireland. The synchronous grid in continental Europe covers 25 countries, with an area of 4.5 million square kilometers and an installed capacity of 820GW.

Interconnected grids in Russo-Baltic Sea region: it's the most geographically extensive synchronous grid in the world, covering 13 countries and stretching across eight time zones of Eurasia, with an area of 23 million square kilometers and an installed capacity of 200GW.

UHV TECHNOLOGY IS READY

UHV transmission technology has prevailing advantages.

UHV is transmission technology with 1000kV (or above) AC and ±800kV (or above) DC. Compared with 500kV DC transmission, UHV has larger transmission capacity over long distances with little line loss and less corridor land use.

AC transmission: The transmission capacity of UHV AC is 4 or 5 times of that of 500kV AC. The transmission distance can be doubled or even tripled while the line loss reduces to one quarter or one third. The corridor width unit capacity is as much as one third or half.

DC transmission: the DC transmission capacity at ±800kV and ±1100kV is 2-3 times and 4-5 times of that at ±500kV respectively, while the transmission distance is twice or 2-3 times. The line loss reduces to half and one quarter with 37% and 30% corridor width unit capacity respectively.

Many countries are accelerating UHV development. Since 1960s, the former Soviet Union, Japan, US, Italy have been coming up with the idea to develop UHV transmission technologies, and carried out planning, design, testing and equipment development. In recent years, China has made breakthroughs in UHV, grasping key technologies in this regard, accomplishing UHV R&D system including UHV AC and DC test bases, and conquered difficulties like electromagnetic environment and overvoltage. Now the standard AC/DC systems have been formulated and system UHV AC/DC key equipment and components, such as large-capacity UHV transformer, electric reactor, and converter valve, have been developed. China has successfully put 3 AC and 4 DC UHV projects into operation since 2009, with an accumulative transmission capacity of 360TWh. Right now, another 4 AC and 5 DC UHV projects are under construction. India and Brazil are constructing their UHV DC projects.

SMART GRID TECHNOLOGIES ARE ACCELERATING THEIR APPLICATION

Many countries pay close attention to smart grid development. Smart grid has become a national strategy in China, US, EU, Japan and Korea. These countries are actively making their smart grid development route in accordance with their national realities. Policy incentives, standard formulation, project demonstration and other measures have been taken to speed up smart grid development. In recent years, China has make all-round breakthroughs in all sectors, including, power generation, transmission, transformation, consumption and dispatching. It tackled down key technologies like coordinated and optimized control of new energies and flexible DC transmission. Smart dispatching support system and EV charging and battery swapping devices have been developed. China has accumulatively built 305 pilot projects in 32 categories, put 2,064 66-750kV smart substations into operation and deployed more than 290 million smart meters since 2009. Priorities in smart grid construction differ in US, EU, Japan and Korea. Important progress has also been made in distributed generation integration, demand response and user interaction.

WORLD CLEAN ENERGY DEVELOPS RAPIDLY

Rapid technological innovation. Wind power technology has been progressing so rapidly that the maximum single unit capacity has reached 8MW. The adaptability and generation efficiency of wind turbines are enhanced as well. The efficiency is increased by 15% -20%. Improved wind power prediction precision is now over 85%. As for substantially upgraded solar power generation, the conversion efficiency of crystalline silicon is 20%, that of thin-film cell is 15% and that of perovskite solar cell is 19.6%, which is expected to reach 50% in the future. The conversion efficiency of solar thermal generation can be increased to 30%.

Large development scale. From 2000 to 2014, the global installed capacity of wind power has gained 20 times while that of solar energy has gained 117 times. As of the end of 2014, the global installed capacity of wind power and solar generation was 370GW and 190GW, 6.2% and 3.2% of the total amount respectively. Economic efficiency has been enhanced significantly. Since 1980, cost for wind power generation has been lowered by 90% and that of PV generation keeps declining as well. For example, the price of PV modules was 2,000 US dollars per kW in 2009 and 600 US dollars per kW in China, lowered by 70%. The investment of PV stations has been reduced from 4,000 US dollars per kW to 1,400 US dollars per kW. The cost for clean energy generation will continue to be lower compared with that of fossil energy in the next 10 to 15 years.

The construction of global energy interconnection conforms to the common interest of the mankind and the development law of world energy and electric power industry. Relevant technologies, such as UHV, smart grid, and clean energy becomes increasingly mature. The transnational and transcontinental power grids constructed or to be constructed will become an important part of the global energy interconnection. Based on the practices in China and from the world, specially the development of new technology, it is feasible to construct the global energy interconnection.