Ultra-high-voltage electricity transmission (UHV electricity transmission) has been used in China since 2009 to transmit both alternating current (AC) and direct current (DC) electricity over long distances separating China's energy resources and consumers. Expansion of both AC and DC capacity continues in order to match generation to consumption demands while minimizing transmission losses. Decarbonization improvements will result from the replacement of lower efficiency generation, located near the coast, by more modern high-efficiency generation with less pollution near the energy resources.
Since 2004, electricity consumption in China has been growing at an unprecedented rate due to the rapid growth of industrial sectors. Serious supply shortage during 2005 had impacted the operation of many Chinese companies. Since then, China has very aggressively invested in electricity supply in order to fulfil the demand from industries and hence secure economic growth. Installed generation capacity has run from 443 GW at end of 2004 to 793 GW at the end of 2008. [1] The increment in these four years is equivalent to approximately one-third of the total capacity of the United States, or 1.4 times the total capacity of Japan. [2] During the same period of time, annual energy consumption has also risen from 2,197 TWh to 3,426 TWh. [1] China's electricity consumption is expected to reach 6,800–6,900 TWh by 2018 from 4,690 TWh in 2011, with installed capacity reaching 1,463 GW from 1,056 GW in 2011, of which 342 GW is hydropower, 928 GW coal-fired, 100 GW wind, 43 GW nuclear, and 40 GW natural gas. [3] China is the country with the largest consumption of electricity as of 2011.
China's Twelfth Five-Year Plan (covering the period 2011 to 2015) provided for the development of an ultra-high-voltage (UHV) transmission corridor to increase the integration of renewable energy from the point of generation to its point of consumption. [4] : 39–41
On the transmission and distribution side, the country has focused on expanding capacity and reducing losses by:
UHV transmission and a number of UHVAC circuits have already been constructed in different parts of the world. For example, 2,362 km of 1,150 kV circuits were built in the former USSR, and 427 km of 1,000 kV AC circuits have been developed in Japan (Kita-Iwaki powerline). Experimental lines of various scales are also found in many countries. [7] However, most of these lines are currently operating at lower voltage due to insufficient power demand or other reasons. [8] [9] There are fewer examples of UHVDC. Although there are plenty of ±500 kV (or below) circuits around the world, the only operative circuits above this threshold are the Hydro-Québec's electricity transmission system at 735 kV AC (since 1965, 11 422 km long in 2018) and Itaipu ±600 kV project in Brazil. In Russia, construction work on a 2400 km long bipolar ±750 kV DC line, the HVDC Ekibastuz–Centre started in 1978 but it was never finished. In USA at the beginning of the 1970s a 1333 kV powerline was planned from Celilo Converter Station to Hoover Dam. For this purpose a short experimental powerline near Celilo Converter Station was built, but the line to Hoover Dam was never built.
In 2015, State Grid Corporation of China proposed the Global Energy Interconnection, a long-term proposal to develop globally integrated smart grids and ultra high voltage transmission networks to connect over 80 countries. [10] : 92–93 The idea is supported by President Xi Jinping and China in attempting to develop support in various internal forums, including UN bodies. [10] : 92
China's focus on UHV transmission is based on the fact that energy resources are far away from the load centers. [4] : 39 The majority of the hydropower resources are in the west, and coal is in the northwest, but huge loads are in the east and south. [11] [7] To reduce transmission losses to a manageable level, UHV transmission is a logical choice. As the State Grid Corporation of China announced at the 2009 International Conference on UHV Power Transmission in Beijing, China will invest RMB 600 billion (approximately US$88 billion) into UHV development between now and 2020. [12]
Implementation of the UHV grid enables the construction of newer, cleaner, more efficient power generation plants far from population centers. Older power plants along the coast will be retired. [13] This will lower the total current amount of pollution, as well as the pollution felt by citizens within urban dwellings. The use of large central power plants providing electric heating are also less polluting than individual boilers used for winter heating in many northern households. [14] The UHV grid will aid China's plan of electrification and decarbonization, [15] and enable integration of renewable energy by removing the transmission bottleneck that is currently limiting expansions in wind and solar generation capacity whilst further developing the market for long-range electric vehicles in China. [15]
As of 2023, the operational UHV circuits are:
| Name (Chinese) | Type | Voltage (kV) | Length (km) | Power rating (GW) | Year Completed |
|---|---|---|---|---|---|
| Jindongnan–Nanyang–Jingmen (晋东南-南阳-荆门) | AC | 1000 | 654 | 5.0 | January 2009 |
| Yunnan - Guangdong (云南-广东) | HVDC | ±800 | 1438 | 5 | June 2010 |
| Xiangjiaba–Shanghai (向家坝-上海) | HVDC | ±800 | 1907 | 6.4 | July 2010 |
| Jinping – Southern Jiangsu (锦屏-苏南) | HVDC | ±800 | 2059 | 7.2 | December 2012 |
| Huainan–Zhejiang North–Shanghai (淮南-浙北-上海) | AC | 1000 | 2×649 | 8.0 | September 2013 |
| Nuozadu - Guangdong (糯扎渡-广东) | HVDC | ±800 | 1413 | 5 | May 2015 |
| Hami – Zhengzhou (哈密-郑州) | HVDC | ±800 | 2210 | 8 | January 2014 |
| Xiluodu - Zhejiang West (溪洛渡-浙西) | HVDC | ±800 | 1680 | 8 | July 2014 |
| Zhejiang North - Fuzhou (浙北-福州) | AC | 1000 | 2×603 | 6.8 | December 2014 |
| Huainan–Nanjing–Shanghai (淮南-南京-上海) | AC | 1000 | 2×780 | November 2016 | |
| Xilingol League - Shandong (锡盟-山东) | AC | 1000 | 2×730 | 9 | July 2016 |
| Lingzhou - Shaoxing (灵州-绍兴) | HVDC | ±800 | 1720 | 8 | September 2016 |
| Inner Mongolia West - Tianjin (蒙西-天津南) | AC | 1000 | 2×608 | 5 | December 2016 [16] |
| Jiuquan–Hunan (酒泉-湖南) | HVDC | ±800 | 2383 | 8 | June 2017 |
| Shanxi North–Jiangsu (晋北-江苏) | HVDC | ±800 | 1119 | 8 | July 2017 |
| Xilingol League - Shengli (锡盟-胜利) | AC | 1000 | 2x236.8 | August 2017 | |
| Yuheng–Weifang (榆横-潍坊) | AC | 1000 | 2×1050 | August 2017 | |
| Xilingol League–Jiangsu (锡盟-江苏) | HVDC | ±800 | 1620 | 10 | October 2017 |
| Zhalute–Qingzhou (扎鲁特—青州) | HVDC | ±800 | 1234 | 10 | December 2017 |
| Shanghaimiao–Linyi (上海庙-临沂) | HVDC | ±800 | 1238 | 10 | December 2017 |
| Dianxi-Guangdong (滇西-广东) | HVDC | ±800 | 1959 | 5 | December 2017 |
| Zhundong–Wannan (准东-皖南) [17] | HVDC | ±1100 | 3293 | 12 | December 2018 |
| Shijiazhuang–Xiong'an (石家庄-雄安) | AC | 1000 | 2×222.6 | June 2019 | |
| Weifang-Linyi-Zaozhuang-Heze-Shijiazhuang (潍坊-临沂-枣庄-菏泽-石家庄) | AC | 1000 | 2×823.6 | January 2020 | |
| Zhangbei-Xiong'an (张北-雄安) | AC | 1000 | 2×319.9 | August 2020 | |
| Mengxi-Jinzhong (蒙西-晋中) | AC | 1000 | 2x304 | October 2020 | |
| Qinghai-Henan (青海-河南) | HVDC | ±800 | 1587 | 8 | December 2020 |
| Wudongde-Guangxi-Guangdong (昆柳龙直流工程) | HVDC | ±800 | 1489 | 8 | December 2020 |
| Zhangbei-Xiong'an (张北-雄安) | AC | 1000 | 2×319.9 | December 2020 | |
| Zhumadian-Nanyang (驻马店-南阳) | AC | 1000 | 186.6 | December 2020 | |
| Yazhong-Jiangxi (雅中-江西) | HVDC | ±800 | 1711 | 8 | June 2021 |
| Shanbei-Hubei (陕北-湖北) | HVDC | ±800 | 1127 | August 2021 | |
| Nanchang-Changsha (南昌-长沙) | AC | 1000 | 2×341 | December 2021 | |
| Baihetan-Jiangsu (白鹤滩-江苏) | HVDC | ±800 | 2087 | 8.0 | July 2022 |
| Nanyang-Jingmen-Changsha (南阳-荆门-长沙) | AC | 1000 | October 2022 | ||
| Wuhan-Jingmen-Changsha (武汉-荆门) | AC | 1000 | 2x233 | December 2022 | |
| Baihetan-Zhejiang (白鹤滩-浙江) | HVDC | ±800 | 2193 | 8 | December 2022 |
| Wuhan-Zhumadian (武汉-驻马店) | AC | 1000 | 2x287 | November 2023 | |
| Fuzhou-Xiamen (福州-厦门) | AC | 1000 | 2x238 | December 2023 | |
| Zhangbei-Shengli (张北-胜利) | AC | 1000 | 2×366 | October 2024 [18] | |
| Wuhan-Nanchang (武汉-南昌) | AC | 1000 | 2x456.6 | November 2024 [19] | |
| Sichuan-Chongqing (四川-重庆) [20] | AC | 1000 | 2x658 | 24 | December 2024 |
The under-construction/In preparation UHV lines are:
| Name (Chinese) | Type | Voltage (kV) | Length (km) | Power rating (GW) | Year started |
|---|---|---|---|---|---|
| Jinshang-Hubei (金上-湖北) [21] | HVDC | ±800 | 1901 | 8 | February 2023 |
| Xaoping-Shandong (陇东-山东) | HVDC | ±800 | 926 | 8 | March 2023 |
| Ningxia-Hunan (宁夏-湖南) [22] | HVDC | ±800 | 1634 | 8 | June 2023 |
| Hami-Chongqing (哈密-重庆) [23] | HVDC | ±800 | 2290 | August 2023 | |
| Shaanbei-Anhui (陕北-安徽) [24] | HVDC | ±800 | 1069 | 8 | March 2024 |
| Aba-Chengdu East(阿坝-成都东) [25] | AC | 1000 | 2x371.7 | July 2024 | |
| Gansu-Zhejiang (甘肃-浙江) [26] | HVDC | ±800 | 2370 | 8 | July 2024 |
China is the world's leader in electricity production from renewable energy sources, with over triple the generation of the second-ranking country, the United States. China's renewable energy sector is growing faster than its fossil fuels and nuclear power capacity, and is expected to contribute 43% of global renewable capacity growth. China's total renewable energy capacity exceeded 1,000 GW in 2021, accounting for 43.5 per cent of the country's total power generation capacity, 10.2 percentage points higher than in 2015. The country aims to have 80 per cent of its total energy mix come from non-fossil fuel sources by 2060, and achieve a combined 1,200 GW of solar and wind capacity by 2030. In 2023, it was reported that China was on track to reach 1,371 gigawatts of wind and solar by 2025, five years ahead of target due to new renewables installations breaking records. In 2024, it was reported that China would reach its target by the end of July 2024, six years ahead of target.
China is the world's largest electricity producer, having overtaken the United States in 2011 after rapid growth since the early 1990s. In 2021, China produced 8.5 petawatt-hour (PWh) of electricity, approximately 30% of the world's electricity production.
In 2023, Spain consumed 244,686 gigawatt hours (GWh) of electricity, a 2.3% decline from 2022.
China is the world's largest consumer of electricity, and its demand is expected to double by the next decade, and triple by 2035. In 2010, 70 percent of the country's electricity generation came from coal-fired power plants, but the Chinese government is investing heavily in renewable energy technologies. As of 2013, 21 percent of China's electricity generation comes from renewable sources. This represents only 9 percent of overall primary energy consumption in the country. China's latest goal is to increase renewable energy to 9.5 percent of overall primary energy use by 2015. To implement China's new clean energy capacity into the national power grid, and to improve the reliability of the country's existing infrastructure, requires significant upgrades and ultimately, a smart grid.
The Southern Hami–Zhengzhou UHVDC is an ultra high-voltage direct current power transmission line from the north-west to central China.
Hydroelectricity is currently China's largest renewable energy source and the second overall after coal. According to the International Hydropower Association, China is the worlds largest producer of hydroelectricity as of 2021. China's installed hydroelectric capacity in 2021 was 390.9 GW, including 36.4 GW of pumped storage hydroelectricity capacity, up from 233 GW in 2011. That year, hydropower generated 1,300 TWh of power, an increase of 68 TWh over 2018 when hydropower generated 1,232 TWh of power, accounting for roughly 18% of China's total electricity generation.
The Sichuan-Tibet Networking Project, or Sichuan-Tibet Interconnection Project, formally referred to as the Sichuan-Tibet Interconnection Transmission and Transformation Project, HVDC Sichuan-Tibet, seeks to link the power grid of Chamdo in Tibet with that of Sichuan, thereby terminating the prolonged isolation of the Chamdo region and fundamentally addressing the critical electricity shortage and power deficiency in the southern areas of Chamdo and Garzê in Sichuan. The project spans over 1,500 kilometers, predominantly situated in high mountainous and uninhabited regions, with an average elevation of 3,850 meters and a maximum elevation of 4,980 meters, considered the most arduous power transmission endeavor in the world.
The Central Tibet Networking Project, or HVDC Central Tibet, encompasses the Central Tibet and Chamdo Grid Networking Project, along with the power supply initiative for the Lhasa to Nyingchi segment of the Sichuan–Tibet railway, commencing in Markam County of Chamdo City and concluding in Sangri County of Shannan, traversing ten districts and counties across three cities and regions. The project's overall investment amounts to around 16.2 billion RMB, encompassing 16 new and expanded substations of 110kV and above, along with 2,738 kilometers of new lines of 110kV and above. It finalized and was operational by 2018. The Central Tibet Networking Project integrates nearly 80,000 individuals from the Bomê County, Zayu County, and Mêdog County onto the primary grid, achieving comprehensive coverage of the main electricity grid in Nyingchi.
The Ngari Networking Project, or HVDC Ngari, sometimes referred to as the Ngari-Central Tibet Grid Networking Project, is a 500 kV transmission and substation initiative that commenced operations on December 4, 2020.
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