Environmental Impacts and Benefits of Regional Power
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Environmental Impacts and Benefits of Regional Power Grid Interconnections for China Zhu Fahua State Power Environmental Protection Research Institute of China Environmental Monitoring General Station for Power Sector of China Prepared for the Third Workshop on Power Grid Interconnection in Northeast Asia, Vladivostok, Russia, September 30 - October 3 2003 Paper Prepared May, 2003 1. Current Status of and Prospects for China's Power Grid 1.1 The current status of the China's power grid China's power industry has entered into the era of large power networks, and power transmission technologies have also upgraded greatly with the recent rapid development and construction of these power networks. At present, there are seven inter-provincial power grids (East China, Northeast, Central China, North China, Northwest, Sichuan-Chongqing and South China—which covers Yunnan, Guizhou, Guangxi, Hainan and Guangdong) and four independent provincial power networks (Shandong, Fujian, Xinjiang and Xizang (Tibet) operating in mainland China. Large power grids now serve all cities and most villages throughout China[1], as can be seen in Figure 1. By the end of 2001, the total generating capacity in China was 338 GW (gigawatts), of which hydroelectric capacity (totaling 83 GW) accounted for 24.5%, thermal power (253 GW) accounted for 74.9%, and nuclear and other types of generation (at 2 GW or so) accounted for 0.6%. This division of capacity is shown in Figure 2. The total electricity generated in 2001 was 1,483,856 GWh (gigawatt-hours), of which thermal power supplied 1,204,478 GWh, accounting for 81.2% of total generation. Of thermal generation, 95% was from coal-fired power plants (as shown in Figure 3)[3]. China's reliance on coal-fired power has caused serious environmental problems, as will be described later in this paper. 1 [2] Figure 1: China's power grids Others Hydro 0.6% 24.5% Thermal 74.9% Figure.2: The structure of generation capacity in China as of 2001 2 Nuclear & Hydro- others electricity 1.2% 17.6% Thermal Electricity Figure 3: The structure of electricity generation in China in 2001 By the end of 2003, the total generating capacity in China is expected to be approximately 370 GW. Power supply, however, is still poor in many provinces. At present, overall, there is a slight shortage of power supply nationwide. The projected electricity demand and supply situation in 2003 in each region and province of China is shown in Table 1. Table 1: The status of electricity supply and demand by province in China, 2003 Region Provinces where Provinces where Provinces in which demand exceeds demand and supply supply somewhat supply (15) are roughly in exceeds demand balance (8) (10) North China Shanxi, Southern Beijing, Tianjing, part of Hebei, North part of Hebei, Western part of Shandong In-Mongolia Northeast Heilongjiang, Jilin, Liaoning, East part of In-Mongolia Northwest Gansu, Qinghai, Xinjiang Shanxi Ningxia Central China Henan, Chongqing, Hubei, Hunan, Jiangxi Sichuan South China Guangdong, Guangxi, Hainan Guizhou, Yunnan Eastern China Jiangsu, Zhejiang, Anhui, Fujian Shanghai Others Tibet In general, as noted above, electricity is currently in relatively short supply in 3 China at present. As shown in Table 1, there are 15 provinces in which there is lack of electricity. These provinces are found in all regions of China except the Northeast[4]. 1.2 Prospects for the development of China's power grid There is no doubt that electricity demand in China will continue to increase dramatically in the future due to the rapid pace of economic development in the country. Figure 4 shows the pattern of power industry development (generation and capacity) over the past twenty-plus years relative to the pattern of overall economic (gross domestic product, or GDP) growth[5,6,7]. 40000 35000 GDP (billion RMB) 30000 Generating Capacity (10 MW) 25000 Power Generation (100 GWh) 20000 15000 10000 5000 0 79 81 83 85 87 89 91 93 95 97 99 01 19 19 19 19 19 19 19 19 19 19 19 20 Figure 4: Comparison of trends in China's power industry development with trends in GDP, 1979 to 2002 By the year 2020, China's GDP is expected to increase by 200% over that of 2000, meaning that annual average GDP growth rates are projected to average 7.2% or so over the next 18 years. Under this projection, China's GDP in 2020 will have risen to 35,000 billion RMB. In order to meet this economic growth target, it will be necessary for China's electric power industry to maintain its recent rapid rate of development. Total nationwide electricity consumption in 2010 is projected to rise to about 2,700 billion kWh, with generating capacity increasing to about 600 GW. Total annual electricity demand in 2020 will is estimated to have grown to 4,000 billion kWh or so, with total national generating capacity reaching about 900 GW. On average 30GW of generating capacity will needs to be added each year for the next 18 years to reach these capacity goals[8]. This rate of addition is approximately twice the rate of recent capacity expansion, and is thus a great challenge for the Chinese power sector. Interconnections between large regional power grids in China, as well as interconnection between regional nets and independent provincial nets, are presently being considered and implemented. Four directional (east, west, south and north) 4 interconnections and circumjacent interconnections among nets are being constructed in order to allow power from West China to flow to the major consuming areas in the East, to allow power to be shared between North and South China during times when available capacity in one region coincides with high demand in the other, and to allow power from the central Three Gorges Hydropower project to be distributed in each of the radiation in all four directions. By the year 2005, power grid interconnection for all of China except Xinjiang, Tibet, Hainan and Taiwan will be preliminarily complete[1]. 2. Environmental Impacts of China's Power Industry 2.1 Environmental impacts power generation Power demand all over the world currently relies preliminarily on fossil fuel combustion (thermal power), as well as hydro and nuclear. The amount of electricity generated from wind, solar, tidal, and geothermal energy accounts for a very small percentage of the current total global generation. There is no doubt that large-scale power generation inevitably causes environmental impacts of varying levels of severity. Table 2 shows a subjective environmental ranking of various power-generation technologies[9]. Power-generation from solar energy, wind energy, tidal energy and biomass is renewable and sustainable. The environmental impacts of these generation technologies are relatively light. Table 2: Environmental ranking of various power-generation technologies Environmental rank (impact from least Remark to most) Solar energy Wind energy Renewable and sustainable Tidal energy Biomass Hydro Renewable and potentially sustainable Geothermal Natural gas Oil Non-renewable and unsustainable Coal Nuclear 5 Hydroelectric generation is or should be renewable as it burns no fuel and is powered by solar energy via the hydrologic cycle. Prevention of sedimentation in hydroelectric is essential if generation capacity is to be maintained. Reservoir development in which the areas flooded contain considerable biomass (forests or peat, for example), however, can lead to significant greenhouse gas emissions (methane and carbon dioxide from decaying biomass). The environmental impacts of geothermal power systems are generally easily managed (for example, through re-injection of condensates once heat has been extracted), so it makes sense to utilize this resource where it is available. Utilization of all fossil fuels is unsustainable by definition. The combustion of fossil fuels, especially coal, can produce heavy environmental impacts. Coal combustion produces smoke dust (particulate matter), sulfur dioxide, NOX, and CO2 emissions. In addition, some wastewater, as well as and fly ash and bottom ash, are also produced by coal-fired power plants. Generators can use advanced technologies and equipment to reduce dust, SO2 and NOX emissions from fossil fuel-fired power plants to minimum levels, but these technologies are generally are not widely used in China today. So far, however, power generation equipment cannot use coal without excessive CO2 production. If coal technology improves such that CO2 emissions can practically and economically be largely eliminated, or CO2 from coal-fired generation can be collected and adequately disposed of, prospects for future development of coal-fired power would improve. Nuclear power plants do not emit many air pollutants, but their operation results in the production of radioactive wastes, and pose safety problems. If the radioactive waste storage problem in China (or regionally) is solved, and if in addition “inherently” safe reactor designs are achieved, uranium mining impacts are reduced, nuclear weapons proliferation issues are fully addressed, and shipment of radioactive materials becomes safe, then prospects for future deployment of nuclear power generation would improve[10]. 2.2 Environmental impacts caused by China's thermal power plants As mentioned above, most power in China is generated in power plants burning fossil fuels, especially coal. In 2002, for example, power generated using fossil fuels in China totaled 1342 billion kWh, accounting for 81.8% of the total 1640 billion kWh of power generated in China. The key environmental impacts caused