从战略高度看待分布式能源——解决中国未来20年低碳发展面临的重大战略问题

Looking at Distributed Energy System from a Strategic Perspective:A Solution to China's Low-Carbon Development Strategy for Next 20 Years

以冷热电联供为特色的分布式能源系统(DES/CCHP)是实现低碳发展的重要途径之一,是中国继续和完成工业化、城市化的能源供应保障,也是促进天然气产业链上、中、下游均衡、快速、健康发展,推动中国加速一次能源结构转型的动力。提高占总能耗50%的工业能效的关键,是以工业园区DES/CCHP替代分散的小锅炉。通过DES/CCHP项目可提高占总能耗30%的商住能效,根据估算,每年可有0.3×1012kW·h原用于生活热水的电耗被节省下来。另外,通过减少长距离输电设施的投资建设费用和输变电损耗,可以节省输电投资4160亿元,还可节省煤矿建设投资1500亿元。到2020年,中国每年天然气消耗量将在4000×108m3左右,如果其中2700×108m3都用于与电网调峰相结合的工业、商住DES/CCHP,粗略估算,可替代动力煤9.7×108t,仅此一项就可使全国总能效提高6.8个百分点。再加上其他措施,使总能效提高到接近目前世界平均水平(50%)是很有可能的,同时有可能使2020年中国的煤炭消耗总量降回到30×108t/a的水平。相应还可以减排二氧化碳19×108t/a,加上优化产业结构、提高建筑物和交通能效等方面的贡献,到2020年中国的二氧化碳排放量有可能回落到74×108t/a左右。天然气DES/CCHP路线在社会总投资方面也是低于"以煤为主"路线的,如果以解决中国的能效和碳减排问题为战略目标来看待和发展分布式能源系统,必须着眼于大型项目。发展DES/CCHP的制约因素不是技术和资金,而是各级政府的能源战略观念。

The distributed energy system（DES） typified by combined cooling,heating and power generation（DES/CCHP） is an important approach to developing low-carbon economy and ensuring a stable energy supply to sustain the industrialization and urbanization process in China and is also the driving force to facilitate the balanced,fast and healthy development of the upstream,midstream and downstream sectors of the natural gas industry and the restructuring of the country＇s primary energy mix.The key to raising China＇s industrial energy efficiency over 50% is to replace highly scattered small boilers with DES/CCHP built in industrial parks.Developing DES/CCHP projects can raise the energy efficiency of the commercial and residential sectors,which combined represent 30% of the country＇s total energy consumption.By estimate,0.3 × 1012kW·h of electricity originally intended for use in supplying hot water to the residential sector will be saved annually.In addition,416 billion yuan could be saved in power transmission cost as a result of the reduction in investment in long-distance power transmission facilities and in electricity loss taking place in the power transmission and transformation processes.The cost of building coalmines could also drop by 150 billion yuan.By 2020,China＇s annual natural gas consumption will reach some 4000 ×108m3.By rough estimate,if 2700×108m3 of gas is used in industrial and commercial DES/CCHP projects,which can also perform the function of peak-shaving,9.7×108t of thermal coal can be saved.This approach alone can raise China＇s energy efficiency by 6.8%.With the use of DES/CCHP,coupled with other measures,it is very likely for China to raise its overall energy efficiency close to the world＇s average level of 50% and it is also likely that China presses its coal consumption level down to 30×108t/a.China could also reduce its carbon dioxide emissions by 19×108t/a.If contributions by other measures such as optimizing the industrial structure and raising energy efficiency for buildings and the transportation sector are considered,China＇s carbon dioxide emissions are likely to drop back to some 74×108t/a by 2020.The natural gas DES/CCHP roadmap costs less than a coal-based one even in terms of total social investment.If the objective of developing DES is to resolve its energy efficiency and carbon emission problems,China must focus on construction of large projects.Technology and fund are not road blocks to developing DES/CCHP but the views of governments at all levels about energy strategy are.