碳市场设计讨论专题 改善 电力 调度 机制 助力 全国 碳 市场发挥功效 Topics in Carbon Market Design Power Sector Dispatch Re and China’s National ETS Max Dupuy and Ang Li 2016 年 12 月 December 2016 2 目录 前言 . 3 什么是电力 调度 . 4 经济调度（Merit Order Dispatch ） 国际大多 数地区指导 调度的原则 4 经济调度与 排放交易有 什么关系 . 5 发电调度在 中国是怎样 运行的 . 6 中国的排放 交易与电力 调度 . 7 改善中国的 电力调度机 制 . 8 结论 . 9 Table of Contents Introduction 10 What is generator dispatch . 10 Economic dispatch The guiding principle of dispatch in most of the world . 11 What does economic dispatch have to do with emissions trading . 12 How generator dispatch works in China 12 Emissions trading and dispatch in China 13 Dispatch re in China 14 Conclusions . 15 3 前言 在国务院发布的“十三五”控制温室气体排放工作方案中提出，中国将 于 2017 年启动全国碳排放权交易市场，涵盖石化、化工、建材、钢铁、有色、 造纸、电力和航空等 8 个行业中年耗能 1 万吨标准煤以上的企业。按照“方案” 内容，几乎所有电力企业都要纳入全国碳交易市场。中国的电力行业消费了全 国 50 以上的煤炭，贡献了 40 左右的 CO2 排放，是最大的排放部门 1 ，其排 放的变化对全国达峰目标的完成与否至关重要。 与此同时，新一轮的电力行业改革也在进行中。关于进一步深化电力体制 改革的若干意见（9 号文）于 2015 年 3 月下发，同时出台的还包括关于有 序放开发用电计划的实施意见等 6 份配套文件。这些文件对具体的改革领域 提出了明确的要求。其中，9 号文中明确提出了这轮改革的关键目标，包括“ 提 高能源利用效率” 以及“ 促进节能环保” ，并且将节能减排作为了主要原则之一。 电 力 行业改革 和碳 市场建 立这 两个政 策进 程从设 计到 执行都 有着 紧密的 联 系 。 在缺乏相互协调的情况下，各自设定的政策目标可能会面临重重挑战，并限制 两个政策实际作用效果。这两个进程之间的价格信号传导被视为最为关键的联 系之一，而现行的电力调度机制可能是制约碳市场促进电力行业低碳化的障碍。 进一步放开发用电计划被视为此轮电改的核心任务之一。作为 9 号文的配套 文件之一，关于有序放开发用电计划的实施意见提出了放开发用电计划的 原则和方向。今年 7 月，发改委经济运行调节局下发的关于有序放开发用电 计划工作的通知（征求意见稿）则预示此项工作进入操作层面。 本文将向对负责设计全国碳排放交易体系的相关方和决策者们简略介绍现行 的电力调度机制及其与碳市场之间的关系 。 只 有 电力市场 改革 与碳市 场建 立有机 结合 ，才能 促进 中国的 电力 行业低 碳 化 。 本文将着重介绍改善电力调度机制与碳市场。在之后的文章中，我们将探讨碳 排放交易体系的设计与电力市场改革其他方面的结合。 1Zhao, X.L., Ma, Q., March 2015 3In the future, there may be large-scale storage of electricity, in the shape of large batteries or other s. However, although storage costs are decreasing, it is still expensive and will likely be limited, compared with the overall size of the power system, for some time. 11 Electricity grids are managed by system operators, who are responsible for maintaining near-instantaneous balance of overall supply and demand on the grid. Demand fluctuates throughout the day, as do other conditions on the grid, such as congestion of various transmission lines. Generator dispatch is the process, managed by the system operators, of deciding which generators to use to meet demand and maintaining stability of the grid. 4The system operators must make these dispatch decisions on a day-by-day, hour-by-hour, and minute- by-minute basis so that electricity demand and supply are always in balance. In recent years, system operators have begun to face a new challenge of balancing the grid with the presence of growing amounts of renewable sources of generationwind and solarthat cannot be directly controlled in the manner of a traditional coal- or gas-fired power plant. This challenge is surmountable, but requires multi-faceted solutions, including efficient approaches to dispatch, along with other technical approaches and changes to electricity pricing and other areas of power sector policy. Dispatch re in China is the subject of the current paper. Economic dispatch The guiding principle of dispatch in most of the world In North America, Europe, and most other places in the world, system operators make dispatch decisions based on the “economic dispatch” approach. The basic idea of economic dispatch is to rank each available generator by operating cost also called “short-run marginal costs” or “variable costs”. Operating cost mostly reflects fuel cost and the efficiency with which the generator converts the fuel into electricity. Where there is a carbon price, the cost of emissions is also at least partially reflected in the operating cost of each generator. According to this ranking of available generators, also known as the “merit order,” the system operator makes use of the least costly generators first. 5The system operator repeats this rcise multiple times each day in order to deal with fluctuating demand, supply, and grid conditions. The system operator may not always be able to use the least-cost generator, due to grid congestion or other changes in grid conditions, but minimization of total operating costs across generators is a key principle for operation of the grid. Figure 1 demonstrates a merit order for a given hour on a hypothetical power system. Renewable energy has zero fuel cost and zero social cost of emissions, so when it is available, it is usually ranked first in the merit order. Coal- and gas-fired generators have varying levels 4In Chinese, the word “diaodu,” literally “dispatch,” is commonly used to refer to a wide variety of system operations, including day ahead and real-time operations. We follow that usage here. 5Note that capital costs are not reflected in the dispatch ranking. The basic logic is that dispatchers are responsible for minimizing the costs of producing electricity from the set of resources that already exist. 12 of efficiency, and thus different operating costs, so have different positions in the merit order. What does economic dispatch have to do with emissions trading Carbon pricing and economic dispatch interact to support renewable generators and other relatively low-emissions generators. Because carbon costs are part of any generator’s operating costs, and because carbon emissions vary across generators, a carbon price reinforces the position of relatively-low emission resources in the merit order. Carbon pricing can sometimes cause rearrangement of the merit order in favor of relatively low- emissions generators. In addition, in the EU and US the interaction of carbon pricing and economic dispatch typically allows relatively low-emission generators to earn higher revenue in any given year. 6In turn, this provides incentive to investors to invest in more low-emissions generation capacity and to invest less in high-emission capacity. In the context of a typical competitive electricity spot market, all generators are paid the market price and the effect of implementation of a carbon price will be to increase profits for zero- emission power plants as in Figure 1. Figure 1. Carbon pricing in the context of merit order dispatch and a competitive spot market A simplified example How generator dispatch works in China In China, the power sectorincluding the approach to dispatchevolved in a way significantly different from the rest of the world. In recent decades, policymakers put great emphasis on ensuring the rapid expansion of generation capacity to meet demand for 6Where does this higher revenue come from Many parts of the US and Europe have electricity wholesale markets, in which all dispatched generators are paid the marginal cost of the last generator dispatched. In this way, a carbon price leads to higher revenues for generators that have better rankings in the merit order. For renewable generators, with near-zero marginal costs and zero emissions, higher prices mean higher revenues. 13 electricity from heavy industry. To support investment in power plants, an annual planning process was implemented with the goal of providing a stable source of revenues to generatorswhich, in practice, focused on coal-fired generation. Dispatch decisions were required to support this plan and were based on the objective of making sure each coal-fired generator gets an annually planned allocation 年度 发电量计 划 of operating hours. In short, minimizing operating costs were typically not a focus of system operators. The generators dispatched at any given moment were often not the lowest-operating-cost generators available. In past decades, the downsides were limited Because industrial demand tends to be fairly constant throughout the day, with many factories running production at a more-or-less constantly throughout the day and night, the system operators’ task of balancing the system from hour to hour was relatively straightforward and there was little need for flexibility. In short, China’s approach can be considered to have been quite successful in meeting the goal of mobilizing huge investments in generation capacity to support the development of heavy industry. This was a significant accomplishment that other developing countries have struggled to match. However, while the approach to dispatch that evolved in China may have suited China’s conditions in earlier years, it now represents significant inefficiency. China’s typical approach to dispatch is not sufficiently flexible to support the rising variability of demand due to increasing importance of non-industrial customers and supply due to growing wind and solar generation. The approach to dispatch contributes to significant curtailment of wind, solar, and hydro generators. See Figure 2. In addition, China’s typical approach to dispatch means that less efficient coal-fired power plants are often used when more efficient plants are available. As a result of these problems, power sector costs and emissions are unnecessarily high. Emissions trading and dispatch in China China’s approach to generator dispatch represents a barrier to the working of carbon pricing. In principle, carbon pricing should increase the operating cost of high-emission power plants. In other countries, this then influences the dispatch merit order, resulting in lower-emissions resources being used first. This also sends signals for more investment in low-emissions resources. But, as we have seen, in China system operators have typically not dispatched based on operating costs. This means that the economic signals associated with carbon pricing are not effectively transmitted through the power system.