功能更好的碳市場.pdf

碳市場設計討論專題 改善 電力 調度 機制 助力 全國 碳 市場發揮功效 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 目錄 前言 . 3 什么是電力 調度 . 4 經濟調度（Merit Order Dispatch ） 國際大多 數地區指導 調度的原則 4 經濟調度與 排放交易有 什么關系 . 5 發電調度在 中國是怎樣 運行的 . 6 中國的排放 交易與電力 調度 . 7 改善中國的 電力調度機 制 . 8 結論 . 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 在國務院發布的“十三五”控制溫室氣體排放工作方案中提出，中國將 于 2017 年啟動全國碳排放權交易市場，涵蓋石化、化工、建材、鋼鐵、有色、 造紙、電力和航空等 8 個行業中年耗能 1 萬噸標準煤以上的企業。按照“方案” 內容，幾乎所有電力企業都要納入全國碳交易市場。中國的電力行業消費了全 國 50 以上的煤炭，貢獻了 40 左右的 CO2 排放，是最大的排放部門 1 ，其排 放的變化對全國達峰目標的完成與否至關重要。 與此同時，新一輪的電力行業改革也在進行中。關于進一步深化電力體制 改革的若干意見（9 號文）于 2015 年 3 月下發，同時出臺的還包括關于有 序放開發用電計劃的實施意見等 6 份配套文件。這些文件對具體的改革領域 提出了明確的要求。其中，9 號文中明確提出了這輪改革的關鍵目標，包括“ 提 高能源利用效率” 以及“ 促進節能環?！?，并且將節能減排作為了主要原則之一。 電 力 行業改革 和碳 市場建 立這 兩個政 策進 程從設 計到 執行都 有著 緊密的 聯 系 。 在缺乏相互協調的情況下，各自設定的政策目標可能會面臨重重挑戰，并限制 兩個政策實際作用效果。這兩個進程之間的價格信號傳導被視為最為關鍵的聯 系之一，而現行的電力調度機制可能是制約碳市場促進電力行業低碳化的障礙。 進一步放開發用電計劃被視為此輪電改的核心任務之一。作為 9 號文的配套 文件之一，關于有序放開發用電計劃的實施意見提出了放開發用電計劃的 原則和方向。今年 7 月，發改委經濟運行調節局下發的關于有序放開發用電 計劃工作的通知（征求意見稿）則預示此項工作進入操作層面。 本文將向對負責設計全國碳排放交易體系的相關方和決策者們簡略介紹現行 的電力調度機制及其與碳市場之間的關系 。 只 有 電力市場 改革 與碳市 場建 立有機 結合 ，才能 促進 中國的 電力 行業低 碳 化 。 本文將著重介紹改善電力調度機制與碳市場。在之后的文章中，我們將探討碳 排放交易體系的設計與電力市場改革其他方面的結合。 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 發電量計 劃 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.