[论文解读] Storage or No Storage: Duopoly Competition Between Renewable Energy Suppliers in a Local Energy Market

Dongwei Zhao, Hao Wang+2 more|arXiv (Cornell University)|Oct 7, 2019

Smart Grid Energy Management参考文献 29被引用 4

一句话总结

本文建立了一个三阶段博弈论框架，用于分析本地能源市场中可再生能源供应商之间的双寡头竞争，探讨供应商是否应投资储能。令人意外的是，研究发现，由于未投资储能导致的更高不确定性反而可能提升利润，因为市场竞争减少；同时，率先投资储能的供应商可能获得的收益低于规避储能成本的搭便车竞争对手。

ABSTRACT

This paper studies the duopoly competition between renewable energy suppliers with or without energy storage in a local energy market. The storage investment brings the benefits of stabilizing renewable energy suppliers' outputs, but it also leads to substantial investment costs as well as some surprising changes in the market outcome. To study the equilibrium decisions of storage investment in the renewable energy suppliers' competition, we model the interactions between suppliers and consumers using a three-stage game-theoretic model. In Stage I, at the beginning of the investment horizon, suppliers decide whether to invest in storage. Once such decisions have been made, in the day-ahead market of each day, suppliers decide on their bidding prices and quantities in Stage II, based on which consumers decide the electricity quantity purchased from each supplier in Stage III. In the real-time market, a supplier is penalized if his actual generation falls short of his commitment. We characterize a price-quantity competition equilibrium of Stage II, and we further characterize a storage-investment equilibrium in Stage I incorporating electricity-selling revenue and storage cost. Counter-intuitively, we show that the uncertainty of renewable energy without storage investment can lead to higher supplier profits compared with the stable generations with storage investment due to the reduced market competition under random energy generation. Simulations further illustrate results due to the market competition. For example, a higher penalty for not meeting the commitment, a higher storage cost, or a lower consumer demand can sometimes increase a supplier's profit. We also show that although storage investment can increase a supplier 's profit, the first-mover supplier who invests in storage may benefit less than the free-rider competitor who chooses not to invest.

研究动机与目标

• 研究竞争性可再生能源供应商在本地能源市场中关于储能投资的战略决策。
• 分析储能投资如何影响双结算市场结构下的市场均衡、定价及数量投标。
• 阐明尽管成本高昂，储能投资导致更高或更低利润的条件。
• 探究一种悖论性结果：未投资储能的供应商可能因竞争减少而表现优于投资储能的供应商。

提出的方法

• 将市场建模为三阶段斯塔克尔伯格式博弈：第一阶段为储能投资决策；第二阶段为日前市场价格与数量投标；第三阶段为基于投标结果的消费者分配。
• 在第一阶段使用双矩阵博弈模型分析储能投资均衡，纳入储能成本与预期收益。
• 在第二阶段应用伯川德-埃奇沃思模型，以捕捉在容量与承诺约束下的价格-数量竞争。
• 引入实时惩罚机制，对日前承诺与实际发电量之间的差额进行惩罚，以建模市场风险。
• 基于可再生能源发电的概率分布计算预期收益，推导出均衡数量与利润的闭式表达式。
• 通过反证法与需求及成本参数的比较静态分析，推导出纯储能投资均衡存在的条件。

实验结果

研究问题

• RQ1 在竞争性本地市场中，可再生能源供应商在何种条件下选择投资储能？
• RQ2 储能投资的存在如何影响日前市场的均衡价格与数量？
• RQ3 为何尽管输出稳定化具有优势，供应商选择不投资储能反而可能获得更高利润？
• RQ4 投资储能的供应商是否可能比选择不投资的竞争对手处境更差？
• RQ5 需求、惩罚成本或储能成本的变化如何影响投资的盈利性与战略激励？

主要发现

• 出人意料的是，由于发电不确定性导致的市场竞争减少，可再生能源供应商在不投资储能的情况下反而可能获得更高利润。
• 率先投资储能的供应商可能获得的利润低于规避储能成本的搭便车竞争对手，尤其在需求较低或储能成本较高时。
• 未能履行日前承诺的惩罚成本越高，供应商的利润可能越高，特别是当该供应商避免储能并从战略不确定性中获益时。
• 较高的储能成本或较低的消费者需求可能通过减少竞争压力并促进策略性行为，反而提升供应商的利润。
• 当需求足够高时，供应商会以价格上限出价并获得正利润，此时储能投资仅在预期收益超过成本时才具有盈利性。
• 当需求较低且带储能供应商的利润为负时，不存在纯储能投资均衡，因为其总可通过不投资而改善收益。