Renewable energy generations and energy storage are playing increasingly important roles in serving consumers in power systems. This paper studies the market 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 (containing many days), suppliers decide whether to invest in storage. Once such decisions have been made (once), 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 in the local energy market, 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 in storage.

中文翻译：

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存储或不存储：本地能源市场中可再生能源供应商之间的双头垄断竞争

可再生能源发电和储能在为电力系统消费者提供服务方面发挥着越来越重要的作用。本文研究了当地能源市场中带或不带储能的可再生能源供应商之间的市场竞争。储能投资带来​​了稳定可再生能源供应商输出的好处，但也导致了大量的投资成本以及市场结果的一些令人惊讶的变化。为了研究可再生能源供应商竞争中储能投资的均衡决策，我们使用三阶段博弈论模型对供应商和消费者之间的相互作用进行建模。在第一阶段，在投资期的开始（包含许多天），供应商决定是否投资存储。一旦做出这样的决定（一次），在每天的日前市场，供应商在第二阶段决定其投标价格和数量，消费者据此决定在第三阶段从每个供应商处购买的电量。在实时市场中，如果供应商的实际代数达不到他的承诺，供应商就会受到惩罚。我们刻画了当地能源市场第二阶段的价格-数量竞争均衡，我们进一步刻画了第一阶段的储能投资均衡，包括售电收入和储能成本。与直觉相反，我们表明，由于随机能源发电下市场竞争的减少，与有存储投资的稳定发电相比，没有存储投资的可再生能源的不确定性可以导致更高的供应商利润。模拟进一步说明了市场竞争的结果。例如，对不履行承诺的更高惩罚、更高的存储成本或更低的消费者需求有时会增加供应商的利润。我们还表明，虽然存储投资可以增加供应商的利润，但投资存储的先发供应商可能比选择不投资存储的搭便车竞争对手受益更少。