梯级互补储能对新能源的长期消纳作用分析

在碳中和目标下，我国风、光新能源装机规模将持续扩大，新能源消纳难题亟待攻克。为此，本文提出实现新能源深度消纳的梯级互补储能新思路。首先，对梯级互补储能的概念进行定义，并介绍其基本运行方式；其次，在“以水定电”模式下构建储能调度模型，分别采用模拟和优化方法进行求解；最后，分析梯级互补储能对新能源的长期消纳作用。以龙羊峡－拉西瓦梯级互补储能为实例，结果表明：（1）梯级互补储能运行效率系数（梯级水电站增发电量与泵站消纳弃电的比值）约为0.5～0.7之间；（2）梯级互补储能将新能源弃电转化为水电增量时，主要是使上级水电站发电量增大，此时下级水电站发电量几乎无变化；（3）在储能运行模式下，上级水电站通过提高自身出力，从而降低弃水风险。因此，梯级互补储能消纳新能源弃电的作用显著。

Analysis of long-term consumption effects of cascade complementary energy storage on new energies

Under the pledge of carbon neutrality, the installed capacity of wind and solar energies in China will continue to expand, thus it is urgent to solve the problem of integrating new energies into power grids. In this paper, the definition of cascade complementary energy storage and its operation mode was introduced. Based on which, the consumption effects of the cascade complementary energy storage in promoting the integration of new energies premised with known reservoir inflows were analyzed. The Longyangxia-Laxiwa cascade complementary energy storage was selected as a case study. It is shown that ratios of additional energy production of the cascade hydropower plants to energy consumption of large pump stations under simulation and optimization scenarios are 0.5 and 0.7, respectively. Without impairing downstream water use functions, energy consumption of the pump station can reach 1.9 billion kWh per year, equaling to reduce the curtailed energy of the power grid by 9%. Meanwhile, additional energy production of the cascade hydropower plants reach 1.33 billion kWh per year with an increase of 7.8%. Therefore, the consumption effect of the cascade complementary energy storage in promoting the integration of new energies is promising.