Enhancing Flexible and Sustainable Operation of RoR hydro Plant using Battery Energy Storage

Run of River (RoR) hydro power plants generally have limited flexibility in operation. In the North Indian state of Uttarakhand, the RoR hydro power plants typically operate for base-load during monsoon and provide few hours of peaking during lean-discharge periods. The low level of flexibility in generation (due to very nature of these plants) is also augmented by environmental impacts like silting that causes wear and tear of the hydro plant machinery, particularly for old plants in the upper Ganga River basin. Apart from the technical issues, these plants also face limited revenue generation opportunities due to fixed long-term power purchase agreements which reduces their range of commercial operation. Energy storage integrated with RoR hydro plants can augment the flexible operation of such plants and can also provide opportunities for revenue generation from ancillary services like frequency regulation and others. The co-location and operation of battery storage with RoR hydro plants can provide both agility and complement the grid-stabilization and inertia support characteristics of hydro power plants for a stable power grid operation. The case of a legacy RoR hydro plant in the upper Ganga basin in the state of Uttarakhand has been taken and evaluated for integrated operation with a battery energy storage system. The analysis has been performed for a year-long period and the battery operation in conjunction with the plant has been studied in detail. The charge/discharge operation of the battery for load variation and year-wise changes in power exchange or utility grid prices has been analyzed and the maintenance shut-down schedule of the hydro plant has also been accounted for. The overall cost of energy of the proposed combination has been evaluated and a case has been presented for combined operation of energy storage with RoR hydro plants.