--- title: "Pumped storage plant and benefit to Nepal" subject: "Hydropower Engineering" chapter: 2 key: "semester_7/hydropower_engineering:pumped-storage-benefit-nepal" source: https://www.bctengineer.com/q/semester_7/hydropower_engineering/pumped-storage-benefit-nepal site: BCT Engineering --- # Pumped storage plant and benefit to Nepal Hydropower Engineering · Chapter 2: Planning of Hydropower Projects - Asked in: 2075 Chaitra, 3 marks - Video: [Pumped Storage Hydropower | #3 | #LearnSomethingNew | #hindi](https://www.youtube.com/watch?v=MZW8TX80H_s) — The Smarter Things - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_7/hydropower_engineering/pumped-storage-benefit-nepal - Whole chapter: https://www.bctengineer.com/md/semester_7/hydropower_engineering/chapter-2 ## Question What do you mean by a pumped storage power plant? How can it benefit Nepal's power sector? ## Short answer Pumped storage uses two reservoirs: off-peak surplus electricity pumps water uphill; peak demand releases it to generate power. Nepal benefits by utilizing monsoon surplus, meeting evening peak, providing grid stability (frequency control), reducing dry-season imports, and supporting intermittent renewables like solar and wind. ## Answer A **pumped storage power plant** has two reservoirs at different levels. In off-peak hours (night or monsoon surplus) the reversible pump-turbine uses cheap surplus electricity to pump water from the lower to the upper reservoir. In peak hours the water is released back through the turbine to generate power. The cycle efficiency is about 70-80%. #### Benefits to Nepal - **Peak power:** It meets the evening peak with stored energy. - **Use of monsoon surplus:** Nepal has surplus RoR energy in the wet season, which would otherwise be spilled, and this can be stored. - **Grid stability:** Gives fast frequency control and spinning reserve. - **Dry season support:** Reduces the import from India and improves energy security. - **Needs less water** than a storage dam, because the same water is reused, and can be built on a hill near the load centre. - **Supports intermittent sources** such as solar and wind. - **Lower environmental effect** than a large dam. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. How does a pumped storage plant operate over a day? A. It pumps water up using cheap surplus power in off-peak hours and releases it through the turbine in peak hours B. It pumps water up during peak hours and generates during off-peak hours C. It stores river flow in one reservoir and generates continuously at constant load D. It uses two turbines in series on a single reservoir Answer: A. Surplus off-peak energy is used to pump water from the lower to the upper reservoir, and the stored water generates power at peak time. (Key point: Operating principle) 2. Why is pumped storage especially useful for Nepal's wet season? A. It removes the need for any RoR plants B. Surplus RoR energy that would be spilled can be used to pump and store water C. It increases the monsoon river flow D. It reduces sediment in the reservoir Answer: B. Nepal has surplus RoR energy in the wet season that would otherwise be wasted; pumped storage stores it for later use. (Key point: Use of monsoon surplus) 3. Which statement about a pumped storage plant is correct? A. Cycle efficiency is about 95-100% B. It needs much more water than a storage dam C. It cannot give spinning reserve or frequency control D. It needs less water than a storage dam because the same water is reused, with a cycle efficiency of about 70-80% Answer: D. Water is recycled between the two reservoirs, so little new water is needed; losses in pumping and generating give 70-80% efficiency. (Key point: Water need and efficiency) ## Related in Hydropower Engineering - [Pumped storage plant: power, turbine, setting, surge](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Apumped-storage-turbine-surge-numerical) — Hydropower Engineering, chapter 7 - [Importance of storage plants; pumped storage layout](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Astorage-importance-pump-storage-layout) — Hydropower Engineering, chapter 2 - [Development cycle; storage plant layout](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Adev-cycle-storage-layout) — Hydropower Engineering, chapter 2 - [RoR plant layouts; storage over RoR](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Aror-layouts-storage-importance) — Hydropower Engineering, chapter 2 - [Diversion type storage plant characteristics](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Adiversion-storage-plant-characteristics) — Hydropower Engineering, chapter 2 - [Institutions in Nepal's hydropower sector](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Ainstitutional-setup-hydropower) — Hydropower Engineering, chapter 1, asked 2× ## Related in other subjects - [Pumped storage plant and feasibility in Nepal](https://www.bctengineer.com/question.md?key=semester_7%2Fpower_plant_equipment%3Apump-storage-nepal-feasibility) — Power Plant Equipment, chapter 1, asked 5× - [Francis turbine in pumped storage plant](https://www.bctengineer.com/question.md?key=semester_7%2Fpower_plant_equipment%3Afrancis-turbine-pumped-storage) — Power Plant Equipment, chapter 1 - [Operation of pumped storage hydro plant](https://www.bctengineer.com/question.md?key=semester_7%2Fpower_plant_equipment%3Apump-storage-operation) — Power Plant Equipment, chapter 1, asked 2× - [When pumped storage is economically feasible](https://www.bctengineer.com/question.md?key=semester_7%2Fpower_plant_equipment%3Apumped-storage-economic-feasibility) — Power Plant Equipment, chapter 1