---
title: "Types of hydropower plants by head, turbine, load"
subject: "Hydropower Engineering"
chapter: 2
key: "semester_7/hydropower_engineering:hydropower-plant-types-classification"
source: https://www.bctengineer.com/q/semester_7/hydropower_engineering/hydropower-plant-types-classification
site: BCT Engineering
---

# Types of hydropower plants by head, turbine, load

Hydropower Engineering · Chapter 2: Planning of Hydropower Projects

- Asked in: 2082 Bhadra, 2+2+2 marks
- Video: [Types of hydro power plants, Classification of Hydro power plants, #HydroPlant](https://www.youtube.com/watch?v=2Ya1i7oQphg) — Mechanical Engineering Management
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/hydropower_engineering/hydropower-plant-types-classification
- Whole chapter: https://www.bctengineer.com/md/semester_7/hydropower_engineering/chapter-2

## Question

Explain the different types of hydropower plants based on head, turbine characteristics and load characteristics.

## Short answer

By head: low (<15 m) Kaplan, medium (15-50 m) Francis, high (>50 m) Pelton. By turbine: impulse (Pelton) for high head low flow; reaction (Francis, Kaplan) for medium/low head. By load: base-load runs continuously, peaking runs only at peak hours often with storage, and pumped storage shifts energy from off-peak to peak.

## Answer

Hydropower plants are classified in several ways. Three common ways are given below.

#### 1. Based on head
| Type | Head | Typical turbine |
|---|---|---|
| Low head | below about 15 m | Kaplan, propeller, bulb |
| Medium head | 15-50 m | Francis, Kaplan |
| High head | above 50 m | Pelton, Francis |

Low-head plants use large flow and often a weir or barrage; high-head plants use small flow, long penstocks or tunnels. Some books use 30 m and 100 m as the limits.

#### 2. Based on turbine characteristics
- **Impulse turbine plants (Pelton, Turgo, cross-flow):** The water jet strikes buckets at atmospheric pressure. Used for high head and low discharge. The runner is above tail water.
- **Reaction turbine plants (Francis, Kaplan, propeller):** Water flows through the runner under pressure and the runner is completely filled; they have a draft tube. Used for medium to low head and large discharge.

Specific speed increases from Pelton to Francis to Kaplan.

#### 3. Based on load characteristics
- **Base load plant:** Runs continuously at high load factor. RoR plants and large thermal plants do this. They give firm energy.
- **Peak load plant:** Runs only for the peak hours (few hours a day). Has pondage or a reservoir; large installed capacity but low load factor. Examples: peaking RoR, storage and pumped storage.
- **Intermediate (load following) plant:** Follows the daily load change.
- **Pumped storage plant:** Takes energy off-peak to pump water up and generates in peak hours.

Selection depends on the head, discharge, system load shape and economy.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which turbines suit low head plants?
   A. Turgo only
   B. Cross-flow only
   C. Kaplan, propeller, bulb
   D. Pelton
   Answer: C. Low head uses large flow with Kaplan-type turbines. (Key point: Head classes)

2. Which is true of impulse turbines?
   A. Runner under pressure with draft tube
   B. Used for low head
   C. Runner filled completely
   D. Used for high head and low discharge; jet at atmospheric pressure
   Answer: D. Pelton-type plants use jets at atmospheric pressure. (Key point: Impulse)

3. What describes a peak load plant?
   A. Never runs
   B. Has no pondage
   C. Runs only few hours with large capacity and low load factor
   D. Runs continuously at high load factor
   Answer: C. It uses pondage or a reservoir. (Key point: Peak plant)

4. How does a pumped storage plant work?
   A. Only pumps
   B. Pumps water up off-peak and generates in peak hours
   C. Uses tide
   D. Generates always
   Answer: B. It stores off-peak energy. (Key point: Pumped storage)

## Related in Hydropower Engineering

- [Hydropower intake sketch; minimizing head loss](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Ahydropower-intake-sketch-minimise-headloss) — Hydropower Engineering, chapter 5
- [Intakes for storage plants](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Astorage-plant-intake-types-arrangement) — Hydropower Engineering, chapter 4, asked 2×
- [Top producers and early plants of Nepal](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Ahydropower-history-nepal-world) — Hydropower Engineering, chapter 1
- [Working principle of RoR, PRoR and ST plants](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Aror-pror-storage-working-principle) — Hydropower Engineering, chapter 2
- [Number and runner diameter of turbines (20 m head)](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Afrancis-turbines-number-diameter-23cumec) — Hydropower Engineering, chapter 7
- [Francis runner design (40 m head, 10 m³/s)](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Afrancis-turbine-velocity-triangle-40m) — Hydropower Engineering, chapter 7

## Related in other subjects

- [Head, specific speed and part load in turbine choice](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Aturbine-head-speed-part-load) — Power Plant Design, chapter 3
- [ROR versus PROR hydropower plants](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Aror-vs-pror) — Power Plant Design, chapter 3
- [Hydropower site power and turbine](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Ahydro-site-power-numerical) — Energy Environment and Society, chapter 3
- [Cogeneration in biomass-based power plants](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Acogeneration-biomass-plant) — Power Plant Design, chapter 1