1. What is Pumped Hydro Storage?

Pumped hydro storage is a type of hydroelectric energy storage that stores energy in the form of gravitational potential energy of water, pumped from a lower elevation reservoir to a higher elevation. It accounts for about 95% of all utility-scale energy storage worldwide.

2. How Pumped Hydro Storage Works

The system works by pumping water to an upper reservoir when electricity demand is low (and prices are cheap), then releasing it through turbines to generate electricity when demand is high.

Key components:

• Upper and lower reservoirs
• Reversible pump-turbines
• Penstocks (water conduits)
• Generator/motors
• Transmission lines

3. Key Parameters in System Design

Reservoir Capacity: Determines energy storage duration (typically 4-12 hours of full power output)

Head Height: The vertical distance between reservoirs affects power density (higher head = more energy per kg of water)

Efficiencies: Modern systems achieve 70-85% round-trip efficiency

4. Using the Calculator

Tips: Enter reservoir capacities in million cubic meters, head height in meters, and efficiency percentages. The calculator provides theoretical maximums - actual system capacity depends on many additional factors.

5. Frequently Asked Questions (FAQ)

Q1: What's the typical power output of pumped hydro plants?
A: Ranges from tens of MW to over 3,000 MW for the largest facilities.

Q2: How long does it take to switch from pumping to generation?
A: Typically 1-10 minutes, making it suitable for grid balancing.

Q3: What are the main limitations of pumped hydro?
A: Requires specific geography, high capital costs, and environmental considerations.

Q4: How does this compare to battery storage?
A: Pumped hydro has much longer duration and lifespan but requires specific sites.

Q5: What's the lifespan of a pumped hydro facility?
A: Typically 50-100 years with proper maintenance.