1. What is Pumped Hydro Efficiency?

Pumped hydro efficiency measures the ratio of energy output to energy input in pumped-storage hydroelectric systems. It quantifies how effectively the system stores and recovers energy, typically ranging between 70-85% for modern facilities.

2. How Does the Calculator Work?

The calculator uses the basic efficiency formula:

Where:

• \( \eta \) — System efficiency (decimal)
• \( E_{\text{out}} \) — Energy output (kWh)
• \( E_{\text{in}} \) — Energy input (kWh)

Explanation: This simple ratio shows what percentage of the input energy is successfully recovered as output energy during the storage cycle.

3. Importance of Efficiency Calculation

Details: Efficiency calculations are crucial for evaluating the economic viability of pumped hydro storage projects, comparing different energy storage technologies, and optimizing system operations.

4. Using the Calculator

Tips: Enter both energy values in the same units (kWh recommended). Ensure measurements are taken over the same complete charge-discharge cycle for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: What is typical efficiency for pumped hydro?
A: Modern systems typically achieve 70-85% round-trip efficiency, with some advanced designs reaching up to 87%.

Q2: Why isn't efficiency 100%?
A: Energy losses occur due to turbine/generator inefficiencies, pipe friction, evaporation, and electrical conversion losses.

Q3: How does this compare to battery storage?
A: Pumped hydro generally has lower efficiency (70-85%) than lithium-ion batteries (85-95%) but offers much larger scale and longer duration storage.

Q4: Can efficiency vary over time?
A: Yes, efficiency can decrease with equipment wear, sedimentation, or changes in water temperature/viscosity.

Q5: How is this different from energy density?
A: Efficiency measures energy recovery, while energy density measures how much energy can be stored per unit volume/mass.