What Is the Pumped Hydro Energy Storage (PHES) Round-Trip Efficiency Calculator?
Pumped hydro stores electrical energy as gravitational potential energy in an elevated water reservoir.
How Does the Pumped Hydro Energy Storage (PHES) Round-Trip Efficiency Calculator Work?
Water is pumped uphill during off-peak hours and released through turbines during peak electricity price windows.
Pumped Hydro Energy Storage (PHES) Round-Trip Efficiency Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
\text{RTE} = \frac{E_{\text{gen}}}{E_{\text{pump}}} = \eta_{\text{pump}} \cdot \eta_{\text{turb}} \cdot (1 - \text{loss})^2
Round-trip storage efficiency accounting for pumping, generation, and hydraulic friction.
How to Use the Pumped Hydro Energy Storage (PHES) Round-Trip Efficiency Calculator
- Input upper reservoir volume, gross hydraulic head, pumping/generating efficiencies, and friction losses.
Step-by-Step Example Calculation
5 Million m³ Grid PHES Facility
Input Values:
upperReservoirActiveVolumeM3:5000000
averageGrossHeadMeters:300
pumpEfficiencyPercent:86
turbineEfficiencyPercent:89
headLossFrictionPercent:3
Worked Steps: Generates 3.56 GWh storage yield requiring 4.96 GWh pumping energy for a 71.9% round-trip efficiency.
Understanding Your Result
Reveals generation capacity in MWh, pumping energy required in MWh, and round-trip efficiency (RTE).
Factors That Affect the Result
- Penstock friction and electromechanical conversion yield typical RTEs between 70% and 80%.
When Should You Use This Calculator?
- Long-duration energy storage (LDES) planning and renewable integration studies.
Assumptions & Limitations
- Assumes constant average head level across reservoir emptying cycle.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard methodology used by US Department of Energy (DOE) and IHA.