Pump efficiency affects both energy consumption and solar array size. The table below shows typical best-efficiency-point (BEP) ranges for common pump types used in water systems.
| Pump type | Typical efficiency (%) | Best suited for |
|---|---|---|
| Small centrifugal surface pump | 35 – 55 | Low-head irrigation, boosting |
| Submersible borehole pump | 50 – 70 | Deep wells, high head |
| Helical rotor (positive displacement) | 60 – 75 | High head, low flow, solar VFD |
| Centrifugal multi-stage pump | 60 – 80 | Booster sets, moderate head |
| Large end-suction centrifugal | 70 – 85 | High-flow irrigation |
Note: Efficiency drops quickly away from the best-efficiency point. Always select a pump whose duty point sits near the middle of its curve.