Find the right solar pump for your well
Enter your target flow and total dynamic head to compare Spin Pumps models against real pump curve data. This tool provides an estimated recommendation. For final sizing, Spin Pumps can verify your well depth, static water level, drawdown, pipe friction, tank elevation, and solar array requirements.
Need help calculating Total Dynamic Head?
Pump Selection Tool Input Guide
Use the table below to gather the information needed for the pump selector. The more accurate your inputs are, the more accurate the pump recommendation will be.
| Input Needed | What It Means | How to Find or Estimate It | Why It Matters |
|---|---|---|---|
| Total Dynamic Head Feet |
The total lift the pump must overcome, including water level, elevation rise, and friction loss from pipe. | Start with the pumping water level, then add elevation gain from the well to the tank. Add extra allowance for long pipe runs, small pipe, elbows, and fittings. | This is the most important number in pump selection. A pump must be able to produce the desired flow at this head. |
| Target Flow Rate GPM |
The gallons per minute you want the pump to produce. | Estimate based on daily water demand divided by the number of useful pumping hours per day. | A pump that is too small may not keep up. A pump that is too large may overpump a weak well or operate inefficiently. |
| Static Water Level Feet below ground |
The depth from ground level to the water surface when the well is not being pumped. | Check the well log, measure with a water level meter, or ask your well driller. | Static water level helps estimate lift, but the pump should usually be sized closer to the pumping water level. |
| Pumping Water Level / Drawdown Feet below ground |
The water level in the well while the pump is running. | Use pump test data if available. If unknown, allow a safety margin below the static water level, especially in low-producing wells. | This gives a more realistic head requirement than static water level alone. |
| Tank or Discharge Elevation Feet above wellhead |
The vertical rise from the wellhead to the tank, trough, pressure tank, or discharge point. | Estimate the height difference between the well and the final water outlet. For uphill pumping, include the full rise. | Water pumped uphill adds directly to the head the pump must overcome. |
| Pipe Length and Pipe Size | The total length and diameter of the pipe between the pump and the discharge point. | Measure or estimate the total pipe run. Include vertical drop pipe, underground line, and any long horizontal runs. | Long pipe runs and smaller pipe create friction loss, which increases total dynamic head. |
| Daily Water Demand Gallons per day |
The total amount of water needed each day. | For livestock, multiply the number of animals by estimated gallons per head per day. For homes or irrigation, estimate based on normal daily use. | Daily demand helps determine the minimum flow rate and solar pumping capacity needed. |
| Well Yield GPM |
The amount of water the well can safely produce without being overpumped. | Use pump test data, driller records, or observed recovery rate. If unknown, be conservative. | Selecting a pump with too much flow can draw the well down too far and cause system problems. |
| Power Type | The type of power available or preferred for the system. | Choose DC-only for simple solar-direct systems, or AC/DC hybrid if you want solar with generator or grid backup capability. | Power type determines which pump models and controllers are appropriate. |
| Pump Type | The pump construction or hydraulic design style. | Use displacement pumps for low-flow/high-head applications, impeller pumps for higher flow, and high-speed models when the application fits their curve range. | Different pump types perform better in different head and flow ranges. |
Important Sizing Note
This selection tool provides an estimated pump match based on pump curve data. Final pump selection should account for static water level, pumping water level, drawdown, pipe friction loss, elevation change, available solar power, and well yield. If you are unsure about any input, contact Spin Pumps for help verifying the system design.