Flow and head are one curve, never two independent figures
The best solar water pumps for 2026
A solar pump moves water for a pond, a trough or a garden without a mains cable, and the two figures printed on every box are the two ends of the same curve. Maximum flow is measured with no height to lift against; maximum head is the height at which the flow falls to zero. Neither is available at the same time as the other, and the useful specification is the curve or the table between them — flow at one metre, at two, at three. A pump that moves nine hundred litres an hour on the box may move a third of that up to a raised barrel. The panel requirement comes next: some pumps run directly from a panel and simply slow down when a cloud passes, others need a controller or a battery, and the two behave very differently on a changeable day. Dry-run protection is what saves the pump when the source empties, and it is either a sensor, a thermal cut-out, or nothing. Materials decide the lifetime — the impeller, the shaft, the seals — and the inlet and outlet fittings decide whether the hose you own will fit at all. We compare flow, head and the curve between them, panel requirement, dry-run protection, materials and fittings.