Why are Solar Water Pumps not specified in Horsepower, Watts or Kilowatts?
Although solar pump motors and controllers have nominal power ratings, the power at which solar pumps operate are variable. This depends on the solar array size, and time of day ( sun radiation intensity varies over course of the day), and factors such as temperature, pump geometry and dynamic head of the application.
It is therefore not possible to make direct comparison between conventional electric pumps and solar pumps, in terms of horsepower or Kw rating. A quotation request to replace an xxx KW electric pump with a solar pump is generally not possible, unless the required pumping parameters are specified. ( volume per day and pumping head)