Which is the best solar water pump?

The best solar water pump will depend on what type of a project you have. There is a wide variety of solar powered water pumps that include, submersible pumps, surface/transfer pumps, booster pumps, and sump pumps. Each project is different and it is possible that there will be several different options you can choose from. Cheap plastic or stainless pumps often have an extremely small lifespan, and will have weaker brushed motors that will not meet the needs of small or large scale applications. You will also find with cheap pumps that they often have loose wires, bad welds, leaks, and will most likely not include any parts.