How to choose a solar pump

In the previous blog, we discussed the basic principle of solar pumps and how they work. Now let us dive into what parameter you should consider while choosing the solar water pump.

The soul of the solar pumping system is a solar water pump, so selecting a good, reliable pump is a crucial step for building your system with maximum efficiency and a long life.

How many types of solar pumps are and what are they?

In the market, there are 2 types of solar pumps are:

• DC Solar pump
• AC Solar pump

DC solar pump: it uses a DC motor that works based on direct current supply (such as solar panel or battery), so it does not need an inverter.

AC solar pumps: it use an AC motor which is powered via a solar pump inverter that converts DC from solar panels to AC, so it does need an inverter.

You might be wondering what type of pump to buy, right?

That mainly depends on the Power system capacity. That is, a DC solar pump is generally used in low power capacity (around 5kW), while there are other factors such as efficiency, cost, service life, and noise that should be looked at while selecting the system. These information will help you in choosing which one to use and why.

Secondly, you should know what Pump Capacity you need. This is measured in HP. Horsepower (HP) is a unit of power, 1 HP = 746 Watt. the water required by the rate of flow and pressure requirement of the application. So what you need to do is to know the pump side by the water need and supply depth because your pump will need enough power to overcome the head pressure of the vertical column of water it moves out along with the extra power needed for the application. In practice, we consider 1HP=10000Watt. This means if your system is 3kw that you require a 3HP motor and so on.

The controller is the brain of the system that controls the pump circulation in a solar hot water system to get as much heat as possible from the solar panels, and it also protects the system in case of overheating.

Considering the peak sun hours to be 5 hours a day, we can calculate the rate of pumping in gallons per minute (gpm)

GPM = gallons per day/peak sun hours per day x  hour/60 minutes

‍Here's an example to illustrate how these calculations work:

‍Water requirements: 1500 gallons/day Peak sun hours: 5 hours/day Calculation:

1500/5 hours x 1 hour/60 minutes = 5gpm

You need a pump that operates at 5 gallons per minute to meet your water requirements.

In India, we have some well-reputed companies that manufacture solar water pumps such as Shakti Pumps, Lubi Solar, Falcon Pumps, Aquatex Solar Pumps, Waaree Solar Pump. While selecting the brand, you should know which pump you require according to your needs and then do research about the brand. Solar is a long-term investment, do it smartly and for any help don’t hesitate to contact us at support@solnceenergy.com