How Do I Choose the Best Solar Powered Water Pump?
How Do I Choose the Best Solar Powered Water Pump?
Buying a solar powered pump is usually a one-time investment. Therefore, you must factor in everything before buying one. Following are the factors you must consider before purchasing the best solar powered water pump:
Water storage Sizing
Choosing a suitable type of solar water pump
Solar Water Pump Sizing
Finalizing the best solar powered water pump
Step 1: Water Storage Sizing
Suppose you have a family of five living in a region where the weather is sunny only 7 hours a day. So, you must store enough water in the 7 hours in your tank for seven days. Now, let’s assume you have a well 900ft away from your home. Plus, a water tank, 90ft higher than the water level and 30ft higher from your house; what size solar powered water pump will you need?
If per person the water consumption per day is 80 gallons, multiply the number of persons with 80 gallons and then with seven days.
80 gallons x 5 persons x 7 days = 2800 gallons water storage.
Step 2: Choosing A Suitable Type Of Solar Water Pump
As discussed earlier, a surface pump can only lift water up to 20ft. Therefore, it is not suitable if you consider our example. In this case, your best choice must be the submersible solar powered water pump. It can lift water to high levels, although it is a bit expensive compared to the surface solar water pumps. On the other hand, if your requirements fit the surface water pump requirements, it is best to go for that.
Step 3: Submersible Solar Powered Water Pump Sizing
In order to meet your storage requirement, you should consider two factors:
Pumping rate – Determine how many gallons of water you require to fulfill the storage requirements.
Water Head – How high the pump needs to lift the water to store in the tank. Also, consider the friction losses in the pipe to be more accurate in your calculations.
Step 4: Pumping Rate
Assume the solar powered water pump will run for 7 hours every day (From 10 AM To 5 PM). Considering our example, the storage requirement is 2800 gallons weekly. It means 400 gallons of water every day in 7 hours (420 minutes).
So, to find the gallons per minute of your required pump, simply:
400 gallons/420 minutes = 0.95 gallons per minute or approximately 1 gallon per minute is your house requirement.
Step 5: Water Head
The solar powered water pump must lift water 90ft vertically and push 900ft horizontally since your house is 900ft away from the well. In such cases, you must consider the friction loss in a horizontal pipe.
Calculating friction is a bit complex and variates upon the pipe diameter. If the horizontal pipe has a 1ft diameter, then the friction loss is 0.3 at each 100ft distance. In simple words, the friction loss adds up to 2.7ft head in our solar pumping system. Now, we can calculate the water head for our solar powered water pump.
Water Head = Vertical Head + Frictional Loss
= 90ft + 2.7ft
= 92.7ft.
Step 6: Finding The Best Solar Powered Water Pump For Your House
After combining all pieces of data, we concluded that we need a submersible solar powered water pump with a 1 GPM (gallons per minute) pumping rate. Plus, we calculated the 92.7ft water head. Now, we can easily find a suitable submersible water pump because, with each pump, there will be a chart showing these two data pieces. So, calculate your requirements and choose the best solar powered water pump for your house or agriculture.
Step 7: Choose The Best Solar Pump Inverter For Your Solar Pumping System
There are various different solar pump inverter brands in the solar market, it will be great if you can choose and buy efficient MPPT VFD solar pump inverter for your solar pumping system, which from Top solar inverter manufacturer. Normally the sizes of solar pump controller should be same or higher than the power (kw) of pump. For example, if you are using three phase 7.5hp solar pump, then you should choose three phase 7.5hp solar pump controller (or 3 phase solar pump controller which power is higher than 7.5hp)
Step 8: Add And Install AC Line Reactor For Your Long Distance Solar Pump System
When the distance from solar pump to solar water pump controller is over 50 meters, then we suggest installing AC line reactor for solar VFD, when distance is over 100 meters, then we strongly suggest. Installing line reactor for solar pump inverter can prolong the life time and improve the working performance of long distance solar pump system.
