13 Critical Points Help Design Successful Solar Pumping Systems

A correctly specified and installed solar-powered pumping solution can provide trouble-free and long-term service and excellent return on investment.

Today we’d like to talk about all the 13 critical points you should take into consideration when doing the site assessment, the first step of designing a successful solar PV Powered pumping system.

After having this information at hand, we can discuss options with solar pumping system suppliers and obtain accurate quotes.

Water Requirements:

1. Daily water requirements form the central criterion of a solar pumping system.
   For what purpose the pumped water will be used.
   e.g., Irrigation for horticultural, livestock.
2. Your daily water requirements.
   e.g., Stock water(cattle, sheep, lambs, horses, pigs), domestic water(household, house garden), farming(dairy, piggery, dip, crop spraying, firefighting).
3. Monthly or seasonal variation.
   Variations in the water demand are influenced by a season of a year. BERGEL and KACZOR, in their study covering two farms in Małopolska province, found that the demand was the highest from May to July, and the lowest from January to March.

Locations for the solar pumping system:

1. The proposed site for your solar pumping system.
2. The proposed location of the PV array.
3. Potential sources of shading.
   Avoiding any possible shading as the solar resource available at a site determines the energy output of a solar PV array installed on that site and the amount of time for which a solar-powered water pump will be able to operate on a typical day.

Water sources:

The possibility of supplying as much water to the delivery point as is needed during each period depends primarily on the availability of the water at its source. Availability may vary a lot over the year, or even between one year and another.

1. The type of water source.
   e.g., a dam, river or bore.
2. The recovery rate of the water source.
   What we really need to know is the total quantity of water that can be drawn from and how long.
3. The depth of the water source.
   The depth of the water source always changes, rise or fall. During the late winter and early spring, when snow melts and rainfall is plentiful, the water level rises. When water-loving plants start to grow in spring, or during dry summers, the water level falls.
4. The distance between the ground and the top of the water source.
   It refers to the static water level, which is the distance from the top of the ground to the water surface.

Water delivery:

1. The delivery point where pumped water will go.
   e.g., a storage dam or tank, directly to troughs, or to drip irrigation.
2. The vertical elevation between the water pump and the water delivery point.
   It refers to the static head, which is the vertical distance that the water travels. In a submersible pump, it would be the height difference between the water pump and the water delivery point. In a surface pump, it would be the height difference between the top of the water source and the water destination.
3. The length of the pipes between the pump and the water destination.
   It will be calculated as part of the dynamic head, representing the friction losses in the pipes.

Doing an accurate site assessment is critical to have a successful solar pump design and installation. It ensures the system delivers the required pumping outputs, to limit the amount of wasted energy to the least.

–Coulee Limited