Some energy sources, like diesel, can be unnecessarily costly when it comes to pump operation. Fortunately, there’s a solution to this: solar energy. Solar provides reliable energy without any operating costs, making it the perfect partner for any water pumping system, whether it’s intended for water production or water distribution.

In this module, we’re going to introduce you to solar water pumping systems. First up, we’ll introduce you to solar energy in general as well as the typical performance you can expect. After that, we will take a closer look at the main advantages of solar-powered water pumping systems.

Finally, we’ll use a specific example to show how a solar-powered water pumping system can be used to great effect. So, let’s get started.

Using solar as an energy source is becoming more and more popular all over the world. It has been used for a variety of purposes including providing energy for domestic homes and commercial buildings.

Solar irradiation can reach between 600-1000W/m2 on a sunny day, but on a cloudy day, it typically ranges from 50-300W/m2.

But it’s not only the amount of sun that determines performance. The panels are also influenced by temperature. For example, when the temperature is high, the voltage drops, and while the current stays relatively constant, less power is produced.

On a perfect day, you can expect approximately 10 hours of sun. But that doesn't mean that the level of power generated will be the same for all 10 hours.

For instance, if the sun rises at 6am, the irradiation levels won’t be high enough to power the solar panels. Typically, your solar pumping system will receive the most power between 10am and 4pm when the sun is at its highest.

In terms of powering water pumping systems, solar pumping technology has increased in popularity in recent years.

Let’s take a closer look at why that is.

First of all, there’s the cost. The initial cost of solar panels has previously been quite high. But today, the price of solar panels continues to drop, meaning that the payback period is becoming even shorter than previously.

And as the power is delivered by solar, there are no operating costs, whereas a diesel generator has extremely high operating costs.

Another main advantage of solar water pumping systems is the low level of maintenance.

The only form of maintenance needed for solar panels is an occasional cleaning. A diesel generator requires a much higher level of maintenance, including needing to be refueled regularly.

A solar-powered system is environmentally friendly. One of the most obvious advantages of solar technology is that it uses clean, natural energy compared to the polluting energy from diesel generators. Solar-powered systems are the most energy-efficient solution by far.

Now that we’ve outlined the main advantages of using solar power, let’s turn our attention to how solar water pumping systems work. In this example, we’re going to use a small farm as our starting point. Our objective will be to provide water to livestock, and our pump of choice will be the Grundfos SQFlex submersible pump.

First, you must install the pump in a borehole or a well. The pump will then lift the water to a cattle trough using solar power. When the trough is full, the pump is automatically switched off by the level switch signal sent through a CU 302 control unit. However, you can also continue to pump water and simply store it in a water tank for later use.

That’s just one example of how a solar water pumping system can be used. Other possible applications include pumping water to remote homes, irrigating fields, and delivering water to rural areas which aren’t covered by grid power.

That covers the basics of solar water pumping systems.

Let’s recap the main advantages.

Solar panel prices are dropping.

And because there are no operating costs, the payback period is becoming even shorter.

Solar water pumping systems require little or no maintenance once in operation.

And finally, solar water pumping systems use clean, natural energy.