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31 May 2024

Solar Pumps Illuminated: Harnessing the Power of the Sun for Efficient Water Solutions

In the realm of sustainable water solutions, solar pumps stand out as a beacon of innovation and environmental stewardship. Harnessing the power of the sun, these systems offer a compelling alternative to traditional water pumping methods. In this article, we delve into the intricacies of solar pump technology, exploring key components and considerations that can optimize efficiency and performance.

1. Low Voltage Pumps:

Energy efficiency lies at the heart of solar-powered water pumping systems, and low-voltage pumps play a pivotal role in this regard. By operating at lower voltages, these pumps minimize the number of panels required to operate a deep well pump, making them the ideal solution for solar applications.

Solar-Powered Water Pumps:

  • These pumps operate by converting sunlight into electrical energy through photovoltaic (PV) panels.
  • The generated energy powers an electric motor, which drives the pump.
  • Depending on the water source depth, solar pumps can be either:
    • Surface Models: Use centrifugal pumps for shallow sources.
    • Submersible Models: Employ submersible pumps for deeper boreholes or wells.

The Role of Low Voltage Pumps:

  • Energy Efficiency: Low voltage pumps operate at reduced voltages, minimizing the quantity of panels required and results in less un-used wattage.
  • Maximizing Output: Despite the lower voltage, these pumps efficiently lift water, By using brusless direct current motors that operate at an RPM range of 4000 to 6000
  • Optimizing Solar Pump Systems: By using low voltage pumps, we enhance the overall efficiency of solar water pumping systems.


  • Reduced Energy Costs: Less photovoltaic (PV) Panels translates to cost savings.
  • Sustainability: Solar-powered systems reduce reliance on conventional electricity or diesel.
  • Environmental Impact: Minimized energy usage contributes to a greener footprint.

2. Cable Sizing for Solar Pumps:

Effective cable sizing is crucial for ensuring the seamless operation of solar pump installations. By understanding these key principles, you can ensure optimal performance and longevity for your solar pump system.

Voltage Drop Considerations:

  • Voltage Drop: When electricity flows through a cable, there is a natural voltage drop due to the cable’s resistance. Excessive voltage drop can lead to inefficiency and reduced pump performance.
  • Selecting the Right Gauge: Choose a cable gauge (thickness) that minimizes voltage drop. Thicker cables have lower resistance and result in less voltage loss.

Cable Length:

  • Longer Cables: Longer cable runs between the solar panels, controller, and pump increase resistance and voltage drop.
  • Calculate Total Length: Measure the total distance from the solar array to the pump location. Include both vertical and horizontal distances.
  • Choose Adequate Cable Length: Select cables that comfortably cover the entire distance without a voltage drop, as this affects the operation of the pump..

Environmental Factors:

  • UV Resistance: Solar cables are exposed to sunlight. Ensure they are UV-resistant to prevent degradation over time.
  • Temperature Tolerance: Consider the local climate. Cables should withstand extreme temperatures.
  • Outdoor Durability: Solar cables are typically installed outdoors. They must withstand weather conditions, moisture, and physical wear.

3. Brushless DC Motors and Their Relevance to Solar Pumps:

Brushless DC motors represent a technological leap forward in the realm of solar pump efficiency. With their superior efficiency and durability, these motors are ideally suited for solar applications.

Understanding Brushless DC Motors:

  • Unlike traditional brushed motors, BLDC motors operate without physical brushes.
  • Key Components:
    • Stator: Fixed part with windings.
    • Rotor: Rotating part with permanent magnets.
    • Electronic Controller: Manages the motor’s operation.

Superior Efficiency:

  • BLDC motors exhibit high efficiency due to reduced energy losses from brush friction.
  • They convert electrical energy into mechanical power with minimal waste.
  • Efficiency directly impacts the overall effectiveness of solar-powered systems.

Durability and Reliability:

  • Brushless motors have fewer moving parts, leading to increased durability.
  • Reduced wear means a longer lifespan and less maintenance.
  • Ideal for remote or hard-to-access locations where maintenance is challenging.

Solar Pump Applications:

  • BLDC motors are tailored for solar pumps:
    • Low Voltage Operation: BLDC motors can operate successfully at low voltages, aligning with solar panel output.
    • Stable Performance: Consistent torque and speed even under varying solar conditions.

Maximizing Energy Harvest:

  • BLDC motors optimize energy utilization by adjusting speed and torque based on available sunlight.
  • They adapt to changing solar intensity, ensuring efficient water pumping.
  • Harvested energy is maximized, contributing to overall system effectiveness.

Reducing Maintenance Costs:

  • Longer motor life means fewer replacements and associated costs.
  • Minimal wear translates to reduced downtime and maintenance efforts.
  • BLDC motors contribute to sustainable and cost-effective solar water pumping.

4. Advantage of Maximum Power Point Tracking (MPPT):

Maximum Power Point Tracking (MPPT) technology is a game-changer for solar pump systems, allowing for precise control and optimization of energy output. By constantly adjusting the operating point of the solar panels, MPPT maximizes energy harvest, even in varying sunlight conditions.

What Is MPPT?:

  • MPPT stands for Maximum Power Point Tracking.
  • It’s an essential technology used in solar photovoltaic (PV) systems.
  • The primary goal of MPPT is to continuously optimize the maximum power point (MPP) of solar panels.

How Does MPPT Work?:

  • Precise Control: MPPT adjusts the operating point of solar panels to extract the highest amount of power from sunlight.
  • Dynamic Adaptation: It adapts to varying sunlight conditions, ensuring optimal energy harvest.
  • Efficiency Boost: By tracking the MPP, MPPT maximizes the conversion of solar energy into usable electrical power.
  • Reduced Maintenance Costs:
    • Operating pumps near optimum input power minimizes electrical losses.
    • This extends the lifespan of components and reduces maintenance needs.

Reliability and Sustainability:

  • MPPT contributes to the reliability of solar pump systems.
  • By maximizing energy harvest, MPPT promotes sustainable water management practices.

5. Converting Current Pumps to Solar:

For those looking to transition to solar power, converting existing electrical pumps presents a viable option. In this section, we’ll outline the steps involved in converting conventional pumps to solar power, from assessing power requirements to selecting compatible components. By making the switch to solar, you can enjoy sustainable water pumping solutions while minimizing environmental impact and operational costs.

Assess Power Requirements:

  • Begin by calculating the power consumption of your current electric pump. This step helps determine the size and number of solar panels needed for the conversion.
  • Consider factors such as the pump’s kilowatt(kW), age, Voltage and if the pump is single or three phase.
  • Older pumps may require additional solar panels to offset their less efficient power usage.

Select a solution tailored for you:

  • The first option is to use your pump and motor as is and install an appropriate inverter to supply power to your pump motor.
  • The second option is to replace your current motor with a brushless DC motor.

Consider Pump Specifications:

  • Kilowatt: Higher kW pumps require more solar panels and a larger inverter. An inverter converts incoming DC voltage to AC voltage, allowing the pump to run on solar power.
  • Age of the Pump: Older pumps tend to consume more power. Adjust the system size accordingly.

6. Grid-Tied vs. Not-Grid-Tied:

The choice between grid-tied and off-grid solar pump systems hinges on various factors, including location, power requirements, and budget considerations. We’ll compare and contrast these two options, highlighting the advantages and considerations for each. Whether you seek independence from the grid or seamless integration with existing infrastructure, understanding the nuances of grid-tied and off-grid systems is essential for informed decision-making.

1. Grid-Tied Solar Pump Systems:

  • Overview: Grid-tied systems are connected directly to the utility power grid and to solar panels. Here’s how they work:
    • Solar panels generate electricity from sunlight.
    • The energy produced is sent to the pump.
    • When there is not enough sunlight, the Inverter then draws from the Utility power source to compensate for the lack of sunlight.
  • Advantages:
    • Cost-Effective: Grid-tied systems can be more costly, as the equipment required needs to be able to handle both DC and AC power sources.
    • Utility Interaction: Seamless integration with the existing grid infrastructure.
    • Your pump will run even during night time.

2. Off-Grid Solar Pump Systems:

  • Overview: Off-grid systems operate independently of the utility grid:
    • Solar panels generate electricity.
    • This is then supplied directly to your pump.
    • No connection to the grid; ideal for remote locations.
  •  Advantages:
    • Energy Independence: You’re not reliant on the grid.
    • Remote Applications: Perfect for areas without grid access.
    • Cost: Off-grid systems tend to be more cost-effective.
  •  Cost Estimate:
    • Off-grid systems vary widely in cost due to the different panel sizes available in the market.

3. Factors to Consider when Making Decisions:

  • Grid Availability: Take into account the availability of grid connections. In remote areas, off-grid solutions may be the sole option.
  • Financial Considerations: Assess the initial costs and potential long-term savings.
  • Dependability: Evaluate the importance of having a continuous water supply for your specific needs.
  • Environmental Impact: Take into consideration the impact on the environment and your ecological footprint.

Environmental Considerations:

  • Solar Irradiance: The quantity of sunlight impacts pump flow rate, with higher irradiance resulting in increased water pumping during daylight hours.
  • Panel Temperature: The efficiency of panels decreases as temperature rises, with efficiency dropping by approximately 0.48% for every 1°C increase.
  • Seasonal Variations: Solar panel efficiency fluctuates throughout the year, necessitating an understanding of these variations to optimize system design.

Harnessing the inexhaustible power of the sun, these systems not only offer a reliable means of powering essential operations but also significantly contribute to reducing carbon footprints and mitigating environmental impact. By delving into the intricacies of the components and considerations highlighted in this guide, you’re equipped to optimize the efficiency, reliability, and lifespan of your solar pump system. This proactive approach not only ensures the seamless functioning of your operations but also positions you at the forefront of environmentally responsible practices. Embracing solar pumping technology not only secures a more sustainable future for water resource management but also heralds a broader shift towards a greener and more resilient world.

Unleash the transformative power of solar pumping technology with AxFlow AQS Liquid Transfer. Our innovative solar pumps are engineered to optimize your pumping operations, offering maximum productivity while minimizing downtime. Count on us to be your trusted partner in delivering sustainable and efficient solutions for all your pumping needs. Reach out to AxFlow AQS Liquid Transfer today, and allow us to guide you towards elevating your pumping systems to new levels of performance and environmental responsibility.

Do you still have questions? Give our AQS Liquid Transfer team a call on +27 12 548 7204 or fill out our enquiry form, our friendly team will get back to you with first-hand expertise on how to select a borehole pump for your needs.

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