Complete Solar-Powered Water System: Borehole, Pump, Storage & Irrigation

How a Solar-Powered Water System Works

A solar-powered water system uses solar energy to pump water from a borehole or other source into storage, then distributes that water for domestic, livestock, irrigation or commercial use.

A typical system consists of the water source, pump, solar array and controller, storage, treatment, distribution and end-use equipment. The components must be designed together so that the available water, hydraulic requirements and energy supply are balanced.

For many pumping applications, storage replaces the need to store electricity in batteries. Solar power pumps during available daylight hours, while the tank holds water for later use.

1. Assess the Water Source

The system starts with a reliable water source. This may be a borehole, harvested rainwater, surface water, municipal supply or a combination of sources.

For boreholes, design should be based on measured groundwater conditions rather than an assumed yield. WRA requires motorised boreholes to undergo test pumping, with current regulations specifying a continuous constant-rate pumping test of at least 24 hours and a recovery period of at least 20 hours unless otherwise stipulated by the Authority. :contentReference[oaicite:2]{index=2}

WRA also emphasises professional groundwater assessment, borehole siting, construction, supervision and pumping-test procedures to support sustainable abstraction. :contentReference[oaicite:3]{index=3}

2. Calculate Water Demand

List every intended use before selecting equipment: household consumption, livestock, irrigation, cleaning and any commercial or institutional demand.

For irrigation, water requirements should be calculated from local climate, reference evapotranspiration, crop characteristics, growth stage, rainfall and irrigation-system performance. FAO's revised 2025 guidance continues this approach using updated evapotranspiration methods and crop information. :contentReference[oaicite:4]{index=4}

Peak demand is also important. The system must handle periods when several uses occur at the same time, even when average daily demand is much lower.

3. Size the Pump and Solar System

Pump selection is based mainly on two parameters: required flow and total dynamic head. Total dynamic head includes the pumping water level, elevation difference, pressure requirements and friction losses in the pipework.

The pump duty must remain within the sustainable yield of the water source. Once the pump duty is established, the solar array and controller are selected to provide the required energy under the site's expected solar conditions.

This is why purchasing a pump first and attempting to fit the rest of the system around it is poor practice. The correct sequence is source assessment, demand calculation, hydraulic design and then equipment selection.

4. Design Storage and Treatment

Storage allows pumping and water use to occur at different times. This is particularly valuable for solar systems because water can be pumped during daylight and used later without relying on electrical battery storage.

Tank capacity should be based on demand, pumping hours, source reliability and the required reserve. Critical applications may require greater resilience or a secondary source such as rainwater, grid power or a generator.

Water treatment should be based on a water-quality test and the intended use. Domestic water may require filtration and disinfection, while irrigation water may primarily require filtration to protect emitters and other equipment. Different uses can therefore require separate treatment lines.

5. Distribute Water and Irrigate

Water can be distributed from storage by gravity or through a booster pump. Elevated tanks can provide useful pressure, while ground-level storage normally requires pumping where pressure is needed.

For irrigation, the mainline, valves, filters, laterals or sprinklers and control zones should be designed around the required flow and operating pressure. The National Irrigation Authority publishes guidance covering irrigation survey, design, implementation and operation. :contentReference[oaicite:5]{index=5}

Where rainwater, borehole water and storage are combined, controls can prioritise available sources and maintain supply without requiring every source to operate continuously.

Reliability, Maintenance and Compliance

A reliable system includes appropriate pump protection, tank-level controls, isolation valves, overflow arrangements and protection against electrical faults and surges.

Routine maintenance should cover solar modules, pumps, filters, tanks, valves, treatment equipment and irrigation components. Maintenance intervals should follow equipment manufacturers' requirements and actual site conditions.

Borehole development and water abstraction should be undertaken in accordance with applicable WRA requirements and authorisations. Solar and electrical works should likewise be carried out under the applicable EPRA and electrical requirements. EPRA currently publishes renewable-energy licensing guidance and solar-PV works documentation. :contentReference[oaicite:6]{index=6}

The objective is not simply to install solar panels and a pump. A properly engineered system should provide adequate water, operate within the source capacity, use energy efficiently, protect water quality and remain serviceable over its operating life.