An off-grid water supply system using a borehole can provide a reliable source of water for homes, farms, schools, businesses and remote properties. The system can operate without depending on the electricity grid by combining a borehole, solar-powered pump, water storage tank and gravity-fed distribution system.
This type of setup is useful in areas where grid electricity is unreliable or unavailable. It can also reduce the recurring energy costs associated with pumping groundwater.
A successful system requires proper planning. The borehole must have enough water, the pump must match the borehole yield, and the storage capacity must meet the expected demand.
What Is an Off-Grid Borehole Water System?
An off-grid borehole water system is a water supply arrangement that operates independently of the public electricity network and, in many cases, the municipal water supply.
The basic system normally includes:
| Component | Main Function |
|---|---|
| Borehole | Provides access to groundwater |
| Submersible pump | Pumps groundwater to the surface |
| Solar panels | Provide electricity for the pump |
| Solar controller | Controls and optimizes pump operation |
| Water storage tank | Stores pumped water |
| Tank stand or tower | Creates pressure for gravity distribution |
| Pipes | Transport water around the property |
| Water treatment equipment | Improves water quality where necessary |
| Flow meter | Measures water abstraction |
The major advantage is that water can be pumped during daylight and stored for use throughout the day and night.
1. Start With a Hydrogeological Survey
The first step is determining whether groundwater is available at the property.
A hydrogeological survey helps identify suitable drilling locations and provides information about the area’s groundwater conditions. It can help guide decisions about the expected drilling depth and groundwater potential.
Do not choose a drilling location simply because a nearby property has a borehole. Groundwater conditions can vary significantly between locations.
In Kenya, groundwater development is regulated. The Water Resources Regulations, 2025 provide requirements covering groundwater development, test pumping, supervision and borehole completion records.
Raeli Hydro can help property owners plan the project from the survey stage through drilling and system installation.
2. Obtain the Required Approvals
Before drilling, ensure that the necessary water-resource approvals and permits are obtained.
A professional borehole project should comply with the requirements of the Water Resources Authority (WRA) and other applicable authorities.
The regulations also require professional supervision for boreholes that will be equipped with motorized pumps. After construction, a borehole completion record and completion certificate must be submitted within the required period.
This step should not be skipped.
Proper approvals help protect groundwater resources and reduce the risk of problems during or after construction.
3. Drill and Construct the Borehole
Once the site has been approved, the drilling process can begin.
The drilling contractor creates the borehole to the required depth. The borehole is then fitted with appropriate casing and screens based on the geological conditions encountered.
The construction process should be carefully documented.
The final borehole depth, geological formations, water strikes and construction details are important when selecting the pumping equipment.
A properly constructed borehole should also be protected against contamination from surface activities.
4. Carry Out a Pumping Test
A borehole may contain water but still be unsuitable for a particular demand.
This is why borehole yield testing is important.
The pumping test determines how much water the borehole can sustainably provide. It also provides information that helps engineers select an appropriate pump.
Under Kenya’s current regulations, boreholes and wells that will be equipped with motorized pumps are subject to test pumping. The prescribed test includes a continuous constant-rate pumping period of at least 24 hours and a recovery period of at least 20 hours, unless otherwise stipulated by the Authority.
The pump should never be selected simply because it is powerful.
An oversized pump can cause excessive drawdown and may lead to inefficient operation or damage to the borehole.
5. Select a Solar-Powered Borehole Pump
The next major component is the solar borehole pump.
For most off-grid systems, a submersible pump is installed inside the borehole. Solar panels provide the electricity needed to operate the pump.
The pump should be selected based on several factors:
- Borehole yield
- Borehole depth
- Static water level
- Dynamic water level
- Required daily water volume
- Vertical lifting height
- Pipe length and diameter
- Required flow rate
- Solar availability
A professional design prevents the common mistake of installing a pump that is either too small or too large.
Raeli Hydro provides solar-powered borehole pumping solutions that can operate independently of the electricity grid.
6. Install Solar Panels
The solar photovoltaic panels provide energy for the borehole pump.
The number and capacity of panels depend on the pump’s electrical requirements and the expected daily water demand.
An important feature of an off-grid water system is that you do not necessarily need batteries.
Instead, the system can use a water tank as its energy storage mechanism.
During sunny hours, solar panels power the pump. The pump fills the elevated or ground-level storage tank. Water can then be used later when there is little or no sunlight.
This approach can be simpler than using large battery banks.
7. Install Adequate Water Storage
Water storage is one of the most important parts of an off-grid system.
The storage tank should be large enough to provide water during periods when the pump cannot operate.
For example, if the property uses water throughout the evening and early morning, the tank should hold enough water to cover this demand.
Storage requirements depend on the number of users and the purpose of the water supply.
A household may require a relatively modest tank, while a farm, school, guesthouse or commercial property may require several tanks or a much larger storage system.
8. Use Gravity Where Possible
One of the simplest ways to reduce energy requirements is to place the storage tank at an appropriate elevation.
A tank installed on a water tower can use gravity to distribute water to taps, bathrooms, livestock areas and irrigation points.
This means the solar pump does the hard work of lifting water from the borehole to the tank. Gravity then moves the water through the distribution network.
Where sufficient elevation is not available, a pressure pump can be installed.
9. Add Water Treatment
Borehole water should not automatically be assumed to be safe for drinking.
Groundwater can contain naturally occurring minerals and other contaminants. Water quality can also vary between locations.
A borehole water quality test should therefore be carried out before the water is used for drinking or food preparation.
Depending on the laboratory results, treatment may include:
- Sediment filtration
- Activated carbon filtration
- Iron removal
- Water softening
- Fluoride treatment
- Ultraviolet disinfection
- Chlorination
- Reverse osmosis
Kenya’s regulations allow the Authority to require water-quality analysis, and where results show that water is not suitable for human consumption, appropriate treatment may be required before it is used for that purpose.
10. Install a Reliable Distribution Network
The final stage is connecting the storage system to the property.
The distribution network can supply:
- Household taps
- Showers
- Toilets
- Kitchens
- Laundry areas
- Livestock watering points
- Greenhouses
- Irrigation systems
- Commercial facilities
Pipe sizes should be selected according to the expected flow and distance.
A well-designed system also includes valves that allow individual sections to be isolated during maintenance.
Why Choose an Off-Grid Borehole System?
An off-grid borehole water supply provides several benefits.
Reduced Dependence on Grid Electricity
Solar pumping allows groundwater to be extracted without depending on the public electricity network.
Lower Running Costs
Once installed, solar energy has no conventional fuel cost. Maintenance is still required, but regular electricity consumption can be reduced.
Reliable Water Storage
A large storage tank provides a reserve that can be used when the sun is unavailable.
Useful for Remote Properties
Off-grid systems are particularly useful for farms, rural homes, lodges, schools and other properties located far from electricity infrastructure.
Expandable Design
The system can be expanded by increasing storage capacity, adding solar panels or upgrading distribution infrastructure when demand increases.
Maintenance Is Essential
An off-grid system still requires regular maintenance.
Solar panels should be kept clean. Pump performance should be monitored. Tanks should be inspected and cleaned. Pipes, valves and fittings should be checked for leaks.
The borehole’s water level and abstraction should also be monitored.
Kenya’s current groundwater regulations require borehole abstractors to use water meters and provide for monitoring of groundwater data.
Regular water testing is also recommended where groundwater is used for drinking.
Build Your Off-Grid Water System With Raeli Hydro
A successful off-grid borehole water supply system is more than a drilled hole and a solar pump. It is an integrated system in which the borehole, pump, solar array, storage tank, treatment equipment and distribution network work together.
Raeli Hydro provides borehole drilling, pumping, solar borehole systems, water testing and related groundwater solutions in Kenya. Its services include borehole siting, drilling, pump installation, yield testing and solar-powered pumping systems.
For a new project, the best approach is to start with a professional groundwater assessment, determine the expected water demand, drill and test the borehole, and then design the solar pumping and storage system around the actual borehole performance.
This approach creates a more reliable and efficient off-grid water supply system using a borehole that can serve the property for many years with proper operation and maintenance.