Solar Powered Irrigation and Farm Energy Solution in Northern Kenya
Project Background
Mr. Hassan operates a 6-hectare commercial farm primarily growing tomatoes and onions. The farm is located in an arid and semi-arid region of northern Kenya, where dry-season irrigation is a critical challenge for agricultural production.
Irrigation Challenges
During the dry season, irrigation is essential to sustain crop growth. Previously, Mr. Hassan relied on a diesel-powered water pump. However, the pump suffered from frequent breakdowns and poor reliability. In addition, the operating cost was extremely high, with annual diesel expenses exceeding 300,000 Kenyan shillings.
Frequent maintenance tasks such as oil changes, filter replacements, and repairs not only increased costs but also consumed valuable time during peak farming seasons.
The farm requires a large and stable water supply with a flow rate of 20–25 cubic meters per hour, operating approximately 6 hours per day. Mr. Hassan needed a high-flow, low-head solar pumping solution capable of extracting water from a shallow well without relying on expensive diesel fuel.
System Design Solution
Mr. Hassan selected a 2.3 HP Flowatts solar water pump as the core irrigation solution. The pump is powered directly by a dedicated photovoltaic (PV) array through its built-in MPPT controller, ensuring high efficiency and a simple system structure.
To extend irrigation beyond peak sunlight hours, a PowMr inverter and battery energy storage system was added. This allows irrigation and farm operations to continue during early mornings, evenings, and periods of insufficient sunlight.
The Flowatts pump has a rated power of 2.2 kW, a maximum flow rate of 32 m³/h, and a maximum head of 25 meters. Under actual operating conditions on the farm, the working head is 10–12 meters, delivering a stable flow of 20–25 m³/h, fully meeting irrigation needs.
Dual Subsystem Architecture
Flowatts Solar Pump Subsystem
- Dedicated solar PV array directly connected to the Flowatts pump
- Operates through the pump’s built-in MPPT controller
- Simple structure with high efficiency and reliability
- Provides stable irrigation during periods of strong sunlight
PowMr Farm Power Subsystem
- Independent PV array connected to a PowMr hybrid inverter
- Supplies power to farm equipment during the day
- Charges batteries simultaneously for energy storage
- Delivers power at night or during low solar radiation
The two subsystems operate independently without interference, ensuring both reliable irrigation and uninterrupted farm electricity supply.
PowMr Solar Power System Configuration
The PowMr solar power system is equipped with an independent PV array consisting of 16 × 300 W solar panels. The array connects to a PowMr 6.2kW all-in-one inverter with dual MPPT trackers to maximize energy harvest from differently oriented PV strings.
| Parameter | Specification |
|---|---|
| Rated Power | 6200W |
| DC Input Voltage | 48 VDC |
| AC Output | 220 V AC (Pure Sine Wave) |
| PV Input Power | 8500W |
| MPPT Trackers | Dual MPPT |
| Maximum Charging Current | 120A |
| Parallel Capability | Up to 9 units |
The 6.2 kW inverter was chosen to provide sufficient power margin, easily handling the high startup current of the 2.2 kW water pump. The dual MPPT design improves energy efficiency throughout the day.
Energy Storage System
The system includes two PowMr 200Ah lithium batteries.
| Parameter | Specification |
|---|---|
| Rated Capacity | 200 Ah |
| Nominal Voltage | 51.2 V |
| Total Energy | 10.24 kWh |
| Battery Type | LiFePO₄ |
| Cycle Life | >6000 cycles (80% DOD) |
Considering system efficiency and depth of discharge, the battery system provides approximately 3.5 hours of backup operation, which is especially valuable for irrigation scheduling and nighttime farm operations.
Farm Electrical Loads
- Lighting System: LED lighting for offices, warehouses, and night patrols, with low energy consumption and high efficiency.
- Cold Storage Equipment: A 200-liter solar refrigerator operating continuously with an average daily energy consumption of about 10 kWh, essential for preserving tomatoes and onions.
- Electric Tools: Power tools such as drills, cutters, and grinders with power ratings of 500–800 W, easily supported by the 6.2 kW inverter.
Operational Results
After installation, both the solar pumping system and the farm power system demonstrated excellent reliability. Since each system operates on an independent PV array, irrigation performance is not affected by other farm electricity usage.
- 24/7 Power Supply: Solar energy powers farm equipment during the day while charging batteries, which provide electricity at night or during cloudy conditions.
- Stable Water Output: The pump consistently delivers 20–25 m³/h at a working head of 10–12 meters, sufficient to irrigate up to 4 hectares per day using drip irrigation.
- Scalable System Design: The PowMr inverter supports parallel operation of up to nine units, allowing easy future expansion.
Conclusion
This project successfully replaced a costly and unreliable diesel irrigation system with a clean, efficient, and scalable solar solution. By combining a dedicated solar pumping system with an independent farm power and energy storage system, Mr. Hassan achieved reliable irrigation, significant cost savings, and round-the-clock electricity supply, supporting sustainable agricultural development in northern Kenya.