Solar-Powered Water Pumping — Zero Fuel, Maximum Reliability
A solar water pump replaces the diesel engine or KPLC pump motor with a solar panel array and an efficient DC or variable-speed AC motor — delivering water when the sun shines, with zero fuel cost. In areas where diesel fuel logistics are expensive or grid power is unreliable, solar pumping reduces the total cost of water delivery by 60–90% compared to diesel systems.
As Kenya's premier borehole drilling and water management company, Vajra Drill has a distinct advantage in solar pump projects: we drill the borehole, design and install the solar pump system, and provide ongoing maintenance — all from one team. This integrated capability means every solar pump is correctly matched to the proven borehole yield and static water level, eliminating the most common cause of pump failure: incorrect sizing.
We supply and install Lorentz solar pump systems (Germany's leading solar pump brand), Grundfos SQFlex, Shimge Solar, and Davis & Shirtliff solar pump solutions — matching the right technology to each application based on flow requirements, pumping head, and solar resource.
Solar Pump System Types
DC Submersible Solar Borehole Pumps
The most efficient solar pump design — DC brushless motors (Lorentz, Grundfos SQFlex) run directly from solar panels with no AC inverter losses. Suitable for boreholes from 15m to 300m+ depth. The pump runs at variable speed proportional to solar irradiance, automatically pumping faster in full sun and slowing in cloud — perfectly matched to a storage tank that buffers demand. Minimal moving parts means very low maintenance.
AC Solar Pump Systems with VFD
Variable-frequency drive (VFD) systems convert solar DC power to variable-frequency AC, driving standard AC submersible or surface pump motors. VFD solar pumping is ideal where existing AC pump infrastructure is to be retained, or where higher-power pumps (above 7.5kW) make DC pump options less economic. The VFD provides soft-start, variable speed, and pump protection functions.
Surface Solar Pump Systems
For pumping from rivers, dams, ponds, and shallow wells where the water source is near surface level. Solar surface pump sets are mounted above water level, feeding irrigation systems or storage tanks. Suitable for flows from 1 m³/hour to 200+ m³/hour depending on solar array size. Widely used for irrigation abstraction from rivers and small dams in Kenya's agricultural areas.
Floating Solar Pump Systems
Solar panels mounted on floating platforms directly on dams and reservoirs — panels float on the water surface, powering submersible pumps below. Floating solar has the added benefit of reducing evaporation from open water bodies. Popular for large irrigation reservoirs, fish farms, and water supply schemes in semi-arid Kenya where water conservation is critical.
Solar Pump Controllers & Monitoring
Lorentz PSk2 and PSk3 controllers provide dry-run protection, level sensing, float-switch integration, and GSM telemetry for remote monitoring and control. We install tank level sensors that automatically stop the pump when the storage tank is full and restart when it drops — fully automatic and unattended operation ideal for remote water supply schemes.
How We Design & Install Your Solar Pump System
Correct solar pump selection requires detailed engineering — wrong sizing wastes money or leaves you with insufficient water. Here is our process.
- 1Borehole & Water Source Data Collection
We collect borehole completion report data (static water level, pumping water level, casing diameter, tested yield) or assess surface water source characteristics — the foundation of accurate system design.
- 2Hydraulic Pump Sizing
We calculate the required flow rate and total dynamic head (TDH), then select a pump operating at its Best Efficiency Point (BEP). Lorentz Pumps Designer or equivalent software is used to match pump to solar array output.
- 3Solar Array Design
Panel quantity, string configuration, and mounting tilt are designed to match pump power requirements throughout the day. We account for seasonal irradiance variation to ensure adequate daily pumping hours year-round.
- 4Panel Mounting & DC Wiring
Panels are mounted on galvanised structures at the optimal tilt angle for the site latitude. UV-rated DC cable runs to the controller or VFD, protected in conduit throughout.
- 5Pump Lowering & Rising Main Installation
The pump is lowered on stainless-steel safety rope, HDPE rising main is connected in sections, and the borehole head assembly is sealed. Drop cable is tied to the rising main at regular intervals to prevent pulling stress.
- 6Controller Setup, Testing & Handover
MPPT controller or VFD is configured for dry-run protection, float-switch integration, and GSM telemetry. System is tested over a full solar day to verify pump output versus design. Operating manual and maintenance schedule are issued.
Solar Pump Applications in Kenya
Homesteads & Farms
Reliable water supply for rural homes, farmsteads, and livestock without fuel dependency
Smallholder Irrigation
Solar pumps from rivers or boreholes powering drip or furrow irrigation for food crops
Schools & Institutions
Sustainable borehole pump systems for schools, health centres, and community facilities
Water Kiosks
Solar pump + storage + kiosk dispensing for village water supply schemes in rural Kenya
Commercial Horticulture
High-flow solar pump arrays for large flower farms, processing plants and agri-businesses
Livestock Watering
Solar-powered cattle troughs, dip tanks, and pastoral community water points
Frequently Asked Questions
Solar pumps are sized to pump sufficient water during daylight hours to fill storage tanks for 24-hour demand. The tanks (typically elevated or pressurised) supply water at night without pumping. On heavily overcast days, the pump runs slower but still pumps. Well-designed systems include 2–3 days of storage reserve. For critical applications, a battery-backup or small generator can be added.
Lorentz and Grundfos SQFlex DC solar pumps can handle total dynamic heads (TDH) of up to 300+ metres, covering virtually all Kenyan borehole depths. The solar pump system is sized specifically to your borehole's measured static level, pumping test dynamic level, required flow rate, and pump-to-tank elevation. Correct sizing is critical — Vajra Drill's advantage is that we test every borehole before sizing the pump.
For most rural and off-grid applications in Kenya, yes. Diesel pumps cost KES 40–80 per m³ of water delivered (fuel + maintenance). Solar pumps deliver water for KES 2–5 per m³ (amortised capital cost only, no fuel). The break-even compared to diesel is typically 18–30 months, after which pumping is essentially free. KPLC-powered borehole pumps are cheaper to run than diesel but are vulnerable to outages, tariff hikes, and power-quality issues that damage motors.