Solar Powered Bore Pumps
The most common type of solar pump is the submersible bore pump. These pumps are used in bore holes or wells with a depth of up to 250 metres! The cost of a solar bore pump system is directly proportional to the required litres per day and the vertical lift (also known as head).
A low vertical lift combined with a moderate water flow rate requires a lot less power, or in other words, less solar panels. If your water pipes are long, narrow, and/or the flow rate is high, pipe friction will also need to be considered.
Below are three typical solar bore pump systems designed for Northern NSW. Many other configurations are possible (and available). The selection of the most appropriate pump should be based on the actual requirements (location, volume and pressure/head). Solar pump systems are supplied as DIY install kits only.
| litres/day @ vertical lift | Solar Pump System | Price | ||
|---|---|---|---|---|
| 7,600 @ 10 m | or | 2,000 @ 40 m | Grunfos SQFlex 1-8N with 0.36kW PV | from $2980 |
| 17,000 @ 5 m | or | 11,000 @ 15 m | Lorentz PS150 with 0.4kW PV | from $3490 |
| 5,200 @ 70 m | or | 4,800 @ 120 m | Grundfos SQFlex 1.2-2N with 0.7kW PV | from $5290 |
High Value - Grundfos SQFlex 1-8N
Grundfos SQFlex centrifugal rotor pumps are solar or mains powered submersible pumps are rugged pumps for use in 3" or larger well casings. Ideal for remote homes and cabins, irrigation or livestock watering. Works from a single high voltage 360W solar modules without a Pump Controller. Other SQFlex pumps for higher lifts or flow also available.
The below system configuration will pump water up to 40m, delivering about 500 litres per hour (@ full sunshine) or 1,900 litres at 10m lift.
High Value Grundfos solar pump system
- 1 x 400W Sunpower Maxwon3® solar panel
- 1 x Grundfos SQFlex 1-8N submersible pump
- 2 m solar cable and MC4 connectors
- 12 m underwater bore cable
- DC Breaker (IP66)
- Potting of bore cable
- Installation & operation manuals
Price: from $2980
High Flow - Lorentz PS150 C-SJ5-8
Lorentz PS150 centrifugal rotor pumps are submersible pumps made of type AISI 304 stainless steel with 96mm diameter. Centrifugal rotors are typically used for low to medium heads and high flows.
The below system configuration will pump water up to 20m, delivering about 1,600 litres per hour (@ full sunshine) or 9,000L/day.
Lorentz PS150 solar pump system (ø 96mm)
- 2 x 210W 24V Trina Quadmax solar panel
- 1 x Lorentz PU150 C-SJ5-8 submersible pump
- 1 x Lorentz PS150 Pump Controller
- 1 x Lorentz Well Probe Sensor & cable
- 2 m solar cable and MC4 connectors
- 12 m underwater bore cable
- DC Breaker (IP66)
- Potting of bore cable
- Installation & operation manuals
Price: from $3490
High Lift - Grundfos SQFlex 1.2-2N
Grundfos SQFlex helical rotor pumps are skinny (ø 74mm) submersible pumps suitable for narrow bore holes. Helical rotors are typically used for medium to high heads and low to medium flows. The SQFlex is made of type AISI 316 stainless steel for slightly aggressive water.
The below system configuration will pump water up to 120m, delivering about 1200 litres per hour (@ full sunshine) or 1,300 litres at 70m lift.
Grundfos SQFlex solar pump system (ø 74mm)
- 2 x 370W Trina Honey Black® solar panel
- 1 x Grundfos SQFlex 1.2-2N submersible pump
- 2 m solar cable and MC4 connectors
- 12 m underwater bore cable
- DC Breaker (IP66)
- Potting of bore cable
- Installation & operation manuals
Price: from $5290
Lorentz
The Lorentz pump relies on a pump controller and included water sensor(s) to optimise its performance. The controllers allow for integration of batteries where required. The Lorentz uses a centrifugal rotor which are maintenance free.
Other features include:
- For potable water wells
- Fits in 3" or larger well casing
- Stainless steel housing
- Dry running protection (with level sensor)
- Easy to service.
Grundfos
The commercial grade Grundfos SQFlex pump range is both powerful and feature rich. Integration of a generator is possible with help of the IO 101 controller. Other features include:
- Dry running protection with auto-restart
- Stainless steel pump casing for long service life
- Carbon Ceramic bearings ensure high reliability
- High efficiency MSF3 motor with permanent magnets
- Over and under voltage protection
- Overload protection
- Over temperature protection
- Maximum power point tracking (MPPT)
- 30 - 300 V DC or 90 - 240V AC input
Solar Pump System vs Diesel Pump
The supporting arguments for a solar pump system are compelling and proven in numerous independent studies and reports. While upfront cost of a solar pump system is higher compared to Diesel systems, the operational cost (fuel, parts, time spent on maintenance) is considerably lower. A comprehensive feasibility assessment back in 2006 (when solar was still expensive) estimated payback in as little as 2 years. NSW Farmers once published a report [link now defunct] that even takes additional water tanks into account, and still, Solar Pumps win by a long shot.
Applications
Apart from bore holes and wells, submersible pumps can also be used in dams. Floating device are available to prevent the pump from sinking to the ground (and in the mud). Submersible pumps are also frequently used in water storage tanks for water transfer applications (e.g. to pump to a header tank). In this case you may simply 'hang' the pump from the ceiling of the tank.
Installation
Solar bore pump systems are simple to install. The only tricky bit is the waterproof connection between the pump and the underwater DC cable (Potting of Cable). In fact, if done incorrectly, it renders warranty invalid. The above system prices include potting by RPC.
Watch the SQFlex Installation Video which explains the process step by step. Please also view a customer submitted installation example or read more information on SQFlex Pump Systems and components.
You could also employ an Off-Grid accredited installer and claim STCs. For example, the 2 Panel Grundfos Kit would currently create $306 worth of STCs. You may also qualify for other rebates.
Should you ever get stuck during installation or thereafter, phone and/or email support is available at no extra cost. Note: Rainbow Power Company does not install pump systems.