Pumping systems
In the area of transporting water and waste water there are a huge number of options. However, especially in a decentralised environment reliable, energy autonomous and cost effective water pumps are extremely important.
That's why some companies have developed pumps that can be driven by solar power as well as manually.
A large range of solar powered pumps are currently available: From very small ones - as the one below - to quite large solar pumping systems. One of the largest solar pumps currently available delivers about 160m³ day with a lift (meters head) of around 8 meters. The costs for the pump is well below ? 1,000. However, the solar power required for that kind of system is around 1,800 Wp. This shows that the bottleneck on price is not the pump but rather the energy supply. To improve the cost efficiency of solar powered pumping system is to use
- solar tracking devices (manual or automatic)
- water storage tanks to save on electrical components and battery
Direct Solar well pump - Smaller system
A small solar well pump has many useful applications for family or for smaller farms
- Stock watering
- Drip irrigation
- Water supply for cabins and remote houses
- Any place where water is needed but no AC power is available
The more sunlight, the more water is pumped (this is ideal for stock watering and irrigation). Water is pumped even on hazy days.
- automatic operation for years
- minimal maintenance
- allows dry operation (for a few hours)
- tolerates mild sediments (ideally clear water)
- diameter of borehole required of 8 cm
- robust and reliable (constructed from brass and stainless steel)
- up to 30m deep wells
- Type: LJ20-D with 2 crystalline solar panels of 12 Wp each
DC Battery powered pumps - Smaller to medium size systems
According to the individual needs there are plenty of different pump models available powered by 12 or 24 VDC.
Example:
Technical Specifications DWC FLS1024
Pump design: Positive Displacement 3 Chamber Diaphragm pump
CAM: 3.0 Degree
Motor: Permanent Magnet, PIN 11 126-10 (Thermally protected)
Voltage: 24VDC Nominal
AMPS: 4.0 Max
Internal Bypass: 105 - 110 PSI / 7.2 Bar
Max Lift: 230 Ft / 70m
Maximum Submersion: 230 Ft / 70m
Outlet port: 1/2" (12,7mm) barbed fitting for 1/2" (12,7mm) I.D. Tubing
Inlet: 50 Mesh Stainless Steel screen
Materials: High Strength Engineered Plastcis, Stainless steel fasterners
Typical Applications: Potable Water Well pump
Net Weight: 6 LBS
List of DC pumps available
Solar well pump - medium to large size systems
| Solar power (Wp) | Voltage (V) | Lift height (m) | Max Flow rate (m³/h) |
| 100-300 | 24-48 | 0-50 | 0.8 |
| 100-300 | 24-48 | 0-30 | 1.2 |
| 100-300 | 24-48 | 0-20 | 2.7 |
| 300-500 | 48-72 | 0-140 | 0.5 |
| 400-900 | 48-72 | 140-180 | 0.5 |
| 300-500 | 48-72 | 0-80 | 0.8 |
| 400-900 | 48-72 | 80-140 | 0.8 |
| 400-900 | 48-72 | 40-90 | 1.2 |
| 400-900 | 48-72 | 30-60 | 1.9 |
| 300-900 | 48-72 | 0-50 | 2.7 |
| 400-900 | 48-72 | 0-30 | 3.6 |
| 350-500 | 72-96 | 0-140 | 0.5 |
| 400-900 | 72-96 | 140-240 | 0.5 |
| 350-400 | 72-96 | 0-80 | 0.8 |
| 400-1200 | 72-96 | 80-160 | 0.8 |
| 400-1200 | 72-96 | 40-120 | 1.2 |
| 400-1200 | 72-96 | 30-80 | 1.9 |
| 350-1200 | 72-96 | 0-60 | 2.7 |
| 500-1200 | 72-96 | 0-40 | 3.6 |
| 100-450 | 12-24 | 2-22 | 5.0 |
| 300-900 | 48-72 | 0-25 | 7.5 |
| 300-900 | 48-72 | 0-18 | 11 |
| 350-1200 | 72-96 | 0-40 | 7.5 |
| 350-1200 | 72-96 | 0-24 | 11 |
| 350-1200 | 72-96 | 0-15 | 21 |
| 350-1200 | 72-96 | 30-60 | 6 |
| 300-1800 | 72-96 | 2-40 | 11 |
| 300-1800 | 72-96 | 2-25 | 16 |
| 300-1800 | 72-96 | 2-12 | 22 |
Booster pumps for solar operation - provides city water pressure
It has been a standard in home renewable energy systems since 1986. It is economical for domestic water supply, drip irrigation and water purification. Use solar-electric power to provide 250 to 10,000ltrs per day from shallow water sources.
Solar powered booster pumps can push water as high as 140m (460ft). For 12 to 24V systems (1-2 solar modules or batteries in series) uses only one and the same motor and controller for solar direct or battery systems. Same flow at 12V or 24V ! The solar powered booster pump is not submersible, but can draw water from shallow wells, springs, cisterns, tanks, ponds, rivers and streams and push it through miles of pipeline. Applications can be drinking water supply, water purification and filtration, pressurising for home water systems, drip irrigation or water circulation in thermal solar collectors (max. +60 oC, +90 oC on request).
Slow pumping minimizes the size and cost of the solar array-battery system, wire and piping. The solar powered booster pump is more powerful, quieter and much more durable than plastic RV/Marine pumps. It is less expensive than submersible DC pumps.
Wearing parts typically last 5 to 10 years. Overall life expectancy is 15 to 20 years.
Suction Capacity is 5 vertical meter (20ft) at sea level. Subtract 1m for every 1000m altitude. Pump should be placed as low and as close as possible to the water source. Suction capacity my be further limited by intake pipe friction (or clogged filter) Intake piping should be 1? or larger.
Filtration Requirement: This kind of pump CANNOT tolerate dirt. Water MUST be filtered clear. If water is very dirty, improve the source or consider a different pump.
Battery operation is highly recommended.
Performance ranges from 5m - 140m (Total lift), 222l/h - 900l/h with power consumption from 35 Watt to 225 Watt.
Checklist for correct pumping layout
In order to select the best possible pump with the supporting PV or other renewable energy power supply the following questions need to be answered:
Well
- total vertical lift
- depth of well
- recovery rate
- length of pipe
- kind of water to be pumped
- storage tank available (recommended)
- static water level (m)
- dynamic well characteristics (m at m³/h)
- well diameter
- water quality
Other
- tank height
- tank volume
- volume of required water/day
- seasonal variations (e.g. rain season)
- distance (horzontal) between well and tank
- piping on site (total length, diameter)
- power supply (PV direct or indirect via battery)
