Solar Tube well (Solar Powered water pumping systems) is now one of the most popular industries in Pakistan, Epically in Punjab and Sindh Province. The reason of popularity of solar powered water pumping system is lack of dams and so canal water is not sufficient to fulfil the needs of irrigation of our agricultural lands. The higher prices of electricity and unavailability of electricity in rural areas lead farmers to use diesel generator or peter engines. But maintenance cost is pretty much higher. The success of solar powered tube well is a new hope for the farmers of Pakistan.
But there are some necessary information is required to install a viable solar system to run a tube well. Most of the areas of our country are capable to produce 5.3 kWh/m²/day energy which is 10 times higher than Germany.
Solar-based water pumping system can be DC or AC operated. DC water pumping system is somewhat cheaper but not applicable in case of larger water-pumping system. I.e. three phase water pumps. Solar-Powered pumping systems (called tube wells in Pakistan) consist of three basic components:
1. Solar Panels (Photovoltaic Module)
There are two type of Solar Photovoltaic technologies available worldwide (Amorphous and Crystalline). Amorphous or Thin-Film solar modules are more likely used and recommended for solar-powered tube-well as they are single cell module, low power loses because of higher temperature tolerance range, have longer lifespan and ideal for low-light or cloudy weather condition. But due to less conversation efficiency(less than 10%) this type of panels requires more space, more solar panel stand and more wiring expense. Crystalline solar panels have two types Mono and Poly.
Few peoples are confused that what panel is good in performance. The answer is simple. Do not go into comparison of mono and poly. Just make sure that the panel you are going to buy is certified by TUV labs and meet the standard of ISO and IEC etc.
2. Inverter (MPPT Controller/Water pumping inverter/Soft Starter/VFD)
An inverter’s elementary purpose is to change DC (Direct current) energy into AC (Alternate current). Usually this technique is used where we tend to operate 3phase water-pumping system. Inverter contains MPPT (Maximum Power Point Tracking, software or hardware based) charger and pump controller in it. This method doesn’t require batteries run the system. That is why; this system starts working from rise of sun and performs until sunset. The operation mode can be manual start or automatic
3. Water Pump (Horizontal Centrifugal/Turbine Pump/Submersible Pump)
Water pump is third basic component. In longer depth of water areas, submersible water pumps are considered as most energy efficient with maximum water outlet delivery. World renowned submersible water pump manufacturers are Saer (Italy) and Grundfos (Germany) and Lorentz. However horizontal centrifugal pumps are feasible and more efficient in lower depth of water.
The running cost and maintenance cost of Solar water-pumping system is almost zero.Also Safe, simple and reliable and quire operation gives real peace of mind.