Hybrid Solar WAPDA Irrigation System

Project Title

Hybrid Solar WAPDA Irrigation System

Project Area of Specialization Electrical/Electronic EngineeringProject Summary

Pakistan is primarily an agriculture country with the capability of producing wheat, cotton, sugarcane and rice, which together are more than 75% of the total crop output. Underground water is the main source of irrigation. Most of the water pumps use diesel generator while others run on electricity. The diesel is very expensive and electric supply situation is very unreliable in Pakistan. Photovoltaic (PV) powered water pumps are an attractive alternative solution, but due to the high cost of solar panels, they are not within the reach of a common farmer. In this paper, a novel architecture for an irrigation water pump, simultaneously powered by utility and PV panels, is proposed. No battery backup is required. The system employs maximum power point tracking. The pump controller receives a single control input to produce desired water flow rate and concurrently maximizing the utilization of PV resource. The proposed solution allows the farmer to incrementally add solar panels to an existing grid powered pumping system, thereby reducing the initial investment required for full solar deployment. The investment in the partial deployment of solar panels is paid back to the farmer in reduced electricity tariff.

Project Objectives

The objective of this project is to provide a reliable and economical solution for water pumping. A novel hybrid solar/WAPDA irrigation water pumping system is investigated in this report. The solution works with any installed solar capacity with existing grid powered pump, thus reducing initial investment, while decreasing their long-term energy costs, thus balancing economic development and environmental sustainability.

Project Implementation Method

In this system, each PV panel output is extracted through a MPPT DC/DC converter in order to get maximum power from PV panels. If the sun radiation on one PV panel decreases, it does not affect other solar panels, because each PV panel has an independent MPPT controller, thus avoiding partial shading effects. WAPDA AC power is converted to DC by a three-phase rectifier. The outputs from DC/DC converter and three-phase rectifier are connected to common DC bus. This DC voltage is used to drive a three-phase voltage source inverter, which provides the power to the motor. The motor speed is regulated for a given flow rate using variable frequency inverter. This is an efficient way of driving motor according to desired flow rate. At daytime, solar power is utilized, and WAPDA power is saved, thus saving electricity bill. So, an optimal way is developed and tested to drive motor, partially powered by solar panels, while taking remaining power from the WAPDA. The combined WAPDA and solar powered pumping system is the best solution for varying insolation. When the insolation level decreases, the MPPT tracks the new maximum power point (MPP) and WAPDA supplies the remaining power for required power demand. When the insolation increases, the MPPT tracks the new MPP, and in this case, power from utility decreases. If solar power is zero, then the motor will run on WAPDA power.

Benefits of the Project

The average availability of electricity from the grid is around 8–12 h per day in rural remote areas. Due to the current energy crisis and high electricity tariff, the agriculture sector in Pakistan having groundwater as the source of irrigation is badly affected. Therefore, an efficient, reliable and cost-effective energy solution for the agriculture sector in Pakistan is needed for irrigation. The solar water pumping system is the promising solution for irrigation. It is a clean, environmentally friendly and reliable source of supplying water that requires low maintenance. It has no running cost and long life as compared to a diesel generator. The amount of power extracted directly from solar panels is not sufficient, in terms of voltage and current, for running water pumping motor. The power electronic converter plays important role in system configuration. Different power electronic converters are used for maximum energy harvesting. The maximum power point tracking (MPPT) is used for extracting maximum energy from photovoltaic (PV) panels. MPPT is a not a physical tracking mechanism but an electronic method to operate PV panel at the optimal point. The DC–DC converter is employed for MPPT. The single stage water pumping configurations require the only inverter connected directly with PV panel cutting the cost of DC– DC converter. However, the inverter is responsible for both motor speed control and MPPT.

Technical Details of Final Deliverable Final Deliverable of the Project Hardware SystemCore Industry AgricultureOther Industries Manufacturing Core Technology Clean TechOther TechnologiesSustainable Development Goals Affordable and Clean EnergyRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	68000
PV SOLAR PANNEL	Equipment	1	17500	17500
1 HP Induction motor	Equipment	1	13000	13000
Rechargeable battery 37.5 AH	Equipment	1	25000	25000
To design Maximum Power Point Tracking for Solar Plate and for VFD	Equipment	2	5000	10000
To design Flyback converter for Solar Plate	Equipment	1	2500	2500