A diverse framework for optimization and techno-economic evaluation of PV Mini-grids for sustainable future of agricultural irrigation

The deployment of a solar (PV) mini-grid has been proposed as a solution for generating and distributing electricity to meet irrigation requirements. This study offers engineering solutions and meticulous economic evaluation necessary for the implementation of photovoltaic mini-grids for agricultural irrigation. The proposed irrigation network is powered by a 3–4 MWp photovoltaic plant in conjunction with diesel generators. Considering the cropping pattern, a 4-MWp system is deemed more feasible for irrigation, yielding a 20 % higher NPV of 3.6 million USD compared to the 3-MWp solar system, which has an NPV of 3.0 million USD. Various PV orientations with different installation mechanisms have been analyzed for 4-MWp capacity, leading to the recommendation of installing a fixed-tilt PV plant oriented towards the south to meet the operational load requirements. The fixed tilt south-facing PV plant determines a performance ratio of 83.39 %, LCOE of 14.7 USD/MWh, and achieves a payback period of 3.18 years. On the other hand, the east-facing PV plant has a performance ratio of 83.8 %, LCOE of 15.3 USD/MWh, and a payback period of 3.37 years. Over the year, a 4-MWp PV system has significantly higher utilization than a 3-MWp system and can save 307,303 l of diesel every year. Furthermore, a load flow study is carried out utilizing the OpenDSS software, comprehensively determining the current and voltage requirements at each point along the voltage lines. During the simulation analysis, when the maximum load is connected with a centralized mini-grid, the voltage drop from the grid to the end of a transmission line is within the 10 % limit (only 3 %) at the maximum load. According to the loss calculation analysis, total load power is 3294.4 kW, line losses are 40.1 kW, and percent losses for the circuit is 1.22 %. For the case when maximum load is connected with PV plants at 2 different locations, another 1-MW PV plant in addition to the 4-MW main plant is assumed to be installed near the end of the distribution system. The results indicate a minor improvement in total load power (3294.5 kW) and a reduction in line losses (39.5 kW) reflecting the unnecessary requirement of the additional system at this stage, thereby endorsing the efficiency and effectiveness of the designed main distribution system. To promote similar installations for agriculture irrigation, this study offers a holistic methodology and in-depth analysis that are applicable on a global scale.