Technical, economic, and environmental modeling of solar water pump for irrigation of rice in Mazandaran province in Iran: A case study

In this study, the required pumping power and number of PV modules for a photovoltaic water pumping system (PVWPS) were determined with the aim of supplying the water demand in a rice paddy located in north of Iran. Also, a battery bank was utilized as a backup system to increase system reliability in autonomy days. The idea of using PVWPS during non-irrigation months of the year in order to earn money through the sale of electricity generation from solar panels to the grid is one of the main objectives of this research which has not been considered in the previous works. Also, in this research, economic and environmental aspects about PVWPS have been performed and the system performance has been compared with conventional diesel pumping systems (CPS). The results show that although the initial cost of PVWPS in off-grid mode is 2.14 times of the CPS initial cost, its operating and maintenance costs and total life cycle cost (LCC) are respectively 8.7 times and 29.9% lower than that of costs of CPS. Also, the initial cost of PVWPS in the on-grid mode is slightly more than about 2.41 times of the cost of the initial CPS, but its O & M and LCC costs are 7.25 times and 16% lower than those for CPS, while in the case of selling electricity to the grid, it could generate income of $ 8212 in project lifetime, which is equivalent to 59.9% of LCC of the system and results in reducing the costs by 189.2% compared with the final cost of the CPS. Additionally, from environmental viewpoint, the results showed that CO2 production for off-grid PVWPS during the lifetime of the project is 190-201 times lower than that for the CPS and compared with the supply of power to the motor pump from the grid, CO2 emissions reduced 16.96 times. Also, by replacing the CPS with PVWPS during irrigation period, it can save about 1820-1722 L of diesel fuel and 85 L of engine oil. Additionally, in on-grid operation, the PVWPS leads to about 71% reduction in noise production than CPS. (C) 2019 Elsevier Ltd. All rights reserved.