ECONOMIC AND TECHNICAL PERFORMANCE OF SOLAR IRRIGATION PUMPS IN THE CAUVERY DELTA REGION, TAMIL NADU

Abstract

Solar photovoltaic (SPV) irrigation pumps are emerging as a sustainable alternative to conventional irrigation technologies in tropical rice-based farming systems. This study evaluates the growth dynamics and farm-level efficiency impacts of solar irrigation pumps in the Cauvery Delta Region (CDR) of Tamil Nadu, India, covering the districts of Mayiladuthurai, Tiruvarur, and Thanjavur. Secondary data on solar, electric, and diesel pump installations from 2005–06 to 2023–24 were obtained from TANGEDCO and TEDA, while primary data were collected from 360 paddy farmers (Solar: 180, Electric: 90, Diesel: 90) across 18 villages during 2023. Compound Annual Growth Rate (CAGR) analysis revealed rapid expansion of solar pump adoption, increasing at 38.7% annually over the study period and accelerating to 52.9% following the introduction of the PM-KUSUM scheme. In contrast, diesel pump installations declined at an annual rate of 8.2%. Chow tests confirmed significant structural breaks in pump adoption trends after PM-KUSUM implementation. Farm efficiency was assessed using Data Envelopment Analysis (DEA) and Stochastic Frontier Analysis (SFA). Mean technical efficiency scores under the CCR model were highest for solar pump users (0.868), followed by electric (0.794) and diesel farmers (0.714), with statistically significant differences among groups (p<0.001). SFA results further confirmed superior performance of solar pump users, as indicated by a significant negative inefficiency effect, while diesel pumps were associated with higher inefficiency. The gamma value (γ=0.732) suggested that most output variation below the production frontier was attributable to technical inefficiency. The findings demonstrate that solar irrigation enhances resource-use efficiency and reduces energy-related production constraints, supporting policies that promote renewable energy adoption in irrigated rice farming.