Groundwater irrigation underpins South Asian agriculture but is increasingly unsustainable. Solar irrigation pumps (SIPs) are promoted to cut carbon emissions and subsidy costs, yet concerns persist about over-extraction. This study, under the SDC-supported SoLAR project, assesses two models: fee-for-service SIPs in Bangladesh and grid-connected SIPs in India. Results show no significant rise in groundwater use with solar adoption in these two models. In Bangladesh, operator-managed SIPs kept use in check despite cheaper costs, though some shift toward Boro paddy was noted. In India, grid-connected SIPs with feed-in incentives reduced water use in alluvial aquifers, while hard-rock systems showed little change. The findings highlight that groundwater impacts are context-specific, with well-designed solar models offering low-carbon irrigation without major sustainability risks.
