Modeling Large Scale Solar Irrigation Deployment: Costs and Grid Implications in Rwanda

Paper in proceeding, 2025

Electrifying irrigation through solar photovoltaic (PV) systems offers a dual benefit of boosting agricultural productivity and relieving stress on national electricity grids. This paper presents a spatially and temporally explicit technoeconomic model to assess the integration of solar-powered irrigation in Rwanda, comparing behind-the-meter (BTM) and utility-scale deployment strategies. The analysis evaluates total system cost, grid demand, and export compensation across varying PV capacities and irrigation scales. Results reveal significant cost savings at moderate PV sizing, but diminishing returns and rising export burdens at higher capacities. Breakeven export tariff thresholds are identified, indicating the point at which BTM solar becomes less cost effective than baseline grid supply. The study finds that utility-scale solar with grid-charged gravity storage offers lower initial system costs, while BTM configurations become competitive under supportive export regimes. These findings provide actionable insights for policymakers seeking to align solar irrigation incentives with grid affordability and national electrification goals.