Solar power on irrigation canals: A dual solution for energy and water conservation

ACROSS the world, solar power has emerged as one of the fastest-growing sources of clean energy.

- By Henry Gamage

Canal-top solar: Turning infrastructure into opportunity

It is environmentally friendly, increasingly cost-competitive, and particularly well suited to tropical countries with abundant sunshine.Recognising this global transition, Sri Lanka has set ambitious national targets: generating 70 percent of electricity from renewable sources by 2030 and achieving carbon neutrality by 2050.

Sri Lanka is naturally well endowed for solar energy generation. The country receives abundant sunlight throughout the year, especially in the dry zone, where solar radiation ranges between 4.0 and 6.0 kWh/m²/day. This provides a strong foundation for meeting a significant share of daytime electricity demand through solar power.

Solar energy also complements Sri Lanka's existing hydropower system. Daytime solar generation can reduce pressure on hydropower plants during peak daylight hours, allowing valuable reservoir storage to be conserved for nighttime generation and drought periods. Such integration improves grid reliability while strengthening national water security, an increasingly critical concern under climate change.

Despite its potential, large-scale solar development faces a major constraint, which is land availability. In Sri Lanka, land is intensively contested among agriculture, forest conservation, settlements, and industrial development. Allocating vast tracts of land for solar farms often creates social, environmental, and political tensions.

If Sri Lanka is to meet its renewable energy ambitions without compromising food security or ecosystems, innovative solutions that minimise land acquisition are essential.

One promising solution is the installation of solar panels over irrigation canals. This concept, already implemented successfully in several countries, converts existing infrastructure into dual-purpose systems, generating clean energy while simultaneously reducing water losses from evaporation.