India’s vast canal network offers a land-free path to solar power

Why in the News

The Centre has approved the PM Surya Sarovar Yojana (PM-SSY). The scheme aims at developing 5,000 MW of floating solar capacity on reservoirs and other inland water bodies across the country. The approval follows a steady rise in the cost and difficulty of acquiring land for large-scale solar projects. India’s canal network, one of the largest in the world, carries a second land-neutral option in canal-top photovoltaics (CTPV), meaning solar panels mounted on elevated structures built over canal stretches. A 2024 assessment placed India’s combined canal-top and canal-bank potential at around 131 GW. Deployment has stayed limited for more than a decade after the first installation, so the binding constraint on canal-top solar is system cost and structural design rather than resource availability.

What is canal-top photovoltaics?

1. Structures built over the canal: CTPV mounts solar panels on specialised structures erected over canal stretches. The canal itself becomes the site, so no separate plot is acquired.
2. Difference from floating solar: A floating system places panels on floating platforms on a water body. CTPV instead uses elevated structures standing above the canal.
3. Design set by canal geometry: A system is built to the canal’s width, design and orientation. The elevated structure may span the canal or sit along the canal banks.
4. Unobstructed water flow: Every design must leave the canal’s water flow unobstructed.

What does covering a canal deliver beyond electricity?

1. Land neutrality: CTPV requires virtually no additional land. Eg. In Punjab, the installation of 20 MW of canal-top systems is estimated to have saved nearly 100 acres of land.
2. Reduced evaporation loss: Panels covering a canal stretch cut the amount of water lost to evaporation. The gain matters most in India’s water-stressed regions.
3. Cooling effect on panel output: The water beneath the panels cools them. Panel performance in hot weather improves as a result.
4. Measured dual output: A 1 MW system over the Narmada Canal at Mehsana in Gujarat saves close to 9 million litres of water every year. It generates 1.6 million units of electricity annually.

How far has deployment actually gone in India?

1. Early adoption: India’s first canal-top installation was commissioned at Mehsana in Gujarat in 2012. The country was an early adopter of the technology.
2. Gujarat and Punjab capacity: Two 10 MW systems were commissioned in Vadodara, Gujarat, between 2014 and 2017. Punjab commissioned 20 MW of canal-top systems between 2017 and 2018.
3. Punjab’s current pipeline: The Punjab Energy Development Agency invited expressions of interest in September 2025 for 40 MW of canal-top projects. The State’s canal network spans over 10,000 km.
4. Haryana’s exploration: Haryana has initiated efforts to explore canal-top systems over six of its irrigation canals.
5. A niche after a decade: CTPV remains largely a niche application, and deployment has stayed limited for more than a decade after the first installation.

What does the assessed potential show about where canal-top solar can scale?

1. Assessed potential: A 2024 assessment estimated India’s canal-top and canal-bank potential at around 131 GW.
2. Scope of the estimate: The estimate covers canals up to 30 m wide. It assumes vertical bifacial installations for canals over 30 m wide.
3. Screening criteria: Solar irradiation, canal characteristics, distance from substations and protected areas were applied to identify the best-suited canal stretches across India.
4. Leading States: Uttar Pradesh, Bihar, Karnataka, Andhra Pradesh and Punjab carry the highest potential.

Why has a decade of policy support not converted pilots into scale?

1. The 2014 pilot scheme: The Ministry of New and Renewable Energy (MNRE) launched a pilot-cum-demonstration scheme for grid-connected canal-top and canal-bank projects in 2014. It set a target of 50 MW each for canal-top and canal-bank projects.
2. Financial assistance offered: The scheme offered Rs 3 crore per MW for canal-top systems and Rs 1.5 crore per MW for canal-bank systems. The assistance was capped at 30% of project cost, whichever was lower.
3. Limits of financial assistance: The 2014 scheme shows that financial support by itself does not convert pilots into large-scale deployment.
4. Floating solar as the new policy signal: PM-SSY is expected to revitalise the floating solar segment and drive its adoption across India. That policy interest in land-neutral solar can extend to canal-top systems.

Challenges to canal-top photovoltaics

1. High system cost: Elevated structures spanning a canal need additional structural steel, foundations and access provisions, so canal-top systems cost more than ground-mounted ones. Eg. High system cost is the primary bottleneck behind a deployment record of a few tens of megawatts since 2012.
   The Fix: Route early projects through viability gap funding and low-cost debt, so developers build experience and cost falls through scale and standardisation.
2. Structural design against canal operations: The structures must avoid disrupting canal operations and must withstand winds. Eg. A design spanning an irrigation canal has to clear the water flow and carry maintenance access at the same time.
   The Fix: Issue standardised specifications and guidelines for canal-top structures, so each developer does not engineer the same span from scratch.
3. Maintenance on a working canal: Cleaning panels, replacement and repair are difficult on structures elevated above a canal that is in use. Eg. The two 10 MW systems at Vadodara sit over live irrigation canals.
   The Fix: Build operations and maintenance access into the design standard rather than leaving it to each project’s own layout.
4. Linear layout and evacuation distance: A canal-top system runs along the canal’s course, so irregular paths and changes of direction raise the cost of electricity where substations or transformers are not close. Eg. Punjab’s canal network runs over 10,000 km across the State.
   The Fix: Select and prioritise canal stretches on land scarcity, nearby electricity demand, grid connectivity and canal geometry before capacity is tendered.
5. Institutional coordination: A canal-top project sits across a State nodal agency and an irrigation department, each with its own approval process. Eg. Haryana’s exploration covers six irrigation canals under its irrigation administration.
   The Fix: Attach capacity building of State nodal agencies and irrigation departments, plus streamlined process flows, to any renewed canal-top scheme.

Conclusion

Land-neutral solar has moved from demonstration to a funded national scheme in the floating segment, and canal-top solar sits one step behind it. The obstacle is not the size of the resource or the absence of a subsidy, both of which have been established for years. It is the cost of building over a working canal and the absence of a standard way of doing it. The measure to watch is whether any renewed canal-top support carries standardised specifications and State agency capacity building alongside the money, since money on its own has already been tried once.

Matching Previous Year Question

“[2015, GS3, 12.5 marks] To what factors can be the recent dramatic fall in equipment cost and tariff of solar energy be attributed? What implications does the trend have for thermal power producers and related industry?”