Why in News?

Rising costs and difficulty of land acquisition for large-scale ground-mounted solar projects have renewed interest in Canal-Top Photovoltaics (CTPV) as a land-neutral renewable energy solution, aligning with initiatives like PM Surya Sarovar Yojana (PM-SSY), PM-KUSUM, and the National Solar Mission.

What is Canal-Top Photovoltaics (CTPV)?

  • Definition: Solar panels mounted on specialized elevated structures built over irrigation or water-supply canals.
  • Difference from Floating Solar: Floating solar uses panels on pontoons on reservoirs/lakes; CTPV uses static elevated structures spanning the canal.
  • Design: Structural geometry is engineered per canal width and orientation, keeping water flow completely unobstructed.

Key Benefits

  • No additional land: Bypasses land acquisition — a 20 MW CTPV plant in Punjab saved ~100 acres.
  • Water conservation: Shading reduces evaporation — a 1 MW system over the Narmada Canal (Gujarat) saves ~9 million litres annually.
  • Enhanced efficiency: Cooling effect of flowing water improves generation in extreme heat.
  • Reduced maintenance: Less sunlight limits algae and weed growth.
  • Multi-functional infrastructure: Combines water management with localised power generation.

Current Status and Potential

  • First installation: 1 MW at Mehsana, Gujarat (2012) — India was a pioneer.
  • Followed by 20 MW in Vadodara and 20 MW in Punjab (2014–2018).
  • Potential: A 2024 CSTEP assessment estimated 131 GW of CTPV and canal-bank solar potential.
  • Top prospective states: Uttar Pradesh, Bihar, Karnataka, Andhra Pradesh, Punjab.
  • Recent developments: Punjab invited EoIs for 40 MW across its 10,000 km canal network (Sept 2025); Haryana is evaluating CTPV over six major canals.

Major Challenges

  • High capital expenditure: Elevated, wind-resistant structures cost more than ground-mounted solar.
  • Complex maintenance: Panel cleaning, repairs and canal desilting are difficult under covered canals.
  • Grid connectivity: Linear canal layout raises power evacuation costs far from substations.

Pradhan Mantri Surya Sarovar Yojana (PM-SSY)

  • Type: Central Sector Scheme for Floating Solar Photovoltaic (FSPV) capacity on inland reservoirs.
  • Target: 5,000 MW by FY 2030-31; outlay of ₹5,070 crore.
  • Storage mandate: Co-located BESS with minimum two-hour storage (10,000 MWh total).
  • Financial support: CFA of ₹1 crore/MW on commissioning + up to ₹50 lakh/project for feasibility, bathymetry and environmental studies.
  • Benefits: Saves agricultural land, cuts reservoir evaporation, reduces ~10 million tonnes CO₂ annually, creates ~16,000–17,000 green jobs.

Significance for India

  • Supports India's renewable energy targets and land-neutral solar expansion.
  • Addresses the land-water-energy nexus, critical for water-stressed agrarian states.
  • Converts existing irrigation infrastructure into dual-purpose assets.