Canal-Top Solar Photovoltaics (CTPV)

Why in News?

India is exploring Canal-Top Photovoltaics (CTPV) to expand solar power while saving land and reducing water evaporation through its extensive canal network.

What is Canal-Top Photovoltaics?

• CTPV – It involves installing solar panels on elevated structures above irrigation and water-supply canals.
  • Unlike floating solar, panels are mounted on structures rather than floating on water.
• Structures are designed according to canal width, orientation and geometry while ensuring uninterrupted water flow.
• Potential of CTPV in India – A 2024 assessment estimated India's combined CTPV and canal-bank solar potential at around 131 GW.
  • Potential was assessed considering:
    • Solar irradiation
    • Canal characteristics
    • Grid connectivity
    • Distance from substations
• Protected areas – States with the highest potential include:
  • Uttar Pradesh
  • Bihar
  • Karnataka
  • Andhra Pradesh
  • Punjab

What are the Advantages of CTPV?

• Saves Land – Uses existing canal infrastructure and requires virtually no additional land.
  • A 20-MW installation in Punjab is estimated to have saved nearly 100 acres.
• Conserves Water – Solar panels provide shade over canals and can reduce evaporation losses, particularly valuable in water-stressed regions.
• Improves Solar Performance – Water beneath the panels can provide a cooling effect, potentially improving panel efficiency during hot conditions.
• Supports Renewable Energy Expansion – Enables additional solar generation without competing significantly with agricultural and other land uses.
• Multiple Use of Existing Infrastructure – Converts existing irrigation infrastructure into energy-generating assets, supporting the broader land-neutral energy transition.

What are the Challenges in Scaling CTPV?

• High Capital Cost – CTPV is generally more expensive than ground-mounted solar. Elevated structures require additional Structural steel, Foundations, infrastructure.
• Difficult Maintenance – Cleaning, repair and replacement of panels become more difficult because installations are elevated above operational canals.
• Canal Geometry – Irregular canal paths and changes in direction can increase construction and power-transmission costs.
• Grid Connectivity – Distance from substations and transformers can reduce economic viability.
• Institutional Coordination – Projects require coordination among renewable-energy agencies, irrigation departments, State governments and distribution companies.

What is the Way Forward?

• Identify Suitable Canal Stretches – Prioritise locations based on Solar potential, Canal geometry, Land scarcity, Electricity demand, Grid connectivity.
• Provide Viability Gap Funding – Use low-cost finance and viability gap funding to overcome high initial costs.
• Standardise Designs – Develop standard technical specifications for structures, safety, and maintenance and canal operations.
• Strengthen Institutional Capacity – Build capacity among State nodal agencies, irrigation departments and DISCOMs.
• Promote Public-Private Participation – Encourage private investment through predictable policies and long-term project frameworks.
• Scale through Learning – Use pilot projects to develop standardised designs, reduce costs and improve maintenance practices.

What lies ahead?

• Canal-top photovoltaics can help India pursue the energy transition without intensifying competition for land and water.
• Although higher costs and maintenance challenges limit large-scale deployment, better institutional coordination can unlock its potential.
• CTPV should complement—not replace—rooftop, ground-mounted and floating solar, forming part of India's diversified renewable-energy strategy.

Reference

The Hindu| Canal-Top Solar Photovoltaics (CTPV)