Solar on farmland: planning, not technology

Dr Madhur Gupta attributes the conflict between solar plants and land use to planning rather than to the technology. He argues that covering entire stretches of fertile farmland raises food security and farm income questions, and that car parks, commercial rooftops, motorways, railway corridors and canals could host the generation.

One country has turned that idea into a legal obligation. In France, article 40 of the renewables acceleration law of 10 March 2023, implemented by Decree 2024-1023, requires solar canopies over half the surface of outdoor car parks above 1,500 sq m, with deadlines of 1 July 2026 above 10,000 sq m and 2028 for the rest, under an annual fine of 20,000 to 40,000 euros.

The obligation settles the siting question and moves it to financing. A canopy costs more per watt than a ground-mounted plant, and the car park owner rarely wants the asset, which opens room for a developer to carry the investment in exchange for a long contract over the area.

The French case shows that the land-use conflict has a regulatory answer when the deadline carries a sanction. That design is what creates a market for surface leases, and it is the site contract that makes the investment viable.