France’s plan for solar panels on all car parks is just the start of an urban regeneration revolution

France has passed a law requiring all parking lots with more than 80 seats to be covered by solar panels. This is part of a broader program that will see solar panels occupy derelict, vacant lands along roads and railways, as well as some farmland.

This is expected to add 11 gigawatts to the French grid equal to ten nuclear reactors.

Do the numbers add up? And should other countries do the same?

Several countries, most notably Germanyasked developers of new buildings to incorporate renewable energy into their designs, such as roof-mounted buildings Solar power panels, biomass boilers, heat pumps and wind turbines. The French policy will apply to new and existing car parks.

The average car parking area is about 4.8m x 2.4m, or 11.52m². Suppose an output of 120 watts per square meter operates at about 1.4 kilowatts of power per compartment. There will be more space on footpaths and traffic lanes in the parking lot, but the solar panels will need to be spaced far enough apart to prevent them from shading each other.

To get 11 gigawatts of capacity, you need to accommodate about 7.7 million car parking spaces. Are many people in France eligible? Great Britain has from 3 to 4 million spaces and 40 million won vehicle. France has a similarly sized fleet of 38 million won. So the 7.7 million space seems unlikely.

But the law covers a lot of urban land, not just parking lots. In theory, France’s 92km² of urban land (defined as any built-up area with more than 5,000 people) could provide 11 gigawatts of solar power.

That sounds like a lot, but it only accounts for 0.106 percent of France’s total urban land area 86,500 km². Taking into account the difference in power factor (the amount of energy each source produces a year compared to its maximum theoretical output) between the French nuclei (70%) and French solar (15%), 430 km of solar will provide the same amount of electricity per year in gigawatt hours as ten Nuclear power factory.

These sheets need to cover only 0.5% of French urban land, or about 0.07% Total area of ​​France. So it’s possible, although the parking lots will make up a very small part of the entire program.

Go to a parking lot near you

The UK and countries further north receive less sunlight per m and the sun is lower on their horizon, which makes the problem of shading on the panels worse. larger, although the longer days in summer make up for this to some extent.

Also, while a lot of parking lots in Southern Europe already have sunshades (allowing to mount solar panels on existing structures), this is rare in cooler countries. As a result, it would probably be a lot easier to mount the panels on the roofs of buildings than on the surrounding parking lots in some countries. When solar panels are impractical, other options, like wind turbines, can be viable alternatives.

Likewise, some parking lots, especially those in the city center, are shaded most of the day by nearby tall buildings. But instead, there’s no reason not to put the panels on top of them.

France is likely to pursue this policy to reduce its dependence on nuclear energy, which provides 70% electricity of the country. This arrangement works when demand is stable. It becomes a problem when, for example, a drought forces many factories to reduce power output or Turn off. France is also adding several million electric cars and heat pump to its grid, which will need to draw from a variety of energy sources and storage options.

The UK is similarly dependent on gas for both electricity and heating. Creating a more diverse energy supply, much of it directly connected to the cars or homes that consume that energy, makes a lot of sense. But a strategy to unleash the green energy potential of empty space in towns and cities should begin—not end—with parking lots.

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