If we needed 10x the concrete, we wouldn’t have built so many cheap ugly concrete buildings.

Putting solar panels over parking spaces is a terrible idea - it’s far more expensive, makes it far more liable to be smashed by some idiot, and requires high-embodied-emissions steel/concrete to car-proof your solar panels as a result (technically just car-resistant).

Meanwhile, car parks are a stupid symptom of car-centric design and should be phased out. Putting solar panels on a car park isn’t smart use of space, it’s just putting lipstick on a pig.