solar cells

Let's use solar energy! How large does the area need to be?

Our society consumes quite large amount of energy, mostly relying on fossil-fuels, and our demand of energy shall keep increasing as a whole. To supply the energy demand in coming future, renewable energy needs to be utilized (see The amount of energy we consume). Thinking of sunlight as a model, one may notice that energy amount depends on the area of irradiation. Let's see in this post how large the area needs to be to supply the energy to the world.