Let’s assume that the Sun is a point source of radiant energy, which radiates a total power of about 4 x 1026 W into space. This energy is smeared out over a surface area of a sphere 150million km in radius.
On an annual basis, this energy reaching the Earth surface is 3.2 million EJ/y, which is close to 7000 times global energy consumption. If we could harvest even a small fraction of this energy we could solve all our energy problems. Global energy consumption last year was 0.0015% of emitted solar radiation reaching the Earth’s surface and projected global consumption in 2100 is 0.051%. We should therefore expect that we should have the technology to harvest enough solar energy to replace harmful fossil fuels.