Solar Radiation at the Earth’s Surface

The Earth receives 122 PW (1.070 EWh per year) of solar energy at its surface. The Sun offers 7,500 times more energy than the entire anthropogenic demand. We would need to tap into just 0.013% of available solar energy (0.44% over land) to replace all other energy sources.

The electromagnetic radiation of the sun can be used by photovoltaic plants or solar collectors to generate heat or electricity.

When the solar radiation arrives at the earth’s atmosphere, the average intensity is 1,367 kW / m2 (solar constant). After reflection, absorption, and conversion processes as the sunlight passes through the atmosphere, an average of about 330 W/m2 (24% of the solar constant) is incident at the earth’s surface over 12 hours per day.

Humans consumed 505,000 petajoules primary energy in 2010. 17% of this was for electricity generation. The market value of global energy consumed in 2015 was approximately 9.1 trillion US dollars.

    Useful facts:
  • Total surface area of the Earth: 510,000,000 km²
  • Water surface: 360,570,000 km² (70.7 %)
  • Land surface: 149,430,000 km² (29.3 %)
  • Surface used by agriculture: 48,827,330 km² (9.6 %)
  • Area covered by forest: 40,204,320 km² (7.9 %)