Global solar resources

In just six months, the sun delivers as much energy as is available in all of Earth’s non-renewable energy resources combined (oil, coal, gas, uranium).

The most inhabited areas of the Earth’s surface receive between 150 and 300 watts per square metre of solar energy (insolation). 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.

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. Most of the world’s population live in areas with insolation levels of 150–300 watts/m², or 3.5–7.0 kWh/m² per day.

The total solar energy absorbed in one year by Earth’s atmosphere, oceans and land masses is approximately 3,850,000 exajoules. In one hour and 15 minutes, the Sun delivers more energy than humans use in a year (505 EJ). 17% (86 EJ) of human primary energy consumption is for electricity generation. The market value of global energy consumed is approximately 9.1 trillion US dollars per year.

Photosynthesis utilises c. 3000 EJ of the sun’s energy for biomass creation.

    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 %)