The sun – inexhaustible energy source

At present only a small part of the world’s energy demand is covered by solar energy. However, as fossil fuels such as oil become more and more expensive, it is inevitable that renewable energy sources will be used more and more. Photovoltaics has the greatest global potential here, as solar radiation is available in unlimited quantities and the raw materials for the solar cells (usually silicon) are also very readily available.

In Bavaria, 5 % of the annual energy demand is already covered by photovoltaics, and in summer this figure rises to around 40 %. This example shows that a greater use of solar energy is possible through appropriate subsidies and political framework conditions.

Solar energy in numbers:
Energy radiation of the solar surface about 75.000 kW/m²
Irradiance on the earth's surface averages about 1 kW/m², 
from 50 W/m² with a very cloudy sky 
to about 1,200 W/m² with optimal cloud cover
Irradiated energy quantity per year in Austria: 
1,000 to 1,400 kWh/m²a
Maximum solar radiation: 2,200 kWh/m²a 
(areas in Australia, South and Central Africa, America)
The solar radiation corresponds to about 10,000 times 
the current primary energy consumption of mankind.
(Source: http://kurse.ibo.at/mod/scorm/player.php?a=20&currentorg=eXesanieren_24823c6301d864942c32&scoid=466)