The sun delivers 89 petawatts of power to the Earth’s surface every year. It is about 6000 times more than the global population needs (about 15 terawatts). About 1% of this power is transformed into the wind energy. The whole wind power reaches 900 terawatts (60 times more than the global demand). Some of the power induces water evaporation which then falls back onto the land surface as precipitation and forms rivers. The power of rivers which can be used to generate energy is estimated at 7.2 terawatts (approximately 50% of the global demand). The geothermal energy is generated by breakdown of radioactive isotopes inside the Earth. Its powers is estimated at about 46 terrawatts.
The use of renewable energy resources depends on its concentration. Even though the most abundant energy source is the Sun, it is also the most dispersed. Out of one sun-lit square meter in the zenith, only 1 kilowatt of energy can be generated. Wind energy can be more concentrated and a single wind turbine can have the power of a few megawatts. Hydro power plants which use water falling from a large area can generate power of gigawatts.
This material has been published thanks to the financial support of the National Fund for Environmental Protection and Water Management. The sole responsibility for its contents lies with Collegium Mazovia.