STEAM-POWER

First written document about steam engines are nearly two millenniums old, written by Hero of Alexandria. However, Thomas Savery had developed first useful steam engine at 1689. The steam engine was the ultimate power source for first industrial revolution, since it has been replaced by electrical motors and combustion engines at the beginning of the 20th century. However, the steam turbine, an alternative form of steam engine, has become the most common method by which electrical power generators are driven. At 1996 even 90 % of the whole amount of electrical power in USA has been generated by steam turbines.