In much the same way that Watt’s condensing steam engine vastly increased the value of Newcomen’s engine, the steam turbine vastly improved the value of Edison’s electric factory.
Steam turbines allow steam, generated by heating water, to efficiently turn generators, usually to make electricity. In addition to steam, water (ex: waterfalls) or wind (ex: windmills) can drive turbines.
Watt and similar steam engines would use the pressure of steam to move the engine. Simplifying, pressure would build up to tip a bucket that would drive a crankshaft converting the movement into energy, similar to how a river drives a water wheel. Typically, gravity (though, in later models, steam) would then return the shaft so the process could repeat. These engines had a lot of power but ran at a slow speed.
Electrical generation, however, requires less power but higher speeds to turn the generator. Steam velocity spins generators rather than steam pressure. Yet steam velocity is very fast and would quickly cause any system, especially one built of 1800’s era metals, to fall apart. There were no metals that could withstand the centrifugal force of steam velocity.
In response, Parsons created a series of blades, each larger than the next, which spin at their own manageable speed. The slower but collectively more powerful spinning is due to capturing the steam velocity as it expands. The steam turbine is still in use today to generate electricity.
Jet engines use a similar system in reverse, where the engine turns a turbine that compresses air for thrust. Modern windmills also use turbines to generate electricity.
Parsons created Newcastle and District Electric Lighting Company, an early power company (established 1889, about seven years after Edison’s New York power plant) and the first to use turbines to spin generators. Parson’s turbine company still exists as a division of Siemens.
Gutaf de Laval created a different type of turbine to accelerate a stream.