Power plants are large facilities that have the equipment needed to produce or generate electricity. Due to its massive size it generally takes about 1,300 employees to safely and effectively run daily operations.
These types of plants can go by several different names including,
- Generating station
- Power station
- Generating Plant
These types of plants house one to many generators, which are basically machines that rotate in order to convert mechanical power into consumable energy. Many power plants in the United States use fossil fuels like natural gas and coal to generate energy, while others use nuclear power. Currently, there is a growing demand for power plants to use more renewable sources such as wind, and solar. It is possible for a power plant to have a generator that uses more than 1 kind of fuel.
History of Power Plants
Power plants are not a recent invention. The earliest example comes all the way from England, around the mid 1800s. A man by the name of Lord Armstrong designed and built his own power plant. It took water from several lakes on his property to generate power for lights, hot water, an elevator and other farm buildings and equipment.
One of the first public power plants was constructed in Godalming, England. It used hydroelectric energy to generate power for streetlights as well as lights within residential homes. Unfortunately, this project did not appeal to the townspeople and eventually they turned back to gas as their primary source of energy.
It wasn?t until 1882 that the United States constructed their very first power plant. The Pearl Street Station was developed to provide electricity for lighting in the area of lower Manhattan Island. This particular station used steam engine technology to turn its generators. It wasn?t very energy efficient, nor did it provide energy to widespread areas within America, but it did run until 1890 when it was destroyed in a fire.
During the last several years of the 1900s, central stations grew in size, and began to use different and improved technologies. Higher steam pressure was used more efficiently and also relied on the connection between multiple stations to decrease cost and increase reliability.
In America today, there are approximately 19,243 generators that can produce at least 1 megawatt in electric power, and around 7,304 operational power plants.
How Do Power Plants Work?
At its core, a power plant is simply a machine that removes energy from a particular fuel. This process requires several stages or steps, where unfortunately, some energy is wasted while some is consumed. These steps include,
Fuel ? This is what the power plant extracts energy from. Power plants can run on fuels like oil, natural gas, coal, or even methane gas.
Furnace ? The fuel is burned at high temperatures to release the energy. The energy is typically released as a heat.
Boiler ? In this stage, heat from the furnace moves around pipes filled with cold water. The heat energy boils that cold water to create steam.
Turbine ? The steam moves around a wheel consisting of many metal blades all packed tightly together. This movement spins the blades and generates kinetic energy, which is defined as energy that is created by something that moves. In order for this to work, the heat has to enter these metal blades at extremely high pressure and temperature and exit at a low pressure and temperature.
There are several different types of turbines. They include,
- Steam Turbine ? This is the most commonly used machine. It relies on steam generated from burning different kinds of fuel in order to work.
- Gas Turbine ? This turbine uses the pressure built by moving gas. These types of turbines start really fast and are therefore primarily used to supply electricity during times of peak demand.
- Reciprocating Engines ? These types of turbines are usually reserved for providing electricity to rural or remote areas. Offices, hospitals, and other critical industry buildings also use these turbines to generate backup power in emergency situations.
Cooling Tower ? Cooling towers are typically shaped like giant jugs. The hot water from the turbines are cooled down and then sprayed into the tower. At this point, the water is then reused.
Generator ? Connected to the turbine is a generator. This means that when the turbines spin, the generators also spin. To produce electricity, the generators use the kinetic energy generated by the turbine.
Cables ? Once the energy is produced, it will travel up these electricity cables and into a nearby transformer. From here, the electricity moves through a few more steps to get where it needs to go (homes, office buildings, etc.).
In general, today?s power plants use a combination of heat and power, and even capture more heat in order to generate electricity more efficiently.
Different Types of Power Plants
Most power plants are considered to be Thermal Power Plants. This is because they all use thermal energy (heat) from a fuel source (coal for example) and turn it into kinetic energy. That being said, power plants are still typically classified or defined by heat source and include,
Fossil Fuel Power Stations
Coal is one of the most commonly used fossil fuels used to generate electricity in a fossil fuel power station. These plants can use either a steam or combustion turbine. The coal is burned in a boiler at high temperatures. The steam produced moves a turbine, which then moves the generator to produce energy.
Nuclear Power Plants
These types of power plants use the heat from a nuclear reactor. This means that instead of using fossil fuels, nuclear power plants use radioactive elements like, uranium and thorium. A nuclear reactor and heat exchanger tubes also replace the furnace and boiler.
Instead of burning fuel, the uranium or thorium is put through a process that creates a fission reaction. This reaction produces the required heat needed to generate steam, which then moves the turbine and generator to create electricity. The United States produces about 20% of its electricity from these types of plants.
Renewable Energy Power Plants
Power plants can also use renewable energy to generate electricity. These forms of ?fuel? include,
- Pumped Storage
Geothermal Power Plants
Geothermal power plants take advantage of the steam generated by naturally heated rocks underground. The steam is used in the same way as other power plants ? to turn a turbine and generator. This technology is used in 24 countries, 28% of which is implemented in the United States. This type of power generation is renewable because it does not use more heat than the Earth is capable of producing.
Biomass-Fueled Power Plants
This power plant uses waste from different sources like sugar cane or landfill methane to produce steam.
Solar Thermal Plants
These types of plants use the heat from the sun to boil water and generate steam. The steam also moves a turbine, which then moves the generator to produce electricity.
Power plants also serve many different purposes. For example, a Peaking Power Plant?s job is to meet the daily peak energy load. This load could only be for two hours every day, but they ensure that the system or grid runs smoothly at all times. It is critical for these types of plants to start up and generate power quickly, which is why they mostly use gas turbines.
Major Power Plants in the United States
While there are many power plants all over the world, the United States has some of the largest. They produce much of the electricity the country consumes every year. The top ten power plants (as of 2015) include,
Palo Verde (Arizona)
Browns Ferry Nuclear Station (Alabama)
Oconee Nuclear Generating Station (South Carolina)
South Texas Project Nuclear Station (Texas)
Grand Coulee Hydroelectric Station (Washington, D.C.)
Braidwood Nuclear Station (Illinois)
West County Energy Center (Florida)
Byron Nuclear Generating Station (Illinois)
Limerick Nuclear Generating Station (Pennsylvania)
Scherer Coal-Fired Power Plant (Georgia)