Electricity Generation Power Production

Electricity generation is a process that involves the production of electrical power through various sources. In the United States, power production from utility-scale generators was about 4.1 trillion kilowatt-hours (kWh) in 2019. Fossil fuels, including coal, natural gas, and petroleum, produced about 63% of the electricity, while nuclear energy produced around 20%. The remaining 17% was generated from renewable energy sources, including solar photovoltaics, wind turbines, and hydroelectric power production.

Hydroelectric power production units utilize flowing water to spin a turbine connected to a generator. Falling water systems accumulate water in reservoirs created by dams, which then release through conduits to apply pressure against the turbine blades to drive the generator. In a run-of-the-river system, the force of the river current applies pressure to the turbine blades to produce power. In 2000, hydroelectric generation had the fourth largest share (7 percent) of electricity production at 273 billion kWh.

Non-water renewable sources, including geothermal, refuse, waste heat, waste steam, solar thermal power plants, wind, and wood, contribute only small amounts (about 2 percent) to total power production. In 2019, power production from these sources totalled 84 billion kWh. The entire electric power industry production in 2019 was 3,800 billion kWh, with utilities net production accounting for 3,015 billion kWh and net generation by non-utility power producers 785 billion kWh.

The United States' share of electrical energy production from different sources has changed more rapidly since 2007 than ever since 1950. On the other hand, Canada's energy production is much less than the USA, mainly in Ontario and British Columbia. At least three trends are catalyzing these changes: (1) the low price of natural gas; (2) the rise in renewable and distributed generation due to falling costs; and (3) recent Federal and State policies impacting production.

Diversity is a key attribute in U.S. and Canadian electricity production. However, rather than being the result of a deliberative, long-term national initiative, this diversity has developed through growth spurts of specific production technologies at different times. This is often due to policies, historical events, capital costs, fuel costs, and technological advancements.

Most energy sources have experienced eras of significant capacity growth in terms of terawatt hours: hydro (1930‒1950, not shown); coal (1950-1985); nuclear (1960‒1980); natural gas (1990‒2010); and renewables (2005‒present).

The U.S. generation mix has transitioned over the past few decades and is projected to continue changing significantly. The U.S. generation fleet is transitioning from one dominated by centralized generators with high inertia and dispatchability to one more hybridized, relying on a mixture of traditional, centralized production and variable utility-scale and distributed renewable energy production.

To generate power, various sources are used, such as diesel engines, gas turbines, and nuclear power plants. Fossil fuels, including natural gas and coal, are burned to create hot gases that go through turbines, which spins the copper armature inside the generator and generate an electric current. In a nuclear power plant, nuclear reactions create heat to heat water, which turns into steam and goes through a turbine to produce electricity. In a wind turbine, the wind pushes against the turbine blades, causing the rotor to spin and generating an electric current. In a hydroelectric turbine, flowing or falling water pushes against the turbine blades, causing the rotor to spin and generating an electric current.

To meet these immediate demands, utilities and nonutility power producers operate several electric generating units powered by various fuel sources. Renewable fuels such as water, geothermal, wind, and other renewable energy sources like solar photovoltaics are used as sources of epower, besides fossil fuels and uranium.

Coal was the fuel used to generate the largest share (51.8 percent) of electricity in 2000, with natural gas and petroleum accounting for 16.1 percent and 3 percent, respectively. Steam-electric generating units burn fossil fuels such as coal, natural gas, and petroleum to produce steam, turning a turbine into a generator to produce power. On the other hand, gas turbine generators burn fuels to create hot gases, which also go through a turbine, spinning the copper armature inside the generator and generating an electric current. Diesel engine generators are also used, where the combustion occurs inside the engine's cylinders, which are connected to the generator's shaft. The mechanical energy provided by the turbine drives the generator to produce energy.

The production of electrical energy has experienced various eras of significant capacity growth in the United States, Canada, and other countries worldwide. The future of power production is transitioning to a more hybridized generation fleet that relies on a mixture of traditional, centralized production and variable utility-scale and distributed renewable energy production. This transition is driven by low natural gas prices, rising renewable and distributed generation, and recent Federal and State policies impacting generation.

How is electricity generated from renewable energy sources?

Electricity is generated from renewable energy sources by converting the energy of the sun, wind, water, or earth into electrical energy. For example, solar photovoltaic panels generate power directly from sunlight, wind turbines to generate electricity from wind energy, and hydroelectric power plants generate power from falling water.

What are the different types of fossil fuels used?

The different types of fossil fuels used include coal, natural gas, and petroleum. Coal is the most commonly used fossil fuel for energy production, followed by natural gas and oil.

What are the advantages and disadvantages of using nuclear power plants for electricity generation?

Advantages of using nuclear power plants include that they produce a large amount of energy with a low amount of fuel, emit less carbon dioxide than fossil fuel power plants, and are not dependent on weather conditions like wind or solar power. Disadvantages include the risks associated with nuclear accidents, the high cost of building and maintaining nuclear power plants, and the long-term storage of nuclear waste.

How do gas turbines work to generate electricity?

Gas turbines burn natural gas or other fuels to heat air, expanding and driving a turbine. Finally, the turbine is connected to a generator that converts the turbine's mechanical energy into electrical energy.

What is the role of steam turbines in electricity generation?

Steam turbines are commonly used to convert thermal energy from steam into mechanical energy that drives a generator. Steam is produced by burning fossil fuels or using heat from nuclear reactions or geothermal sources. The steam drives the turbine blades, which are connected to the generator to produce electricity.

What are some examples of non-renewable energy sources?

Examples of non-renewable energy sources used for power production include fossil fuels such as coal, natural gas, petroleum, and nuclear energy.

How is electricity generated and distributed in the United States?

Various power plants, including fossil fuels, nuclear energy, and renewable energy sources, generate electricity in the United States. Electric power is transported over a complex network of power lines and transformers to homes, businesses, and other consumers through local utility companies. The Federal Energy Regulatory Commission (FERC) and various state regulatory agencies regulate power distribution.