Understanding the Basics
Energy is fundamental to modern life — it powers our homes, fuels transportation and drives the technologies we rely on every day. It is a simple fact: we need energy to survive and function. Yet the concept of energy can be quite complicated. This brief introduction provides a foundational understanding of energy and its importance.
Energy and Electricity
It’s important to know that energy and electricity are not the same. In the simplest terms, energy is the capability to do work — it is the power that allows people, animals and machines to move and do things. Our bodies use energy from food to function, plants use energy from the sun to grow and cars use energy from fuel to drive. Natural resources, for example, contain the energy that we rely on to power devices and machinery. Energy is fuel like gasoline or propane, geothermal power, wind that blows through turbines, and coal or gas that can be burned to emit heat. Electricity is a specific and widely used form of energy which we use to power our devices, light our homes and run appliances. Electricity allows us to send energy over vast distances in the blink of an eye. Modern communications, technology, medical advancements and industry would be nearly impossible without electricity.
How Electricity Gets to You
Electricity doesn’t just appear at the wall outlet. It is generated at power plants, often far from where it’s used. Once generated, it travels through a complex transmission and distribution network called the electrical grid. The electrical grid is an intricate network of wires that consists of power stations, substations, transmission lines and the distribution poles you see outside your house and in your neighborhood. The grid is what delivers electricity from power plants to homes, businesses and industries.
Types of Energy Sources and How They are Produced
Electricity can be generated from a variety of energy sources at power plants. Power plants convert these energy sources into electricity in a variety of ways:
- Coal – Coal plants burn coal in massive boilers to generate electricity. Some coal plants can burn other fuels in addition to coal.
- Natural Gas – Natural gas plants burn the fuel and use the expanding exhaust gas to turn a turbine and generate electricity. The hot exhaust can then be used to create steam and turn another turbine.
- Nuclear – Nuclear plants use the decomposition of radioactive elements that heat water and turn it into steam to generate electricity.
- Wind – Wind turbines take advantage of natural air patterns, using the wind to spin the rotors that generate electricity.
- Solar – There is utility-scale solar and residential-scale solar. Each works to convert the sun’s energy into electricity, but utility-scale solar can rival the size of other power plants. In Missouri, three-fourths of our solar energy comes from residential solar.
- Hydroelectric – Massive dams strategically release huge reservoirs of water to generate energy. Excess energy from other sources can also be used to pump water into these reservoirs to store energy for later use.
- Biomass – Biomass facilities burn waste products from the agriculture, forestry and construction industries to generate electricity.
- Petroleum – Similar to coal plants, petroleum fuel plants burn a liquid fossil fuel in a boiler to generate electricity.
Energy in Missouri
Missouri relies on a variety of energy sources. Below is Missouri’s in-state electricity generation, by source, as of 2023, according to the U.S. Energy Information Administration (EIA):
- Coal – 60%
- Nuclear – 13.67%
- Natural Gas – 13.55%
- Wind – 10.14%
- Hydroelectric – 2.05%
- Utility-Scale Solar – 0.26%
- Biomass – 0.16%
- Petroleum – 0.14%
For more information on electricity in Missouri, visit EIA's Missouri State Profile and Energy Estimates web page.
The Role of Utilities
Utility companies are responsible for delivering electricity to homes and businesses through the electrical grid. Many utilities also generate their own electricity to distribute to consumers. These utilities are called vertically integrated utilities and are responsible for the entire process, from generation to transmission to distribution.
Utilities play a critical role in maintaining grid reliability, investing in infrastructure and ensuring regulatory compliance. Utilities can be privately-owned companies (called investor-owned utilities), public agencies run through the local municipal government, or member-owned cooperatives. In Missouri, there are five investor-owned companies, over 120 municipal utilities, and 40 distribution cooperatives.
The Missouri Public Service Commission (PSC) regulates all the investor-owned utilities that provide electric, natural gas, telecommunications, water and sewer service to households and businesses in the state. The PSC ensures that these companies deliver services promptly, safely and at a reasonable price.
Current Energy Challenges
The energy sector faces several pressing challenges, including modernizing aging infrastructure, securing grid reliability, ensuring equitable access to affordable energy, reducing carbon emissions and meeting increasing energy demands. Addressing these issues requires innovation, policy coordination and informed public engagement. The Division of Energy, along with other partner agencies, is uniquely positioned to help address these emerging issues. The upcoming Missouri Nuclear Summit is an opportunity for energy experts and the public to come together to discuss pathways for overcoming certain energy challenges.
Understanding the Basics
Nuclear energy is a powerful and reliable source of energy that plays an important role in today’s global energy mix. As nuclear energy grows more popular, conversations about nuclear development continue across the world. This brief introduction provides a foundational understanding of nuclear energy as Missouri prepares for the upcoming Missouri Nuclear Summit.
What is Nuclear Energy?
Nuclear fission is the process by which nuclear energy is harnessed. Fission occurs when the nucleus of an atom splits into two or more parts. The atom that is used in this process is Uranium-235, a radioactive isotope. Uranium-235 makes up only of 1% of all naturally occurring Uranium, but its radioactivity is necessary for nuclear energy production, as it easily breaks apart when struck by a neutron. When the radioactive Uranium-235 atom is split, large amounts of energy are released in the form of heat. At the same time, the nucleus releases neutrons, and the ejected neutrons hit surrounding atoms, which then split to hit more atoms. The multiplying effect generates a chain nuclear reaction that allows us to generate consistent energy in a nuclear plant.
How Nuclear Power Works
In a nuclear power plant, rods containing uranium are placed in a reactor where fission occurs. The generated heat warms the reactor’s cooling agent, which is typically water, to produce steam. This steam is then channeled to spin turbines, activating an electric generator to create low-carbon electricity.
Benefits of Nuclear Energy
Nuclear energy is a low-carbon energy source. Nuclear energy is released through a procedure called nuclear fission — a process that doesn’t release greenhouse gasses like carbon dioxide during its operation. Although mining, processing and storing waste for nuclear energy produces some emissions, it is still significantly lower than burning fossil fuels.
Nuclear energy is stable and reliable. Nuclear energy is produced in generating power plants — much like gas and coal power plants — that can operate around the clock. These energy sources are not dependent on wind, sun or rainfall to produce electricity. Although it may take 12 hours or more for a nuclear plant to reach full operational capacity, it can be shut down within seconds.
Nuclear energy is powerful and efficient and nuclear fuel is very energy dense. For example, a single uranium fuel pellet — about the size of a pencil eraser — contains as much energy as one ton of coal, 149 gallons of oil, or 17,000 cubic feet of natural gas. And because fission is nearly 8,000 times more efficient than traditional fossil fuels, less fuel is required to power the plant and less waste is produced.
Nuclear – Your Questions Answered
Is it safe to live next to a nuclear power plant?
Yes. The federal Nuclear Regulatory Commission oversees the safety of the country’s nuclear reactors, including the reactor in Callaway County, Missouri. Reactors in the United States have numerous safety features and are hardened against natural disasters and human intrusion. Although nuclear accidents have occurred in the past, they have been extremely rare around the world. Nuclear generation continues to grow safer as technology and safety efforts increase.
How much nuclear power is produced in Missouri?
There is one nuclear power plant in Missouri. Ameren Missouri’s Callaway Energy Center produced over 14% of the electricity made in Missouri in 2024, and its output is enough to power 780,000 average households.
How is nuclear waste disposed of?
The Callaway Energy Center, Missouri’s only nuclear power plant, stores “high-level” nuclear waste and “low-level” nuclear waste differently. High-level nuclear waste is radioactive nuclear fuel that has been removed from the nuclear reactor and contained in fuel rods. These rods are temporarily stored in a spent fuel pool, a stainless steel-lined water pool the size of a tennis court where the radioactive fuel will lose 90% of its radioactivity in the first year of storage. After the fuel has cooled, the spent fuel is then moved to concrete-and-steel containers called dry casks. These are sturdy structures that are built to survive natural disasters, human intrusion and other unusual scenarios.
Low-level radioactive waste includes disposable items such as protective clothing, filters and tools that have become contaminated in working with radioactive material. Ninety-five percent of low-level waste is Type A, which has the lowest amount of radioactivity, and is shipped to a disposal facility in Utah. The other five percent is stored on-site. Low-level disposal sites continue to advance as hospitals, research laboratories, nuclear plants and manufacturing facilities seek safe, low-level waste disposal.
Learn more about nuclear waste disposal by reading Ameren Missouri's Callaway Plant Environmental Facts sheet.
Can nuclear materials be used in medicine?
Yes. Certain nuclear products can be used for diagnosis and imaging, radiotherapy and medical equipment sterilization. The University of Missouri Research Reactor (MURR®) is one of the most powerful university research reactors in the United States and a major source of medical nuclear products.
What are the environmental impacts of nuclear power?
Conventional nuclear power plants produce little carbon emissions during their operation. They do, however, require water for operations and cooling. Most of the water that meets the radioactive elements is in a closed-cycle and will never be released to the environment. Thermal pollution, however, is the discharged heated water which poses the largest environmental concern. This is similar to any other power plant that uses water as a cooling agent. Most of nuclear energy’s emissions come from mining and refining uranium. Nuclear reactors also produce radioactive waste from their operations; however, nuclear power plants emit less radiation into the surrounding environment than coal-fired power plants.
Nuclear Around the World
The United States leads the world in nuclear energy consumption. China, France, Russia and South Korea are also major nuclear consumers and producers of nuclear energy. Globally, over 30 countries operate nuclear power plants.
With nuclear innovation expanding, many new reactor designs are under consideration around the world. Some of these new designs could allow for smaller, standardized reactors with improved safety features.
Current Nuclear Construction Plans in Missouri
Ameren Missouri recently announced plans to add 1,500 MW of new nuclear generation by 2040. The company also expects to seek an extension of the operating license for its Callaway nuclear plant beyond 2044. The University of Missouri plans to construct a new reactor that will have twice the power of its current facility, although it will not be used for power generation.
Elsewhere in the United States, there is an increased interest in nuclear power to meet growing electricity demand safely and reliably. Executive Orders Unleashing American Energy and Declaring a National Energy Emergency both promote domestic energy production and nuclear resource development, sparking nuclear conversations across the nation.
Aside from Missouri, other states are participating in the nuclear arena. In Georgia, Plant Vogtle is expanding to include two new nuclear units, making the plant the largest nuclear energy generator in the country. Tennessee is also advancing multiple nuclear power plant projects, including a potential small modular reactor development at the Clinch River Nuclear site. Crane Clean Energy Center in Pennsylvania is being restored and is expected to be back online by 2028.
