Energy Generation 101
Overview of today’s generation resources
The electric grid in the United States is powered by a diverse mix of energy generation resources. These fall into three primary categories: fossil fuels, nuclear energy and renewable energy. While each plays a significant role in powering the country, fossil fuels and nuclear are responsible for more than 78 percent of the electricity generated in the United States.
| Fossil Fules | 60% | |
| Nuclear | 18.6% | |
| Renewables | 21.4% |
*Renewables include wind, hydropower, solar, biomass and geothermal combined.
Based on data from Electric Power Monthly, February 2024.
A closer look at fossil fuels, nuclear power and renewable energy
Fossil fuels:
Fossil fuel sources include coal, natural gas and petroleum. These have historically been the dominant energy sources and they continue to lead the way today. Currently, the two leading fossil fuels for energy generation are natural gas and coal.
Natural gas is the leading single source of electricity generation. Approximately 43 percent of America’s electricity comes from natural gas. Its strengths are abundance, relatively low cost and lower carbon emissions compared to coal.
Coal is a reliable and cost-efficient energy source. Unfortunately, EPA regulations have made coal plants too costly to operate, reducing its use. However, coal still contributes significantly to the grid in certain regions.
Nuclear energy:
Nuclear accounts for approximately 18% percent of electricity generation. Nuclear provides a stable, low-carbon energy source. Despite high initial costs and public concern over safety and waste disposal, nuclear power remains a key part of the energy mix due to its reliability and low greenhouse gas emissions.
Renewable energy:
The word “renewable” refers to energy from sources that are not depleted when used. Renewable energy includes wind, solar, hydroelectric, geothermal and biomass, and they have all seen rapid growth in recent years.
Wind energy is the leading source of renewable electricity, providing around 10% of the nation’s power, followed by solar power, which contributes around 4%. PowerSouth’s fleet does not use wind because it requires a sustained wind that is not common in our region. It is more suitable for open areas like the Midwest.
Solar energy, both utility-scale and distributed (such as rooftop solar), has expanded significantly due to declining costs and supportive policies. PowerSouth purchases 80 megawatts of carbon-free solar energy from a utility-scale solar facility in Wing, Alabama. The facility occupies more than 900 acres. Click here to monitor its generation in real time.
Hydroelectric power is one of the oldest sources and continues to be a major contributor, particularly in the Pacific Northwest. Here at home, PowerSouth’s Gantt & Point A dams have operated as green sources of energy for nearly a century.
Other sources including geothermal and biomass provide smaller but important shares of energy. Electricity generated at the Springhill Regional Landfill near Campbellton, Florida, is added to PowerSouth’s generation mix through a partnership between Waste Management and PowerSouth. To make electricity, methane gas from the landfill is extracted and burned, generating 4.8 megawatts of green energy.
Interested in renewable energy?
Click here to learn more about PowerSouth’s renewable energy sources or make a commitment to Green Power through your local cooperative.
If you’re considering rooftop solar panels, get all the facts.
Talk to the experts at your local electric cooperative.
Glossary of Terms
| Baseload Plant | Baseload means the minimum level of demand on an electrical grid over a specific period of time. These power plants are slow to start. But once running, they can provide steady, extended power at a low cost. Some nuclear and coal power plants fall into this category. |
| Capacity Factor | This is a percentage that measures how often a power plant is operating at maximum power, or the amount of energy it produces as compared to its maximum output. |
| Dispatchable Resources | This refers to generation resources that are available to produce power as needed, regardless of wind, sun or water supply. Dispatchable generation facilities, including nuclear, coal and natural gas plants, carry the heaviest load in providing affordable, reliable energy. |
| Energy/Capacity | Wholesale energy is measured in megawatt hours (MWh), while retail energy is measured in kilowatt hours (kWh). Capacity, measured in megawatts (MW), represents the potential energy production at a given moment. |
| Electric Cooperative | A not-for-profit, member-owned utility company created to deliver affordable energy to its member-owners. Electric cooperatives are democratically governed and focused on improving lives in the communities they serve. |
| Fossil Fuels | Fossil fuels are natural fuel sources formed from the decomposed remains of plants and animals that lived long ago. The three main fossil fuels are coal, oil and natural gas. |
| Generation/Transmission/Distribution | There are three key stages in the delivery of electricity: generation, transmission and distribution. Power plants generate electricity, which is then transported via high-voltage transmission lines over long distances. Substations use transformers to adjust the voltage for safe use in homes and businesses, where lower voltages are necessary. Distribution lines carry this electricity to end users. |
| Green Power Choice | A voluntary program, Green Power Choice allows consumers/members to purchase renewable energy from their local electric cooperative. |
| Intermittent Resources | These are weather-dependent resources (like solar and wind) that only generate energy when the sun is shining or the wind is blowing. These stand in contrast to Dispatchable Resources that can generate electricity at any time, regardless of weather. |
| Load Curtailment (Blackouts) | When electric demand is extremely high and there is not enough available generation, load curtailments, or “blackouts,” can be implemented to protect the electric grid from collapsing and to keep power flowing to as many members as possible. A curtailment is a controlled, temporary reduction of power. It is a last-resort measure to safeguard the electric grid. |
| Peaking Plant | Some power plants are referred to as “peaking plants.” These are power plants that only run when there is exceptionally high demand (“peak demand”) for electricity. Peaking plants operate in combination with baseload plants, which supply a consistent, reliable amount of electricity to meet the typical minimum demand. |
| PowerSouth Energy Cooperative | PowerSouth is a generation and transmission (G&T) electric cooperative that provides wholesale power to 16 electric cooperatives and four municipal electric systems in Alabama and northwest Florida. |
| Staying Power | A public information campaign designed to keep electric consumers informed on issues that could impede the delivery of reliable, affordable electric power. |
| Renewable Energy | Energy from sources that are not depleted when used, such as wind, solar and hydroelectric power. |