“Non-renewable” energy sources (such as Oil and Petroleum Products, Natural Gas, Natural Gas Liquid, Coal, and Nuclear), as well as “renewable” energy and “alternative fuels” (such as Hydro, Solar, Wind, Geothermal, Biomass, and Biofuels), help to satisfy the nation’s energy needs. Fossil fuels and nuclear power are considered non-renewable sources of energy. Coal and natural gas play large roles in the generation of electricity as well as in industrial processes such as the manufacturing of steel. Hydro, solar, wind, biomass, biofuels, and geothermal are all considered “renewable” forms of energy and comprise varying levels of supply in this country. They are classified as renewables since their source is considered to be virtually unlimited. Of these, solar, wind, biomass, biodiesel, and geothermal are all considered “alternative” energy sources since they are not the “traditional” kind (fossil fuels, nuclear, and hydro).
The following chart is from EIA reported data and shows major energy sources and percent shares of U.S. electricity generation at utility-scale facilities in 2023. Please note that in 2023, natural gas had the largest share (43.1%) in U.S. electricity generation, renewables were in the second place (21.4%), and nuclear had the third place (18.6%). As shown in Figure 1, renewable energy sources contribute to about 21% of the U.S. electricity production at utility-scale facilities as of 2023, with about 10.2% wind power, 5.7% hydro, and 3.9% solar. Other renewable sources, such as biomass and geothermal, have a minor share.
Text description of the Sources of U.S. Electricity Generation image.
This image is a simple vertical stacked bar graphic showing the sources of U.S. electricity generation in 2023, with percentages for each energy source.
The main visual element is a single tall rounded rectangle centered on the page. It is divided into four horizontal colored sections, stacked from bottom to top like layers in a column.
- The bottom and largest section is light gray and labeled “natural gas 43.1%.” This section takes up nearly half of the total height.
- Above it is a smaller tan section labeled “coal 16.2%.”
- Above that is a light blue section labeled “nuclear 18.6%.”
- The top section is green and labeled “renewables 21.4%.”
Together, these four stacked sections fill the entire vertical bar, representing nearly all electricity generation.
To the right of the bar, a small label points to a very thin portion at the top edge and reads “petroleum and other 0.8%,” indicating a very small contribution not visually prominent in the main stack.
To the left of the bar, there is a small box listing the breakdown of the renewable category:
- wind: 10.2%
- hydro: 5.7%
- solar: 3.9%
- biomass: 1.1%
- geothermal: 0.4%
At the top of the image, the title reads “Sources of U.S. electricity generation, 2023,” with a subtitle stating a total of 4.18 trillion kilowatthours.
At the bottom, the data source is listed as:
“Data source: U.S. Energy Information Administration, Electric Power Monthly, February 2024, preliminary data.”
The note at the bottom reads:
“Note: Includes electricity generated from power plants with at least 1,000 kilowatts of electric generation capacity (utility-scale). Hydro is conventional hydroelectric. Petroleum and other includes petroleum liquids and petroleum coke, other gases (blast furnace gas and other manufactured and waste gases derived from fossil fuels), hydroelectric pumped storage, and other sources (non-biogenic municipal solid waste, batteries, hydrogen, purchased steam, sulfur, tire-derived fuel, and other miscellaneous energy sources). Sum of percentages may not equal 100% because of independent rounding.”
Figure 2 below shows the breakdown of fuel sources used in the generation of electricity throughout history. As you can see, the single largest fuel had been coal until around 2015. After that, natural gas took the top place, and continued to expand. The shift, or "fuel switching," was driven by increased domestic gas production, environmental regulation (natural gas is "cleaner" than coal), and relatively low gas prices during 2010-2020. The contribution from nuclear remained largely stable, while renewables also experienced a rapid expansion since 2010.
Text description of the U.S. electricity generation by major energy source image. XXXXXXXXXXXXX
The image is a wide, horizontal stacked area chart with a white background. The chart is filled with layered colored bands that stretch from left to right across the page, representing different energy sources over time.
The bottom layer is a large brown band representing coal, which starts relatively thin on the left side (around 1950), grows thicker toward the middle of the chart, and then narrows again toward the right side (recent years). Above it is a blue band for natural gas, which begins thin but steadily thickens, becoming one of the largest layers on the right side.
Above the blue layer is a red band representing nuclear energy. This band appears suddenly around the 1970s, grows quickly, and then maintains a fairly consistent thickness across the rest of the chart.
Above that is a green band for renewables, which starts very thin and gradually becomes thicker toward the far right, especially in recent years.
At the very top is a tan-colored band for petroleum and other sources, which is more noticeable in the earlier decades but becomes very thin and nearly disappears toward the right side.
All of these colored layers are stacked on top of each other, so the total height of the combined layers shows total electricity generation. The overall shape rises from left to right, forming a broad hill that peaks around the mid-to-late 2000s, then flattens with slight dips and rises toward the present.
The horizontal axis along the bottom shows years from 1950 to 2023, while the vertical axis on the left shows increasing values up to about 4,500 billion kilowatthours. A legend with colored boxes appears below the chart, matching each color to its energy source.
Overall, the chart looks like a layered landscape of colored bands, with some layers shrinking and others expanding over time, visually showing shifts in energy use.
Five energy sources are shown as colored layers stacked on top of each other:
- Coal (brown, bottom layer)
- Natural gas (blue)
- Nuclear (red)
- Renewables (green)
- Petroleum and other (tan, top layer)
Overall Trend
Total electricity generation increases steadily from 1950 through the mid-2000s, reaching over 4,000 billion kilowatthours, and then remains relatively stable with small fluctuations through 2023. Exact values for each year are not given but show the overall trend. To see the exact values go to US Electricity Generation by Source by U.S. Energy Information Administration to see the interactive version of this chart.
By Energy Source
- Coal dominates electricity generation from 1950 through the mid-2000s, steadily increasing and peaking around the late 2000s. After that, coal declines sharply, especially after 2010.
- Natural gas grows gradually through the late 20th century, then increases rapidly after about 2005. By the 2010s and 2020s, it becomes one of the largest sources of electricity.
- Nuclear energy rises quickly from about 1970 to the 1990s, then levels off and remains relatively constant.
- Renewables (including sources like wind and solar) remain small for much of the timeline but increase steadily after 2000, with faster growth in the 2010s and 2020s.
- Petroleum and other sources increase slightly in the mid-20th century but decline significantly after the 1970s and remain a small portion of total generation.
Key Pattern
The chart shows a major transition in U.S. electricity generation:
- Early reliance on coal
- Growth of nuclear power in the late 20th century
- A shift toward natural gas in the 21st century
- Increasing contribution from renewable energy
- Decline of coal and petroleum over time
At the bottom, the data source is listed as the U.S. Energy Information Administration, based on Monthly Energy Review and Electric Power Monthly data, with preliminary data for 2023.
Figure 3, below, displays the renewable energy sources that contribute to power generation. As you can see, there has been a rapid increase in wind and solar power generation. However, it will take decades for alternative fuels to make a substantial contribution to the energy portfolio in the United States. Thus, there is a need to continue to use fossil fuels and nuclear power to “bridge” the gap. How the former (fossil fuels and nuclear power) are delivered to the market and how they are priced is the main focus of this course.
Text description of the Renewable electricity generation image.
This image is a wide, horizontal stacked area chart titled “U.S. electricity generation from renewable energy sources, 1950–2023.” It shows how different renewable energy sources contribute to total electricity generation over time.
The chart has a light gray background. The horizontal axis runs from 1950 on the left to 2023 on the right. The vertical axis on the left shows values from 0 up to about 1,000 billion kilowatthours.
The data are displayed as layered colored bands stacked on top of one another, forming a continuous shape that rises and changes over time.
- The bottom and largest layer is blue, representing hydroelectric power. It starts around 100 billion kilowatthours in 1950, gradually increases, and fluctuates over time, forming a broad, uneven base across the entire chart.
- Above the blue layer is a thin brown band representing biomass. This band appears around the 1980s and remains relatively narrow, with slight increases over time.
- Above biomass is a thin orange band representing geothermal energy. This layer appears around the 1980s and stays small and fairly consistent in thickness.
- Above geothermal is a green band representing wind energy. This layer is nearly absent until about the early 2000s, then grows rapidly, especially after 2010, becoming one of the largest layers by the right side of the chart.
- At the very top is a yellow band representing solar energy. This layer is not visible until around 2010, then increases quickly, especially in the final years, forming a noticeable but still smaller top layer.
The overall shape of the stacked areas starts low on the left, rises gradually through the mid-20th century, and then increases more sharply after about 2005. The total height grows most rapidly in the 2010s and early 2020s, reaching close to 900 billion kilowatthours by 2023.
A legend below the chart matches each color to its energy source: solar (yellow), wind (green), geothermal (orange), biomass (brown), and hydroelectric (blue).
At the bottom, the data source is listed as the U.S. Energy Information Administration, based on Monthly Energy Review and Electric Power Monthly, with preliminary data for 2023. A note explains that the data include electricity generation from power plants with at least 1 megawatt of capacity and that hydroelectric refers to conventional hydropower.
Renewable electricity generation 1950 - 2023 (history):
Geothermal: Geothermal generation was relatively stable, and very low, from 1990 - 2023.
Biomass: Biomass generation has remained steady at about 50 - 60 billion kWh from 1990 - 2023.
Hydroelectric: Hydroelectric generation varied widely between about 220 billion kWh and 350 billion kWh from 1990 - 2023.
Utility-scale and end-use solar: Solar generated almost zero kWh before 2010. It rose from almost zero to about 165 billion kWh by 2023.
Wind: Wind power generated almost no power until 2004. From 2004 until 2023, it rose to about 425 billion kWh, more than 30 times of 2004 generation level.
Now that we have clarified the difference between renewable and non-renewable sources of energy from the electricity generation perspective, let’s take a look at the production and consumption of energy in the United States on a macro level.