Last updated on: 10/2/2023 | Author: ProCon.org

Alternative Energy Sources Explained

In 2022, renewable energy accounted for 8.09% of U.S. energy consumption and nuclear energy accounted for 8.05%. Below find three pros and three cons and background information for each type of alternative energy.


Biomass

PRO

  • Renewable energy
  • Waste reduction
  • Reliability

CON

  • High costs
  • Space requirements
  • Environmental impact

Biomass accounted for

4.83%

of total US energy consumption in 2022


According to the US Energy Information Administration, “Biomass is renewable organic material that comes from plants and animals. Biomass was the largest source of total annual U.S. energy consumption until the mid-1800s… Biomass contains stored chemical energy from the sun. Plants produce biomass through photosynthesis. Biomass can be burned directly for heat or converted to renewable liquid and gaseous fuels through various processes.

Biomass sources for energy include

  • wood and wood processing wastes—firewood, wood pellets, and wood chips, lumber and furniture mill sawdust and waste, and black liquor from pulp and paper mills
  • Agricultural crops and waste materials—corn, soybeans, sugar cane, switchgrass, woody plants, and algae, and crop and food processing residues
  • Biogenic materials in municipal solid waste—paper, cotton, and wool products, and food, yard, and wood wastes
  • Animal manure and human sewage.

Biomass is converted to energy through various processes, including

  • Direct combustion (burning) to produce heat
  • Thermochemical conversion to produce solid, gaseous, and liquid fuels
  • Chemical conversion to produce liquid fuels
  • Biological conversion to produce liquid and gaseous fuels.”

Sources:

Energy Sage, “Biomass Pros and Cons,” energysage.com, Dec. 24, 2019
U.S. Energy Information Administration, “Biomass Explained,” eia.gov, Aug. 28, 2020
U.S. Energy Information Administration, “Primary Energy Consumption by Source,” eia.gov (accessed Sep. 28. 2023)

Geothermal

PRO

  • Reliable
  • Small land footprint
  • Works for large and small scale installations

CON

  • Location dependent
  • High initial costs
  • Can lead to earth surface instability

Geothermal accounted for

0.12%

of total US energy consumption in 2022


According to the US Energy Information Administration, “Geothermal energy is heat within the earth. The word geothermal comes from the Greek words geo (earth) and therme (heat). Geothermal energy is a renewable energy source because heat is continuously produced inside the earth. People use geothermal heat for bathing, to heat buildings, and to generate electricity.” The USEIA continues, “Geothermal reservoirs are naturally occurring areas of hydrothermal resources. These reservoirs are deep underground and are largely undetectable above ground. Geothermal energy finds its way to the earth’s surface in three ways: Volcanoes and fumaroles (holes in the earth where volcanic gases are released) Hot springs Geysers.”


Sources:

Energy Sage, “Geothermal Energy Pros and Cons,” energysage.com, Sep. 27, 2019
U.S. Energy Information Administration, “Geothermal Explained,” eia.gov, Dec. 5, 2019
U.S. Energy Information Administration, “Primary Energy Consumption by Source,” eia.gov (accessed Sep. 28. 2023)

Hydroelectric

PRO

  • Renewable energy
  • Pairs well with other renewable energies
  • Meets peak electricity demands

CON

  • Environmental impact
  • High initial costs
  • Lack of available reservoirs

Hydropower accounted for

0.89%

of total US energy consumption in 2022


According to the US Energy Information Administration, “People have a long history of using the force of water flowing in streams and rivers to produce mechanical energy. Hydropower was one of the first sources of energy used for electricity generation and and until 2019, hydropower was the largest source of total annual U.S. renewable electricity generation…

Because the source of hydroelectric power is water, hydroelectric power plants are usually located on or near a water source. The volume of the water flow and the change in elevation—or fall, and often referred to as head—from one point to another determine the amount of available energy in moving water. In general, the greater the water flow and the higher the head, the more electricity a hydropower plant can produce.

At hydropower plants water flows through a pipe, or penstock, then pushes against and turns blades in a turbine to spin a generator to produce electricity.”


Sources:

Energy Sage, “Hydropower Pros and Cons,” energysage.com, Dec. 24, 2019
U.S. Energy Information Administration, “Hydropower Explained,” eia.gov, Mar. 30, 2020
U.S. Energy Information Administration, “Primary Energy Consumption by Source,” eia.gov (accessed Sep. 28. 2023)

Nuclear

PRO

  • Low carbon
  • Not weather dependent
  • Low running costs

CON

  • Nuclear meltdowns
  • Nuclear waste
  • High building costs

Nuclear accounted for

8.05%

of total US energy consumption in 2022


According to the US Energy Information Administration, “In nuclear fission, atoms are split apart, which releases energy. All nuclear power plants use nuclear fission, and most nuclear power plants use uranium atoms. During nuclear fission, a neutron collides with a uranium atom and splits it, releasing a large amount of energy in the form of heat and radiation. More neutrons are also released when a uranium atom splits. These neutrons continue to collide with other uranium atoms, and the process repeats itself over and over again. This process is called a nuclear chain reaction. This reaction is controlled in nuclear power plant reactors to produce a desired amount of heat. Nuclear energy can also be released in nuclear fusion, where atoms are combined or fused together to form a larger atom. Fusion is the source of energy in the sun and stars.”


Sources:

U.S. Energy Information Administration, “Nuclear Explained,” eia.gov, Apr. 17, 2020
U.S. Energy Information Administration, “Primary Energy Consumption by Source,” eia.gov (accessed Sep. 28. 2023)
Jack Unwin, “Nuclear Power: The Pros and Cons of the Energy Source,” power-technology.com, June 18, 2020

Solar

PRO

  • Renewable energy
  • Diverse applications
  • Low maintenance costs

CON

  • High initial costs
  • Weather dependent
  • Large footprint

Solar accounted for

0.76%

of total US energy consumption in 2022


According to the US Energy Information Administration, “The sun has produced energy for billions of years and is the ultimate source for all of the energy sources and fuels that we use today. People have used the sun’s rays (solar radiation) for thousands of years for warmth and to dry meat, fruit, and grains. Over time, people developed technologies to collect solar energy for heat and to convert it into electricity…

Solar photovoltaic (PV) devices, or solar cells, change sunlight directly into electricity. Small PV cells can power calculators, watches, and other small electronic devices. Arrangements of many solar cells in PV panels and arrangements of multiple PV panels in PV arrays can produce electricity for an entire house. Some PV power plants have large arrays that cover many acres to produce electricity for thousands of homes.”


Sources:

Aris Vourvoulias, “Pros and Cons of Solar Energy,” greenmatch.co.uk, July 7, 2020
U.S. Energy Information Administration, “Primary Energy Consumption by Source,” eia.gov, July 2020
U.S. Energy Information Administration, “Primary Energy Consumption by Source,” eia.gov (accessed Sep. 28. 2023)

Wind

PRO

  • Renewable energy
  • Low operating costs
  • Efficient use of land

CON

  • Weather dependent
  • Noise and visual pollution
  • Environmental impact

Solar accounted for

1.48%

of total US energy consumption in 2022


According to the US Energy Information Administration, ” Wind is caused by uneven heating of the earth’s surface by the sun. Because the earth’s surface is made up of different types of land and water, it absorbs the sun’s heat at different rates. One example of this uneven heating is the daily wind cycle.” The USEIA continued, “Wind turbines use blades to collect the wind’s kinetic energy. Wind flows over the blades creating lift (similar to the effect on airplane wings), which causes the blades to turn. The blades are connected to a drive shaft that turns an electric generator, which produces (generates) electricity.”


Sources:

Energy Sage, “Wind Energy Pros and Cons,” energysage.com, Sep. 27, 2019
U.S. Energy Information Administration, “Primary Energy Consumption by Source,” eia.gov (accessed Sep. 28. 2023)
U.S. Energy Information Administration, “Wind Explained,” eia.gov, Dec. 4, 2019