Renewable and Nonrenewable Resources and Global Energy Consumption

Renewable and Nonrenewable Resources and Global Energy Consumption

Nonrenewable Energy Resources

• Definition: Nonrenewable energy resources are finite, meaning they cannot be replenished within a human timespan.

• Fossil Fuels: Derived from biological material that became fossilized millions of years ago, including:

  • Coal: Formed from plant material over millions of years.

  • Oil: Derived from marine organisms.

  • Natural Gas: Composed mainly of methane from decomposed organisms.

• Formation Process:

  • Fossil fuels form under anaerobic conditions where decomposers cannot break down biomass, leading to heat and pressure transformations of organic compounds.

• Contribution to Climate Change: Combustion of fossil fuels releases carbon dioxide stored for millions of years, significantly contributing to global climate change.

Nuclear Energy

• Nuclear Fuels: Derived from radioactive elements (like uranium ore) and also finite in supply.

Energy Measurement Units

• Joule (J): The basic energy unit (1 W-s).

• Gigajoule (GJ): 1 billion joules (~30 L gasoline).

• Exajoule (EJ): 1 billion gigajoules.

• Quad: Used by the U.S. government for energy consumption (1 quad = 1.055 EJ);

• Kilowatt-hour: For electrical energy.

Renewable Energy Resources

• Definition: Renewable energy resources are infinite and becoming more vital in global energy consumption.

• Categories of Renewable Resources:

  • Potentially Renewable: Can be replenished indefinitely if not overharvested (e.g., biomass, hydroelectric).

  • Nondepletable: Cannot be used up, regardless of consumption (e.g., solar, wind).

• Biomass Example: Essential for many developing regions, energy sources like wood and manure are often used but can lead to sustainability issues if overharvested.

Global Energy Consumption Trends

• Global Usage:

  • In 2020, total world energy consumption was approximately 600 EJ.

  • Fossil fuels (oil, coal, natural gas) constitute around 80% of total energy use.

  • Renewable energy accounts for about 15%, with hydroelectricity as the largest source of renewable energy.

Regional Energy Consumption Patterns

• Energy consumption globally is uneven, with developed countries using more fossil fuels compared to developing nations relying on biomass.

• Commercial Energy Sources: Bought and sold energy sources (coal, oil, natural gas).

• Subsistence Energy Sources: Local, non-commercial sources gathered for personal use (wood, dung).

Patterns of Energy Use in the United States

Historical Overview

• Energy Transition:

  • Wood was dominant until around 1875, followed by coal, oil, and natural gas.

  • Electricity from nuclear power grew in the 1960s.

  • Recent trends show a decline in coal usage and an increase in natural gas consumption.

Current Energy Mix

• U.S. energy consumption:

  • Approximately 100 EJ (or 95 quads) annually.

  • Composition: 79% fossil fuels, 9% nuclear, 12% renewable resources.

  • Renewables are now more significant than coal.

Energy Consumption by Region

• Varies with climate: warmer regions consume more electricity (for cooling) compared to northern areas (more oil and natural gas for heating).

• Examples:

  • Midwestern and Southeastern states primarily use coal.

  • Western and Northeastern states use a mix of nuclear, natural gas, and hydro.

Energy Supply and Sustainability

Finite Resources Assessment

• Ongoing evaluations by U.S. Geological Survey and others on fossil fuel reserves.

• Table 35.2: Provides estimated years of supply left for natural gas, oil, coal, and uranium ore in U.S. and worldwide.

  • Natural gas: 85 years (U.S.), 50 years (world).

  • Oil: 5 years (U.S.), 50 years (world).

  • Coal: 470 years (U.S.), 130 years (world).

  • Uranium ore: 20 years (U.S.), 130-200 years (world).

Energy Intensity and Efficiency

• Energy intensity: Measures energy use per unit of GDP, steadily decreasing in the U.S. over the past 50 years.

• Energy conservation and efficiency are crucial for sustainable energy use.

  • Conservation: Reducing energy consumption.

  • Efficiency: Ratio of useful energy output to energy input.

Future Energy Sources and Patterns

The Hubbert Curve

• Predicts when oil production will peak and eventually diminish.

• Suggested peak oil production might already have been reached or will soon be.

• Emphasizes the need to transition towards other energy sources due to environmental concerns from fossil fuels.

Transitioning to Renewables

• Exploring alternative energy sources and innovation in energy efficiency are key to sustainable energy.

• The focus is shifting from how much oil is left to what energy sources will replace fossil fuels.

• Energy Return on Energy Investment (EROEI): Measures the efficiency of energy production versus energy invested.

Conclusion

• Overview of renewable and nonrenewable resources and associated energy trends.

• Upcoming discussions will delve deeper into specific fuel types and their global distribution.