Global Energy Sources: History, Classification, and Key Types

The Evolution of Global Energy Sources

In the 18th century, wood was a key energy source.

Since the Industrial Revolution, people began to use coal, which became the main energy source in the 19th century, powering steam engines.

Electricity, oil, and gas were introduced in the late 19th century and remain crucial today.

Nuclear energy was discovered in the mid-20th century. New renewable energy sources like wind and solar gained popularity following the 1973 energy crisis.

Energy Classification Systems

Classification by Depletion Rate

• Renewable: Those which cannot be used up (e.g., solar, hydraulic).
• Non-Renewable: Those which can be used up (e.g., uranium, coal, oil).

Classification by Origin (Primary vs. Secondary)

• Primary: Obtained directly from nature (fossil fuels, renewable energies).
• Secondary: Produced from a primary source (e.g., electricity generated from coal, or fuels obtained from oil).

Global Energy Consumption and Production

Understanding global energy dynamics requires looking at consumption and production patterns:

• Japan and the EU: Are major consumers but maintain low domestic production levels.
• USA: Consumes and produces an enormous amount of energy.
• India and China: Have significantly increased consumption recently due to rapid development.

Non-Renewable Energy Sources

Oil and Natural Gas

Oil and natural gas are non-renewable fossil fuels formed by the decomposition of living organisms at the bottom of the oceans over millions of years. Their deposits are often found together, which facilitates extraction. Oil provides numerous products, such as petrol.

Coal

Coal is a fossil fuel formed by the decomposing remains of vegetation. It was the main fuel in the 19th century and the first half of the 20th century. Since then, oil and gas have become more important. It is used to produce electricity and is essential for iron and steel production. Coal is the most abundant fossil fuel, but also the one that causes major environmental problems.

Uranium and Nuclear Power

Uranium needs an enrichment process before it can be used, requiring technology that is only available in a few countries. It is used in nuclear power plants and presents specific challenges, such as radioactive waste management.

Renewable Energy Sources

Benefits and Challenges

Advantages:

• Available everywhere.
• Have little impact on the environment.

Drawbacks:

• Supply is irregular.
• It is difficult to store.

Types of Renewable Energy

Key renewable energy types include:

• Hydroelectric
• Wind
• Solar
• Biomass
• Geothermal
• Tidal