Understanding Energy: Sources and Systems
Energy Essentials
Energy is essential for all events in the universe, from planetary motions to the activities of living beings. It drives tectonic movements, the water cycle, and ocean currents.
Energy Use
Energy is a necessity for all living organisms. Humans utilize two forms of energy:
- Internal energy (endosomatic): Energy consumed for body maintenance.
- External energy (exosomatic): Energy used for operating devices and machines, enabling lighting, heating, transportation, etc.
Energy Systems: Primary and Final Energy
The energy system encompasses all energy-related processes, from original sources to end uses.
Primary energy is the energy entering the system to meet demand. It undergoes transformations until it becomes final energy, used by consumers.
Energy sources are natural resources providing primary energy, which, through technological processes, yield useful final energy.
Non-Renewable Energy Sources
These are finite and generated in slow cycles.
- Fossil fuels: Formed from decomposed microorganisms, plants, and animals buried millions of years ago.
- Radioactive elements: Found in the Earth’s crust, like uranium in pitchblende.
Oil
Oil is a blackish-brown substance composed of hydrocarbons. It’s extracted through drilling and refined into various products.
Natural Gas
Originates from decomposed organic matter, primarily methane. It’s extracted by drilling and transported via pipelines or liquefied for shipping.
Coal
Formed from buried vegetation undergoing carbonization. Types include anthracite, coal, lignite, and peat.
Thermal Power Plants
These plants use fuel to heat water, producing steam that drives turbines to generate electricity.
Radioactive Minerals
Used for nuclear energy through fission reactions, releasing significant energy.
Impacts of Non-Renewable Energy
The use of non-renewable energy sources causes severe environmental impacts due to their finite nature and potential shortages.
Renewable Energy Sources
Hydropower
Produced by falling water, utilizing reservoirs and dams.
Solar Energy
Harnessed through heat energy or photovoltaic conversion using solar panels.
Wind Energy
Utilizes wind turbines to convert wind into electricity.
Tidal Energy
Exploits tidal currents, requiring significant water level differences and suitable coastal relief.
Geothermal Energy
Thermal energy from the Earth’s interior, utilizing geothermal gradients.
Biomass
Organic matter used as an energy source, including biofuels like alcohol and biogas.
Towards a New Global Energy System
The current global energy system is characterized by:
- Predominance of non-renewable sources.
- Significant environmental impacts.
- Imbalance in energy use between developed and developing countries.