PHYSICS S5 Unit 6: Fossil and Non-Fossil Fuel and Power Production

The course Unit 6: Fossil and Non-Fossil Fuel and Power Production is typically found in Environmental Science, Physics, or Engineering curricula. It provides a comprehensive survey of the energy sources that power modern society, focusing on their origins, the process of generating electricity from them, and the environmental impact of each.

1. Fossil Fuels and Their Impact

This section covers the non-renewable resources that currently dominate global energy production.

1. Fossil Fuel Types

• Coal: Formed from ancient plant matter; categorized by carbon content (e.g., lignite, bituminous, anthracite). Primary source for electricity generation globally.
• Petroleum (Oil): Liquid hydrocarbon derived from ancient marine organisms. Crucial for transportation and petrochemicals, but also used for power generation.
• Natural Gas: Primarily methane (CH₄). Cleaner-burning than coal or oil, often used in combined-cycle power plants for high efficiency.

2. Power Generation (Thermal Plants)

You will learn the basic process of a thermal power plant (applicable to coal, oil, gas, and nuclear):

• Fuel is burned (or fissioned) to heat water and produce high-pressure steam.
• The steam turns a turbine.
• The turbine spins a generator, which produces electricity.

3. Environmental and Economic Impact

• Greenhouse Gases: The primary drawback is the release of carbon dioxide (CO₂) and other greenhouse gases, contributing to climate change.
• Pollutants: Release of sulfur dioxide (SO₂), nitrogen oxides (NO_x), and particulate matter, leading to acid rain and smog.
• Resource Depletion: They are non-renewable; reserves are finite.

1. Non-Fossil (Non-Conventional) Energy

This section focuses on energy sources that are renewable or do not rely on combustion of carbon-based fuels.

1. Renewable Energy Sources

• Solar Energy: Direct conversion of sunlight into electricity using photovoltaic (PV) cells or concentrating solar power (CSP) to generate heat.
• Wind Energy: Harnessing wind kinetic energy to spin turbines. You will study the factors influencing turbine placement (e.g., wind speed, land use).
• Hydroelectric Power: Using the potential energy of water stored behind a dam to spin turbines. Highly reliable but with significant ecological impacts (e.g., habitat loss, altered river flow).
• Biomass: Energy derived from organic matter (e.g., crops, wood, waste). Considered carbon-neutral if growth equals consumption, but controversial due to land use and air pollution.
• Geothermal: Utilizing heat from the Earth’s core (usually steam or hot water) to drive turbines.

2. Nuclear Energy

• Mechanism: Uses controlled nuclear fission (splitting of atoms, typically Uranium-235) to produce intense heat, which then drives a steam turbine.
• Advantages: Extremely high energy density and zero greenhouse gas emissions during operation.
• Drawbacks: Management of radioactive waste and the low-probability, high-consequence risk of accidents (e.g., Chernobyl, Fukushima).

III. Energy Policy and the Future

The unit often concludes with a look at the challenges and opportunities in the global energy landscape:

• Energy Efficiency and Conservation: Strategies to reduce energy demand.
• Grid Infrastructure: The challenges of integrating intermittent sources (solar, wind) into the existing electrical grid.
• Comparative Analysis: Evaluating different sources based on cost, reliability, scalability, and environmental externalities.