JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech IV Year ENERGY SOURCES AND APPLICATIONS Previous Question Paper (July/August - 2022 - R18)

Energy production and consumption are the primary drivers of environmental degradation and global climate change. The environmental impact varies significantly depending on the source, ranging from fossil fuels to renewable alternatives.

1. Greenhouse Gas Emissions and Climate Change: The combustion of fossil fuels (coal, oil, and natural gas) releases large quantities of carbon dioxide (CO2) and methane (CH4). These greenhouse gases trap heat in the atmosphere, leading to global warming, rising sea levels, ocean acidification, and an increase in extreme weather events.

2. Air Pollution: Fossil fuel power plants emit harmful pollutants such as sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter (PM2.5). These contribute to the formation of smog, acid rain, and respiratory illnesses in human populations, as well as damage to ecosystems and agricultural crops.

3. Water Consumption and Contamination: Thermal power plants, including nuclear and coal, require vast amounts of water for cooling, which can lead to thermal pollution when heated water is discharged back into aquatic bodies, disrupting local biodiversity. Additionally, mining and hydraulic fracturing (fracking) for fossil fuels can contaminate groundwater with toxic chemicals and heavy metals.

4. Land Use and Habitat Destruction: Large-scale energy projects often require significant land area. Surface mining for coal destroys topsoil and vegetation, leading to deforestation and loss of wildlife habitats. While renewable sources like solar and wind have lower operational impacts, their large-scale deployment can also lead to land-use conflicts and fragmentation of ecosystems.

5. Radioactive Waste: Nuclear energy, while low in carbon emissions, poses significant long-term environmental risks due to the production of high-level radioactive waste, which requires secure, long-term geological storage to prevent environmental contamination over thousands of years.

6. Mitigation Strategies: Transitioning to a sustainable energy future requires a shift toward low-carbon technologies, such as solar, wind, and geothermal energy, combined with improvements in energy efficiency and the implementation of carbon capture and storage (CCS) technologies to mitigate the environmental footprint of remaining fossil fuel use.

Energy sources are broadly classified into two main categories: Conventional (Non-renewable) and Non-conventional (Renewable) energy sources.

1. Conventional Energy Sources (Non-renewable)
These are finite resources that take millions of years to form and are depleted with use. Examples include coal, petroleum, natural gas, and nuclear fuels.

Advantages:

• High energy density and reliability for base-load power.
• Established infrastructure for extraction, transport, and conversion.
• Generally lower initial capital costs compared to some renewable technologies.

Disadvantages:

• Finite supply leading to eventual exhaustion.
• Significant environmental impact, including greenhouse gas emissions, acid rain, and air pollution.
• Geopolitical risks associated with dependence on fuel imports.

2. Non-conventional Energy Sources (Renewable)
These are naturally replenished on a human timescale. Examples include solar, wind, biomass, geothermal, and tidal energy.

Advantages:

• Environmentally friendly with minimal or zero carbon emissions during operation.
• Inexhaustible supply as they rely on natural processes.
• Reduces dependence on imported fuels and enhances energy security.

Disadvantages:

• Intermittency issues (e.g., solar and wind depend on weather conditions).
• High initial capital investment for technology installation.
• Often requires large land areas and energy storage systems (like batteries) to ensure consistent supply.