7.2A Energy sources, global energy consumption and energy choices Notes

Renewable and Non-Renewable Energy Sources

1. Energy is the backbone of modern society, powering everything from homes to industries.
2. But where does this energy come from?

It can be classified into two main categories: renewable and non-renewable sources.

Renewable Energy Sources

Renewable energy comes from natural processes that are continuously replenished.

These sources are often more sustainable and environmentally friendly.

1. Solar Energy

1. Source: The Sun.
2. How it works: Solar panels (photovoltaic cells) convert sunlight into electricity.
3. Advantages:
   1. Infinite supply: The Sun provides more energy in an hour than the world uses in a year.
   2. Low emissions: No greenhouse gases during operation.
4. Disadvantages:
   1. Intermittent: Depends on sunlight availability.
   2. High initial cost: Panels and installation can be expensive.

2. Wind Energy

1. Source: Wind.
2. How it works: Wind turbines convert kinetic energy from wind into electricity.
3. Advantages:
   1. Clean energy: No emissions during operation.
   2. Scalable: Can be used in small or large installations.
4. Disadvantages:
   1. Intermittent: Requires consistent wind.
   2. Environmental impact: Noise pollution and potential harm to wildlife.

3. Hydropower

1. Source: Flowing water.
2. How it works: Dams or rivers drive turbines to generate electricity.
3. Advantages:
   1. Reliable: Provides a steady energy supply.
   2. Multipurpose: Dams can also support irrigation and flood control.
4. Disadvantages:
   1. Ecological impact: Alters river ecosystems and displaces communities.
   2. High cost: Expensive to build and maintain.

4. Geothermal Energy

1. Source: Heat from the Earth's core.
2. How it works: Steam from underground reservoirs powers turbines.
3. Advantages:
   1. Consistent: Not weather-dependent.
   2. Low emissions: Minimal greenhouse gases.
4. Disadvantages:
   1. Location-specific: Requires volcanic or tectonic activity.
   2. High setup cost: Drilling and infrastructure are expensive.

5. Biomass

1. Source: Organic materials (e.g., wood, crop waste).
2. How it works: Burned directly or converted into biofuels.
3. Advantages:
   1. Renewable: If managed sustainably.
   2. Versatile: Can produce heat, electricity, or fuel.
4. Disadvantages:
   1. Emissions: Releases \$CO_2\$ and other pollutants.
   2. Land use: Competes with food production.

6. Tidal and Wave Energy

1. Source: Ocean movements.
2. How it works: Turbines or generators capture energy from tides or waves.
3. Advantages:
   1. Predictable: Tides are regular and reliable.
   2. High energy potential: Oceans cover 70% of Earth's surface.
4. Disadvantages:
   1. High cost: Expensive to develop and maintain.
   2. Environmental impact: May disrupt marine ecosystems.

Non-Renewable Energy Sources

Non-renewable energy comes from resources that are finite and will eventually deplete.

These sources have powered industrial growth but come with significant environmental costs.

1. Fossil Fuels

1. Types: Coal, oil, and natural gas.
2. How they work: Burned to produce heat, which generates electricity or powers engines.
3. Advantages:
   1. High energy density: Efficient for large-scale energy needs.
   2. Established infrastructure: Widely available and used globally.
4. Disadvantages:
   1. Finite supply: Will eventually run out.
   2. Environmental impact: Major source of greenhouse gases and pollution.

2. Nuclear Energy

1. Source: Uranium or plutonium.
2. How it works: Nuclear fission releases heat, which generates steam to drive turbines.
3. Advantages:
   1. Low emissions: Minimal greenhouse gases during operation.
   2. High energy output: Small amounts of fuel produce large amounts of energy.
4. Disadvantages:
   1. Radioactive waste: Long-term storage is a major challenge.
   2. Safety risks: Accidents like Chernobyl and Fukushima highlight potential dangers.

Why Does This Matter?

1. Environmental Impact: Fossil fuels are the largest contributors to climate change, while renewables offer cleaner alternatives.
2. Energy Security: Countries with diverse energy sources are less vulnerable to supply disruptions.
3. Sustainability: Transitioning to renewables is essential for meeting global energy needs without depleting resources.

Energy Supply and Demand: Addressing the Growing Challenge

1. Global energy consumption is increasing due to rising populations and higher per capita demand.
2. While fossil fuels still dominate global energy supply, the use of renewable energy sources is steadily growing.
3. However, industries like steel, concrete, and synthetic fertilizers still heavily rely on fossil fuels, meaning dependence on them will likely persist for some time.

Changes in Energy Production and Consumption:

Global Changes:

1. Shift to Renewables:
   1. The global push for cleaner energy sources, such as solar, wind, and hydropower, has led to significant investments in renewable energy.
   2. Countries like Germany and China are leading the transition, with increased renewable capacity.
2. Energy Storage Innovations:
   1. Advancements in energy storage, such as battery technologies, are improving the reliability of renewable energy sources, enabling better integration into the grid.
3. Challenges with Fossil Fuels:
   1. Despite the rise of renewables, fossil fuels continue to be critical for heavy industries like steel production, which is energy-intensive and typically powered by coal.

Reasons for Changes:

1. Environmental Concerns:
   1. Global awareness of climate change and the need to reduce carbon emissions is driving the shift toward renewable energy.
2. Technological Advancements:
   1. Improvements in renewable energy technology, such as more efficient solar panels and wind turbines, are making renewables more economically viable.
3. Economic Factors:
   1. Renewable energy is becoming more cost-competitive with fossil fuels, especially as fossil fuel prices fluctuate.
   2. Additionally, the falling cost of renewables makes them more attractive for both developed and developing nations.
4. Government Policies:
   1. Policies like the Paris Agreement and national commitments to net-zero emissions are encouraging governments to reduce fossil fuel dependence and invest in renewable energy infrastructure.

Sustainability of Energy Sources: A Comparative Overview

The sustainability of various energy sources depends on factors such as environmental impact, resource availability, and the ability to restore ecosystems affected by their extraction and use.

Fossil Fuels (Coal, Oil, Natural Gas)

Sustainability:

1. Fossil fuels are non-renewable and deplete over time.
2. They contribute significantly to greenhouse gas emissions, which are the primary drivers of climate change.
3. Extracting fossil fuels, such as coal mining or drilling for oil and gas, leads to habitat destruction, pollution, and long-term ecosystem damage.

Environmental Impact:

1. Air pollution from burning fossil fuels is a major concern, contributing to smog and acid rain.
2. Carbon dioxide (CO₂) and methane (CH₄) emissions are major contributors to global warming.
3. Restoration of environments after fossil fuel extraction is often difficult and costly, as the land and ecosystems are heavily damaged and polluted.

Rare Earth Elements (REEs)

Sustainability:

1. Rare earth elements are used in technologies such as batteries, wind turbines, electric vehicles (EVs), and smartphones.
2. Mining these minerals is energy-intensive and environmentally damaging, often involving the destruction of ecosystems and the creation of toxic waste.

Environmental Impact:

1. Mining of REEs can result in the contamination of soil and water sources with heavy metals and radioactive substances.
2. Mining practices, especially in countries like China, are often not environmentally regulated, leading to significant environmental harm.
3. The end-of-life recycling of REEs from electronics is challenging due to the difficulty of extracting these materials from complex products.

Nuclear Energy

Sustainability:

1. Nuclear energy produces a large amount of electricity with low greenhouse gas emissions.
2. However, nuclear power relies on uranium, a finite resource, and involves significant environmental costs in mining, waste disposal, and the decommissioning of plants.

Environmental Impact:

1. The extraction of uranium involves habitat destruction and water contamination.
2. Nuclear waste, which remains hazardous for thousands of years, presents long-term environmental challenges.
3. Safe storage and management of nuclear waste are crucial to preventing contamination of land and water.

Solar Energy

Sustainability:

1. Solar energy is renewable and generates electricity without emitting greenhouse gases during operation.
2. The production and disposal of solar panels involve environmental costs, including energy-intensive manufacturing processes and the use of hazardous materials.

Environmental Impact:

1. Mining for materials like silicon, cadmium, and rare earth elements for solar panels can cause habitat disruption and pollution.
2. End-of-life disposal of solar panels presents challenges, as they can be difficult to recycle due to the variety of materials used.
3. Solar power requires large areas for installation, potentially affecting land use and biodiversity.

Wind Energy

Sustainability:

1. Wind energy is a renewable resource with minimal environmental impact during operation.
2. The main environmental cost comes from the manufacturing, installation, and decommissioning of wind turbines, which require the extraction of raw materials and the transportation of large equipment.

Environmental Impact:

1. Construction and transportation of turbines can cause habitat disturbance and involve a carbon footprint from production and transportation.
2. Bird and bat mortality due to turbine blades is a concern, although this is largely mitigated through careful siting of wind farms.
3. The lifespan of wind turbines is around 20-25 years, and recycling of materials such as blades can be difficult.

Comparison of Sustainability

Energy Choices and Their Influencing Factors: A Comparative Analysis

Countries make energy choices based on a range of factors, including sustainability, economic cost, pollution, energy efficiency, availability, and energy security.

The energy mix chosen by each country depends on its unique set of circumstances, such as available resources, infrastructure, economic priorities, and environmental policies.

Norway

Norway is a wealthy, highly developed nation with abundant natural resources, including hydropower, oil, and natural gas.

The country has made significant progress in reducing greenhouse gas emissions and increasing renewable energy sources.

Advantages of Energy Sources in Norway:

Hydropower (Renewable)

1. Sustainability: Hydropower is Norway’s primary energy source, generating about 96% of the country’s electricity. It is sustainable as it relies on water cycles and produces no greenhouse gas emissions during operation.
2. Economic Cost: While the initial investment in infrastructure (dams, turbines) can be high, the long-term operational costs are relatively low, making hydropower economically competitive.
3. Energy Efficiency: Hydropower has a very high energy efficiency compared to other sources, with efficiency rates of around 90%.
4. Availability & Energy Security: Norway's topography, with vast rivers and mountain ranges, makes hydropower a reliable and secure source of energy.
5. Pollution: The main environmental concern is the impact of dams on local ecosystems, particularly aquatic life and river systems.

Oil and Natural Gas (Non-Renewable)

1. Economic Cost: Norway benefits economically from its oil and gas exports, making it one of the wealthiest countries in the world.
2. Energy Security: As a major exporter of oil and gas, Norway’s energy security is enhanced by its control over substantial fossil fuel reserves.
3. Pollution: The extraction and burning of fossil fuels lead to significant carbon emissions. However, Norway has invested heavily in carbon capture and storage (CCS) technologies to mitigate emissions from its oil and gas industries.

Disadvantages of Energy Sources in Norway:

Hydropower

1. Environmental Impact: While hydropower is generally clean, dam construction and reservoir creation can result in significant environmental and social consequences, such as habitat loss, displacement of local communities, and changes in water quality.

Oil and Gas

1. Sustainability: Fossil fuel extraction and consumption are not sustainable in the long term, contributing to climate change. Norway has committed to reducing its reliance on oil and gas, but it remains a major economic driver.
2. Pollution: Oil spills and natural gas leaks contribute to pollution, and the extraction process can harm surrounding ecosystems.

India

India is a rapidly developing country with a growing population and increasing energy demand.

Its energy choices are influenced by the need to balance economic growth, energy security, and environmental sustainability.

Advantages of Energy Sources in India:

Coal (Non-Renewable)

1. Availability: India has vast coal reserves, making coal a readily available and reliable source of energy.
2. Economic Cost: Coal is a cheap source of energy, and the cost of coal-fired power plants is relatively low compared to other energy sources, making it attractive for a country like India, where economic growth and affordability are priorities.
3. Energy Security: Coal provides energy security by ensuring a stable and consistent domestic energy supply, reducing dependency on imports.

Solar Energy (Renewable)

1. Sustainability: Solar energy is a renewable and sustainable resource. India has abundant sunlight, particularly in regions like Rajasthan and Gujarat, making solar energy an increasingly viable option.
2. Economic Cost: The cost of solar energy has been falling steadily due to technological advances, making it a competitive and affordable alternative.
3. Energy Efficiency: Solar panels have relatively low efficiency compared to some other energy sources, but improvements in technology are rapidly increasing their performance.
4. Pollution: Solar energy produces no emissions during operation, making it an environmentally friendly energy source.
5. Energy Security: As a nation with vast unused land, India has significant potential for solar energy generation, reducing reliance on imported fossil fuels.

Disadvantages of Energy Sources in India:

Coal

1. Pollution: Coal burning is one of the largest sources of air pollution in India, contributing to severe smog, respiratory diseases, and global warming due to high carbon emissions.
2. Sustainability: The long-term sustainability of coal is in question due to its finite nature and environmental impact.
3. Economic Cost: Although coal is initially cheaper, the external costs (e.g., health impacts and environmental damage) are significant, leading to higher overall costs in the long term.

Solar Energy

1. Availability: While India has vast solar potential, the infrastructure for widespread adoption is still underdeveloped. Solar energy generation is also weather-dependent and varies by region and season.
2. Energy Efficiency: Solar power is intermittent, meaning it cannot supply constant energy without storage solutions, which are currently expensive and inefficient.