Energy and the Environment: Exhaustive Study Guide

Global Energy Context and the Link to Climate Change

• The Necessity of Energy and its Environmental Impact: Many scientists agree on a direct link between the burning of fossil fuels (oil, coal, and gas) and global climate change.
• The Political and Economic Trade-off: Fuel is described as enormously useful, valuable, and politically significant. However, tackling global warming may necessitate leaving untapped reserves in the ground to prevent further carbon emissions.
• Sustainability Questions: Several critical questions arise regarding the future of energy:
  • Could the world ignore unextracted oil, coal, and gas reserves to prevent carbon emissions?
  • How would vehicles operate without traditional fossil fuel sources?
  • Can the world cope with alternative forms of energy production?
  • Will international governments cooperate to transition away from these fuels?

Demand for Energy and Changing Consumption Patterns

• Global Trends: Global energy use is predicted to continue increasing over the next $40$ years.
• Resource Availability: While non-renewable resources are limited, new deposits and higher prices have made previously inaccessible resources economically viable, extending their availability.
• Pricing: The world price of non-renewable energy is expected to rise as demand increases.
• Variation by Country: Energy use per person varies significantly between nations due to several determining factors:
  • Industrial Demand: Industrialized societies use far more energy per person than traditional farming communities. Manufacturing requires massive energy at every stage. Specifically, iron and steel production requires high energy to melt and refine metals. Technological advances make products cheaper and more like commodities, which increases production and energy demand.
  • Domestic Demand: Improved manufacturing has made goods (cars, computers, televisions) more affordable and common. Rising living standards and social expectations drive household energy use. For example, consumer expectations for year-round availability of fresh produce necessitate energy-intensive transport or production.
  • Transport Demand: Global manufacturing and trade have increased shipping and air transport significantly. Despite high costs, global trade remains profitable due to cheap production in specific regions.
  • Economic Factors: Demand is tied to national and individual wealth. Energy use falls during economic declines. A downturn in a major economy, such as China, reduces global demand for goods, transport, and oil. Historically, a strong world economy correlates with high energy use.
  • Climate Factors: Colder countries require more energy for heating and lighting. Fewer daylight hours in winter increase electricity use. Climate change leads to extreme weather, further raising energy needs for both heating and air conditioning.

Fossil Fuels: Composition and Formation

• Definition: Fossil fuels are carbon-based fuels formed over millions of years from the decay of living matter.
• Direct Combustion: Energy is often used through the burning of carbon-dense substances to produce heat and light.
• Types of Fossil Fuels:
  • Natural gas.
  • Coal.
  • Oil.
• The Process of Coal Formation:
  1. Huge forests grew millions of years ago, covering much of the Earth.
  2. Vegetation died and formed peat.
  3. Peat was compressed between sediment layers to form lignite.
  4. Further compression over millions of years formed coal.
• The Process of Oil and Gas Formation:
  1. Small marine organisms lived in the ocean roughly $300$ to $400$ million years ago.
  2. As they died, they were covered by sediment and rock.
  3. Over $50$ to $100$ million years, the combination of pressure and heat turned these organisms into oil and natural gas.
  4. Today, these are found trapped under impermeable rock within porous sedimentary rock layers.

Energy Resource Classification

• Non-Renewable Energy: Resources with a limited supply that cannot be replaced once used.
  • Examples: Oil, Coal, Natural gas, Nuclear power.
• Renewable Energy: Resources that can be replenished and will not be used up.
  • Examples: Geothermal power, Hydroelectric power, Tidal power, Wave power, Wind power, Solar power, Biofuels (bioethanol, biogas, wood).

Electricity Generation and Technical Principles

• Electromagnetic Induction: Discovered by Michael Faraday in the $1820s$, this process transforms kinetic energy (movement) into electrical energy.
• The Generator Mechanism: Loops of conducting material (like copper) and a magnet are used. Rotating the coils close to the magnet generates electricity.
• The Role of the Turbine: A power source is needed to rotate the generator coils. A turbine, consisting of blades on a shaft, is used. Rotary motion is achieved by passing a stream of liquid or gas over these blades.
• Geothermal Energy Production Step-by-Step:
  1. Cold water is pumped under pressure into a layer of hot rocks (located between $4000$ and $4500$ meters deep).
  2. The rocks heat the water, which returns to the surface under pressure.
  3. This hot water enters a heat exchanger to heat a second, separate supply of water.
  4. The steam produced from the second supply moves a turbine, which powers the generator.
  5. The water is then re-used in the system.

Economic and Social Factors in Energy

• Investment and Infrastructure: High investment costs for technology act as a barrier to renewable energy, even in countries with abundant natural resources like consistent sunlight or geothermal heat.
• Local Supply Advantages: Countries like the USA (coal), Russia (natural gas), and the Middle East (oil) benefit from local fuels.
• Australian Gas Price Exception: Consumers on Australia's east coast often pay more ($8-11\,giga-joule^{-1}$) for domestic natural gas than Asian customers pay for Australian exports (less than $6\,giga-joule^{-1}$).
• Social Impacts:
  • Jobs: Energy projects create employment but can also lead to the decline of traditional industries.
  • Infrastructure: Projects can bring better roads, healthcare, and schools.
  • Displacement: Large projects, like hydroelectric dams, can flood valleys and displace entire communities.
  • Health: Risks include air pollution, dust, and radiation.

Environmental Consequences of Energy Use

• Pollution: Oil spills harm marine life, and burning fossil fuels releases toxic gases and $CO_2$.
• Habitat Destruction: Extraction methods can destroy ecosystems. Even renewables have impacts, such as dams blocking fish migration or solar/wind farms altering landscapes.
• Carbon Balance in Biofuels: Biofuels release $CO_2$ when burned, but the plants used to create them absorb $CO_2$ during growth, creating a partial balance.

Conservation and Energy Management Strategies

• Reducing Consumption through Insulation:
  • Roof (Loft) Insulation: The most effective method, as $30-35\%$ of heat is lost through roofs.
  • Walls: Account for $18-25\%$ of heat loss. Cavity wall insulation is more effective than air gaps.
  • Windows: Account for $21-31\%$ of heat loss. Double/triple glazing uses sealed air or argon-filled gaps for insulation.
  • Other losses: Air leakage ($6-9\%$).
• Electrical Efficiency:
  • Devices on standby (TVs, computers) use about $15\,W$. Leaving 4 or 5 devices on standby is equivalent to keeping one light bulb on permanently.
  • Purchasing energy-efficient appliances and vehicles is crucial.
• Case Study: USA Car Efficiency: Average car efficiency improved from $15\,\text{miles per gallon} \, (6\,km/l)$ in $1975$ to $33\,\text{miles per gallon} \, (14\,km/l)$ in $2010$.
• Scrappage Schemes: Governments pay consumers to trade in old, inefficient machines to promote recycling and reduce pollution.
• Energy from Waste:
  • Anaerobic Digestion: Bacteria break down organic waste in sealed containers to produce methane for heating and compost for soil.
  • Incineration: Burning household rubbish for heat/electricity; produces ash and some toxic gases.
  • Cooking Oil: Recycling waste oils into biodiesel for vehicles.

Education and Policy

• Barriers to Change:
  • Attitude-behaviour gap: People value the environment but do not act consistently.
  • Status quo bias: Preference for familiar systems (like gas heating).
  • Economic factors: Valuing immediate rewards over future savings.
• Government Actions:
  • Energy-efficiency labels.
  • Stricter building regulations.
  • Bans on inefficient products (e.g., traditional light bulbs).
  • Grants for home insulation or vehicle scrapping.
• Transport Policies:
  • Zurich vs. Sydney: Zurich relies $47\%$ on public transport with only $12\%$ private car use, while Sydney has $68\%$ private car use. This results in $0.55\,\text{tonnes of } CO_2 \text{ per person}$ in Zurich versus $1.86\,\text{tonnes}$ in Sydney.
  • Government Initiatives: Regulations on exhaust gases (Euro 6 standards), restrictions on vehicle access (London ULEZ), and fuel taxation (Norway).

Hydraulic Fracturing (Fracking)

• The Debate:
  • Pro-Fracking Arguments: Accesses limited oil/gas reserves; produces less pollution than coal; reduces imports; provides local jobs; drilling occurs far below the water table.
  • Anti-Fracking Arguments: Risk of toxins entering the water table; chemical mixtures are toxic; uses excessive water; causes noise pollution; destroys natural areas; may cause earth tremors; long-term impacts are unknown.

Management of Oil Pollution

• Historical Major Oil Spills:
  • Kuwait Oil Lakes (1991): $5000\,\text{thousand tonnes}$ (War).
  • Lakeview Gusher, USA (1910): $1200\,\text{thousand tonnes}$ (Onshore extraction).
  • Deepwater Horizon, USA (2010): $575\,\text{thousand tonnes}$ (Offshore extraction).
  • Ixtoc 1, Mexico (1979): $475\,\text{thousand tonnes}$.
  • Atlantic Express, Trinidad and Tobago (1979): $287\,\text{thousand tonnes}$ (Tanker collision).
• Ecological Impacts:
  • Mammals: Dolphins and whales swallow oil (toxic) and suffer skin damage; food sources are depleted.
  • Reefs: Slicks block sunlight, preventing photosynthesis in phytoplankton/plants. Lack of oxygen leads to species death.
  • Beaches: Oil coats rocks and kills organisms in rock pools/shallow water.
• Social Impacts: Reduction in fish populations affects livelihoods and food security; tourism declines as beaches become unattractive.
• International Regulation (MARPOL): The International Convention for the Prevention of Pollution from Ships (established $1973/1978$, enforced $1983$). It regulates the release of oil, sewage, rubbish, and toxic chemicals. Violators face large fines or port detention.
• Tanker Design: Modern tankers use Double-hulled construction. Two layers of plates ensure that if the outer hull is punctured, the inner hull remains intact to contain the cargo.
• Cleanup Strategies:
  • Floating booms: Barriers to contain the oil on the surface.
  • Detergent sprays: Chemicals that break the oil into smaller droplets.
  • Skimmers: Devices that remove oil from the water surface.

Technical Definitions and Units

• Watt (W): A unit of power defined as $1\,\text{joule per second}$ ($P = V \times I$).
• Kilowatt-hour (kWh): Equal to using $1000\,\text{watts}$ for $1\,\text{hour}$.
  • Example: A $100\,\text{W}$ bulb running for $10\,\text{hours}$ uses $1\,kWh$.
  • Example: You must charge an iPhone approximately $200$ times to use $1\,kWh$ (assuming a $5\,W$ charger).
  • Utility of $1\,kWh$: Powers a modern fridge for $20\,\text{hours}$, toasts $89\,\text{slices of bread}$, or drives an electric car $3.6\,\text{miles}$.
• Fuel Comparison (Running a 100W bulb on 1kg of fuel):
  • Wood: $1.2\,\text{days}$.
  • Coal: $3.8\,\text{days}$.
  • Oil: $4.8\,\text{days}$.
  • Uranium (Fission): $20,000\,\text{days}$.
  • Hydrogen-Boron (Fusion): $3,300,000\,\text{days}$.