Energy Resources: Nonrenewable and Renewable

Coal

• Nonrenewable energy resource.

• Formation: from fossilized remains of prehistoric plants and animals. Key sequence: peat → lignite → coal, driven by time, pressure, and heat.

  • Diagrammatic idea: Time, Pressure, Heat → Coal.

• Uses: energy for cement production, transportation, and heating.

  • Production of cement: coal is combusted to generate the heat required to fire kilns that produce cement.

  • Transportation: coal powers steam in trains.

  • Heating: coal used for heating residential and commercial buildings.

• Coal advantages

  1. No shortage anytime (as presented in the material)

  2. Inexpensive

  3. Reduces dependence on oil

  4. Creates jobs

• Coal disadvantages

  1. Environmental impacts (burning, by-products, acid rain, increased greenhouse gases)

  2. Mining impact on the land

  3. Impact on miners’ health

Oil

• Petroleum origin: from Latin words Petra (rock) and oleum (oil).

• Formation: derived from large quantities of microscopic aquatic organisms such as algae and plankton.

  • Process: Mud rich in dead plankton → buried mud layers in oceans/lakes → plankton decays; bacteria digest plankton into ooze, which becomes oil.

• Uses: main transportation fuel incl. gasoline, diesel, jet fuel; also asphalt for paving roads.

  • Asphalt: petroleum used to produce asphalt for roads, highways, and airport runways.

• Oil advantages

  1. Small amount produces a lot of energy

  2. Easy to transport

  3. Easy to produce

  4. Constant reliable resource for years to come

• Oil disadvantages

  1. Emits greenhouse gases

  2. Spills cause water and land pollution

  3. Harmful emissions from plants can make people sick

Natural Gas

• Formation: formed from layers of buried plants, gases, and animals exposed to intense heat and pressure over years; made by methane and other hydrocarbons.

• Properties: flammable, colorless, and odorless.

• Uses: cooking (precise temperature, quick heating).

• Nonrenewable Energy Resources – Natural Gas

• Advantages

  1. Gas leaks can be dangerous; can cause explosions

  2. Burns cleaner than coal/oil

  3. More abundant

  4. Safer

  5. Cheaper

  6. Best among fossil fuels (in some comparisons in the material)

• Disadvantages

  1. Gas infrastructure for production and distribution is expensive

  2. Burning releases greenhouse gases

  3. (Implied) Not as widely available or scalable as some other fuels in all regions

Nuclear Energy

• Definition: nonrenewable resource that produces about $11\%$ of the world’s energy.

• Energy production method: nuclear power stations use fission to generate heat that creates steam to drive turbines and generate electricity.

• Nuclear fission basics: neutrons smash into Uranium or Plutonium atoms, releasing energy as heat.

• Nuclear Power Plant components (as depicted):

  • Reactor → Turbine → Generator → Steam → Cooling water → Cooling tower → Water condenser

  • Heat source creates steam that drives turbines; cooling systems manage heat.

• Nuclear advantages

  1. Low air pollution

  2. Reliable energy source

  3. Low cost to produce electricity once built

  4. A lot of energy from a small amount of fission material

  5. Easily transported fuel and equipment

• Nuclear disadvantages

  1. Environmental impact from mining uranium

  2. High cost to secure/manage radioactive waste

  3. Expensive to build plants and purchase fuels

  4. Accidents at plants are costly and dangerous

Solar Energy

• Solar energy is one of the best renewable energy sources; it is a clean source of energy.

• Mechanisms: conversion of sunlight into electricity either directly via photovoltaic (PV) cells or via concentrated solar power (CSP).

• Solar energy concepts:

  • Passive solar: relies on the natural design of buildings and materials to collect, store, and distribute heat without mechanical devices.

  • Active solar: uses mechanical and electrical systems to capture, convert, and distribute solar energy for power at large scales.

• Solar advantages

  1. Relatively simple technology

  2. Little maintenance

  3. Reliable and quiet

  4. Free energy after purchasing solar panels

• Solar disadvantages

  1. Energy cannot be generated at night

  2. Cloud cover reduces power

  3. Works best at the optimal angle toward the sun

  4. Only converts about $20\%$ of the sun’s energy to electricity

Wind Energy

• Wind energy: movement of air caused by differences in atmospheric pressure.

• History: wind power was used in the Middle Ages in Europe to grind corn (origin of the term “windmill”).

• Mechanism: wind turbines convert kinetic energy in the wind into mechanical energy.

• How it works: wind turns blades, the turbine spins a generator, transformers at substations increase voltage, electricity is fed to the grid.

• Advantages

  1. Wind is free; wind farms require no fuel

  2. Produces no waste or greenhouse gases

  3. Land beneath can still be used for farming

  4. Wind farms can be a tourist attraction

  5. Useful for supplying energy to remote areas

• Disadvantages

  1. Wind is not always predictable; some days have no wind

  2. Suitable sites are near coasts where land can be expensive

  3. Aesthetics: wind towers may be considered unsightly

  4. Can kill birds, especially migrating flocks in strong winds]

  5. Can affect television reception if you live nearby

Geothermal Energy

• Definition: heat energy from deep within the Earth; water is warmed by magma and pumped to the surface; steam can be used to turn a turbine.

• Example: 90% of people in Iceland use this heat source.

• Example facility: Mahanagdong Geothermal Power Station in Ormoc, Leyte.

• Geothermal advantages

  1. Clean

  2. Does not require another fuel source to produce it

  3. Does not emit harmful pollutants into the air

• Geothermal disadvantages

  1. Not a widespread energy source

  2. High installment costs to build power plants

  3. Not easily transported

Hydropower (Water Power)

• Description: power derived from the energy of falling water or fast-moving water, harnessed to generate electricity.

• Key components: reservoir, intake, penstock, dam, powerhouse, long-distance power lines, generator, turbine, river.

• How it works: flowing water creates energy captured and turned into electricity.

• Hydroelectric system diagram (simplified): Reservoir → Intake → Penstock → Dam → Powerhouse → Generators/Turbines → Transmission lines → Grid

• Advantages

  1. Energy is inexpensive to harness

  2. Rivers are widespread; resources are available

  3. Reliable since flow can be controlled by engineers

• Disadvantages

  1. Dam construction causes environmental impact for people, plants, and wildlife

  2. Reservoirs depend on rainfall to fill

  3. Expensive to build a dam

Biomass

• Definition: energy from materials that come from plants or microorganisms that were recently living.

• Examples: trees, branches, bark scraps, recycled paper; biomass energy comes from burning these materials; biofuel is produced when mixed with gasoline (e.g., ethanol).

• Biomass sources: forestry residues, industrial residues, agricultural crops & residues, animal residues, sewage, municipal solid waste.

• Summary idea: energy from organic material; can be stored and used as needed; can release fewer pollutants than gasoline but has land-use and pesticide considerations.

Carbon Cycle (relevant to bioenergy and emissions)

• Basic flow:

  • Sunlight → photosynthesis → organic carbon stored in living organisms

  • Decay of organisms releases CO₂

  • Animal respiration and root respiration return CO₂ to the atmosphere

  • Fossils and fossil fuels form from long-term storage of carbon

• Important pollutant links: human activities (auto and factory emissions) contribute to CO₂ and other greenhouse gases influencing climate patterns

Key concepts and comparisons

• Nonrenewable vs Renewable resources:

  • Nonrenewable: Coal, Oil, Natural Gas, Nuclear

  • Renewable: Solar, Wind, Geothermal, Hydropower, Biomass

• General statement on renewability: Energy resources which naturally renew or replenish over time

• The question for reflection: "Do you think we can quit from using fossil fuels? Why?" (prompt to consider feasibility, timeline, and impacts)

Ethical, practical, and real-world implications

• Environmental impacts of fossil fuels include greenhouse gas emissions, acid rain, oil spills, habitat disruption from mining, and health risks to workers and nearby communities

• Transition considerations: reliability, cost, infrastructure, safety, and energy equity; trade-offs between immediate energy needs and long-term sustainability

• Policy and societal implications: energy security, job creation in new sectors, retraining workers, and investment in renewables vs. continued fossil fuel use

Connections to broader principles

• Energy density and transportability:

  • Fossil fuels offer high energy density and established infrastructure

  • Renewables provide lower density or variability, requiring storage, grid adaptation, or diversification

• System-level thinking:

  • Electricity generation mixes, transmission grids, and regional resource availability influence feasibility and reliability

• Environmental ethics:

  • Balancing current energy needs with stewarding ecosystems and public health

Notes on numerical references and formulas

• Nuclear energy contribution: $11\%$ of the world’s energy supply

• Solar conversion efficiency example: up to $20\%$ efficient conversion of sunlight to electricity

• Other numerical claims are qualitative as presented in the transcript (e.g., advantages/disadvantages listed as enumerated points)