Understanding Energy and the Laws of Thermodynamics

• Energy is the ability to do work or cause change.
• Energy is essential to all processes.
• Energy exists in many forms: kinetic, potential, thermal, electrical, nuclear, etc.
• Energy powers almost every aspect of daily life, including electricity generation, transportation, heating/cooling, technology, communication, industries, cooking, food, and healthcare.

Law of Conservation of Energy

• Energy cannot be created or destroyed, but it can be transformed from one form to another.
• Example: A roller coaster moving on a track demonstrates conservation.
• At the top: maximum potential energy, minimum kinetic energy.
• As it descends: potential energy converts to kinetic energy.
• At the bottom: maximum kinetic energy, minimum potential energy.

Laws of Thermodynamics

• Energy cannot be created or destroyed, only transferred.
• Entropy (randomness) increases in energy transformations; no transformation is 100% efficient due to heat loss.
• As temperature nears absolute zero, it stops decreasing just above absolute zero.

Earth as a System

• Earth is an open system for energy (solar) and a closed system for matter (limited resources).
• The sun provides energy, but energy is also lost through heat.
• Burning fossil fuels increases entropy by releasing heat and greenhouse gases, contributing to climate change.

Human Energy Production

• Humans transform energy from sources like sunlight and coal into usable forms, such as electricity.
• Total energy is conserved, but the form changes.
• Energy production is never 100% efficient; some energy is lost as waste heat.
• Waste heat contributes to global warming.
• Renewable energy sources are more sustainable because they rely on continuous energy input and produce less entropy than fossil fuels.

Types of Energy

• Potential Energy: Stored energy due to position, condition, or composition (e.g., roller coaster at the top, book on a shelf, stretched rubber band, food, gas, batteries).
• Kinetic Energy: Energy of motion (e.g., moving car, rolling ball, heat from a stove, sunlight, talking, rolling wheel).

Electricity

• Electricity is a form of energy resulting from moving charged particles (electrons/ions).
• Measured in Volts (potential), Watts (kinetic), and kWh (time).
• Generated by converting other forms of energy.

Energy Transformations

• Flashlight: Battery → Electrical energy → light energy + thermal energy (waste).
• Car engine: Gas → combustion → motion of car + waste heat.
• Solar panel: Sunlight → electricity.
• Humans: Food → movement + heat.

Efficiency

• Efficiency is calculated as (Useful Energy Output / Total Energy Input) × 100%.
• Efficiency measures how well a system converts input energy into useful output energy.

Energy Access and Development

• Developed nations: Increased industrialization and technology lead to higher energy demand, more development, and reliance on fossil fuels, which increases greenhouse gas emissions.
• Undeveloped nations: Lack of electricity hinders industry and business development. Lack of access to healthcare, education, and communication creates a wealth gap. Reliance on biomass and fossil fuels for daily life leads to deforestation, air pollution, and health problems, though their global emissions are minimal compared to developed nations.

GDP and Energy

• Higher GDP allows countries to invest in energy infrastructure, advanced technology, and affordable energy.
• Lower GDP leads to struggles in building energy infrastructure and reliance on traditional fuels with health and environmental issues.
• High GDP countries invest in energy such as power plants and grids, adopt advanced tech such as solar and wind, and lead in renewable energy.
• Low GDP countries struggle to build energy infrastructure and rely on traditional fuels which cause health and environmental issues; for example, sub-Saharan Africa does not use a lot of electricity each year.

Changes Over 30 Years

• Emerging countries (China and India): Rapid GDP growth has increased energy access and renewable energy.
• Low GDP areas (sub-Saharan Africa): Slower GDP growth makes it more difficult to obtain energy; over 700 million people globally lack electricity, mostly in low GDP areas.

Global Consumption

• Global energy consumption has increased significantly due to population growth and development.
• Pre-industrial revolution: limited need for electricity; reliance on muscle power; energy for local/basic needs.
• Post-industrial revolution: Electricity is used everywhere daily, largely from burning fossil fuels.

Global CO2 Emissions

• 73% of global CO2 emissions come from energy production:
• Electricity and heat production: 42%.
• Transportation: 24%.
• Industrial: 7%.