ENV100: Fossil Fuels Notes

Quiz 3: Available now. Closes Feb 16 at 11:59.
Midterm Exam: Corrected grades will be posted on Feb 10.
- Error due to row offset in Excel, found thanks to students!
- Average Score: 47.3, Standard Deviation: 17.9, Range: 7 to 96.

Energy Resources:
- Non-renewable: coal, oil, natural gas, nuclear energy, unconventional fossil fuels (oil sands, shale gas).
- Renewable/Replenishable: hydropower, biomass, wind, solar.

Renewable Energy: Sources replenished over short timescales (e.g., wind, solar).
Inexhaustible Energy: Vast energy reserves, effectively limitless (e.g., solar).
Nonrenewable Energy: Finite sources that cannot be replenished in a human-relevant timescale (e.g., fossil fuels).

Power: Rate of energy transformation (measured in watts, 1 ext{ watt} = 1 ext{ joule/second}).
Energy: ext{Energy} = ext{Power} imes ext{Time},
- Example: A 60-watt bulb uses 60 joules/second.
Consumption Measurement: 1 kWh = energy used by 1 kilowatt over 1 hour.

Fossil fuels derive from buried organic materials (plants and animals) subjected to heat and pressure over millions of years.
Key Processes: Decomposition under low oxygen conditions forming kerogen, which matures into hydrocarbons through thermal cracking.

Fossil fuels comprise a significant portion of current energy use, despite increasing alternatives.
- Growth is primarily observed in developing countries.

Coal: Developed from the decomposition of plant material.
- Major grades: Peat, lignite, sub-bituminous, bituminous, anthracite (differ in carbon content and calorific value).
Petroleum: Formed from marine organic matter under heat and pressure; crude oil is refined into various products.
Natural Gas: Composed mainly of methane, it can occur alongside oil and has become integral for energy consumption.
- Historical extraction began in 1821; now significant for heating and cooking.

Natural gas and oil extraction may involve primary methods (initial pumping) and secondary methods (enhanced recovery techniques).
Fracking: High-pressure fluid injection used to extract tight oil and gas from low-permeability rocks.

Coal Mining: Associated with considerable environmental degradation, including land contamination, air pollution, and risk of health issues.
Oil and Gas: Extraction and use lead to environmental contamination, infrastructural damage, and significant greenhouse gas emissions.

Fuels that require complex extraction methods and may result in higher environmental costs (e.g., tar sands, shale oil).
Majority of unconventional oil and gas is extracted via fracking.

Global reserves are finite, but economic feasibility complicates extraction decisions.
Peak Oil: The point when oil production reaches its maximum rate before declining.
- Current consumption outpaces discovery; global reliance on fossil fuels raises geopolitical concerns.

Fossil fuels remain critical for energy consumption, however, their environmental impact and sustainability issues pose challenges.
Strategic transition to cleaner energy alternatives is essential for sustainable future energy security and environmental preservation.