Energy Flashcards
Primary energy
The potential energy found in natural resources before undergoing any transformation or conversion process
Secondary energy
The total potential energy embodied in an energy carrier after the conversion of a primary energy sourc
Final energy
Energy delivered to consumers
Useful energy
The energy actually used for a task
Latent heat
Hidden energy which is supplied to change the state of a substance
Energy return on investment (EROI)
Measures how much energy is gained from an energy source relative to the energy invested in its extraction and production.
EROI = Energy output/Energy input
Higher EROI indicates more efficient energy production.
Standard EROI
Only includes the energy costs associated with extracting and processing the resource.
Point of use EROI
includes additional energy costs involved in transporting, refining, and distributing the energy.
EROI thresholds
EROI<1 = energy sink
EROI>3 = viable energy source
Net energy
The amount of output energy minus the amount of energy invested
4 attributes of energy
Economics
Energy density
Availability/Abundance
Feasibility
4-Stroke Internal Combustion Engine
Key Steps:
1. Intake: Air-fuel mixture enters the cylinder.
2. Compression: Mixture is compressed.
3. Power: Mixture ignites, pushing the piston.
4. Exhaust: Spent gases are expelled.
Global trends: Major energy sources
Oil: 35%.
Natural Gas: 20%.
Coal: 25%.
Renewables: 20%
Main users of energy
Industry, Transport, and Residential account for 80% of total energy use
4-stroke vs 2-stroke
High power to weight ratio
Ideal for small applications
Higher NOx emissions
