Lecture 6: Energy Flashcards
Define energy
Energy - object property which can be transferred to other objects or converted into different forms => CANNOT BE CREATED OR DESTROYED => measured in Joules (J)
Define the forms of energy
• Macroscopic
- Related to motion and external effect influence i.e. gravity, surface tension - e.g. kinetic, potential • Microscopic - Related to systems molecular structure and degree of molecular activity, and are independent of outside references frames e. g. mechanical, chemical, electrical, thermal
Define Economic Aspects of Energy
• Primary energy consumption
- Measure of country total energy demand - Covers: energy sector consumption, transformation losses + energy distribution (i.e. gas->elec), & end user final consumption - Excludes: energy carried for non-energy purposes i.e. petroleum not used for combustion but for producing plastics • Primary production of energy - Energy product extraction in useable form from natural sources - Occurs when natural resources exploited (i.e. coal) or biofuel fabrication - Not primary production examples = energy transformation from one form to another (i.e. electricity) & coke production in coke ovens • Final energy consumption - End user total energy consumption i.e. households/industry - Energy which reaches final customers door Excludes: energy used by energy sector
Types of nonrenewable energy
Coal, oil, natural gas (fossil fuel), nuclear, biomass and wood (if crops not replanted)
Solar energy (energy types)
• Solar
- Energy from sunlight captured on solar panels => converted to electricity
- Advantages = potentially infinite supply, houses can have own electricity supply
Disadvantages = expensive
Wind energy (energy types)
• Wind
- Turbines turn wind to electricity
- Advantages = potentially infinite supply, some single ones but mostly in groups
Disadvantages = expensive, objections from local communities
Tidal energy (energy types)
- Tide movement drives turbines => tidal barrage (dam) built across estuaries => future ones possible at sea without dams
- Advantages = good for islands, generate lots of energy, tidal barrage double as bridge to prevent flooding
Disadvantages = barrage expensive , opposition from environmental groups, may reduce tidal flow and impede sewage flow to sea
- Advantages = good for islands, generate lots of energy, tidal barrage double as bridge to prevent flooding
Wave energy (energy types)
- Seawater movement in and out of cavity on shore compresses trapped air
- Advantages = good for islands, done locally
Disadvantages = expensive, opposition from environmental groups
- Advantages = good for islands, done locally
Geothermal energy (energy types)
- Volcanic regions, use natural heat of earth=> cold water pumped underground, return’s as steam
- Advantages = potentially infinite supply, successful in NZ & Iceland
Disadvantages = expensive, volcanic activity calms down, disposal of dangerous elements from underground
- Advantages = potentially infinite supply, successful in NZ & Iceland
Hydroelectric energy (energy types)
- Energy from water movement through rivers, lakes and dams
- Advantages = creates water reserves
Disadvantages = expensive, cause flooding
- Advantages = creates water reserves
Biomass (Energy types)
- Decaying plant/animal waste => organic material burned to get energy
- E.g. oilseed rape => makes oil => after treatment, used for fuel In diesel engines
- Advantages = cheap & readily available, long-term source
Disadvantages = gives off pollutants when burned, only renewable source if crops replanted
Wood (energy types)
- Energy obtained from burning trees
- Advantages = cheap & readily available, long-term source
- Disadvantages = gives off pollutants when burned, only renewable source if crops replanted
