8- Energy, Power and Climate Change Flashcards
Albedo (definition)
The ratio of the power that is scattered (reflected) from the surface over total incident power received. It is a ratio and has no units.
Black body radiation
The maximum theoretical amount of radiation that can be emitted from any surface
Carbon dioxide capture and storage
The general term for preventing the release of carbon dioxide into the environment
Coefficient of volume expansion
The fractional change in volume per degree change in temperature, units K^-1
Combined heating and power system
A system that improves the overall efficiency of electricity generation by using thermal energy created to for example supply hot water to people
Degraded energy
Energy that is transferred to the surroundings (thermal energy) is no longer available to perform useful work
Efficiency of coal
35%
Efficiency of gas
45%
Efficiency of oil
38%
Emissivity (definition)
Ratio of power radiated by a body over power radiated by a black body
Power radiated by a body
P = εσAT^4
When a body is a black body, the emissivity, ε, is…
1
Energy balance climate model (equation)
∆T = (Iin - Iout)∆t / Cs
Energy balance climate model (definition)
The variation of temperature of a planet if the incoming and outgoing radiation intensity differ
Energy density
The energy liberated per unit mass of fuel consumed, measured in J/kg
Oscillating water column ocean-wave energy converter
A converter that uses the kinetic energy of waves to generate electrical energy
Pros of fossil fuels
High energy density, extensive distribution network in place
Cons of fossil fuels
Leakage causes environmental problems, need extensive storage facilities
Electricity production process
Fuel, kinetic/thermal energy, rotating turbine, electrical energy
Process of colliding neutrons created in fission to collide with other nuclei to sustain reaction
Chain reaction
Critical mass
Minimum mass of uranium-235 for chain reaction to sustain itself
Moderator
Slows down neutrons in nuclear reactor by causing collisions between them and nuclei of the moderator (often water)
Heat exchanger
Transfers energy to heat water to produce steam to turn a turbine, allowing the nuclear reaction to occur in a sealed off place
Control rods
Movable rods that readily absorb neutrons. They can be introduced or removed from the reaction chamber in order to control the chain reaction
