Energy Resources Flashcards
technological development timeline
- period of development before practical use
- further development improved: refined, efficient, effective, cheaper
why is it difficult for new technologies to be financially viable during early development?
competition with existing tec, whose costs have been payed for and have economic benefits of mass production
e.g of why it is difficult to calculate full energy costs
e.g burning fossil fuels -> pollution -> acid rain -> financial impacts elsewhere (building damage, crop losses, forestry damage, health affects of atmospheric pollution e.g vehicles)
why do renewable energy projects cost more?
loan needed for spenny equipment (but low running cost) so higher interest payments so at a financial disadvantage
when could a future energy gap be created?
between the time of depleted fossil fuels (or too spenny) and dev of new tec/ infrastructure
enviro impacts of energy consumption
enviro damage could affect political polices and public opinion
increasing affluence and population caused growth in demand which current supplies cannot meet
+ of Nuclear Power
- efficient
- no CO2
- no greenhouse gases
- cheap to produce
- steam produced can heat homes
– of Nuclear Power
- decommissioning plant takes 20 years and very spenny
- produce heat pollution
dangerous e.g Chernobyl - enviro contamination
fission
when neutron slams into large element e.g Uranium 235 forcing it to become larger and more unstable, therefore causing it to fissure and split into 2, releasing huge amounts of energy
fast reactors
maintains the speed of neutrons at high energies
slow reactors
slow thermal neutrons are slowed by heavy isotope water which makes collisions more accurate and frequent, making it more efficient
fast breeder reactors
neutrons causing fission are not slowed by any moderator. Sodium instead of water is used so does not slow the neutrons down
plutonium reactors
a fast breeder reactor where uranium- 238 (not fissile) is converted through neutron bombardment within a reactor to produce new fissile material
thorium reactors
thorium- 232 is not fissile but can be converted to Uranium- 233 which is fissile, as thorium is a fertile fuel
fissile material
material that can undergo nuclear fission when struck with a low energy neutron, e.g Uranium- 235 and plutonium- 239
fertile material
material that can be converted to fissile material to neutron absorption e.g Uranium- 238 and thorium- 232
reactor core
where nuclear fission takes place which contains the fuel e.g uranium and controls pins e.g borium - also where heat is generated
nuclear blanket
surrounds the reactor core that absorbs the energy from the fusion neutrons and removes heat. Also produces Tritium fuel for nuclear fusion
half life
the length of time it takes for the radioactivity of the original isotope to decay by half
the liquid fluoride thorium reactor (LFTR)
has a fertile blanket of thorium fluoride which produces Uranium- 233 after decaying. It is fuel efficient and has a lack of nuclear waste
how is wave power harnessed?
the kinetic energy of the vertical movement of the water/ waves
wave point absorber
a floating structure which rises and falls as waves pass, movement turns a generator
wave overtopping/ terminator device
breaking waves force water into a storage reservoir (above sea level).
water flows back to sea passing through a turbine - generates electricity.
sea walls can be used to increase wave height -> volume of water that enters reservoir
oscillating wave surge converter
as waves pass water moves vertically and horizontally producing a cycle. oscillating movement pushes a flat plate, which moves pistons to pump fluid over a turbine to generate electricity
surface annenuator wave power
a hinged floating device with moving sections that push and pull pistons as waves pass, forcing a fluid over a turbine- generating electricity
oscillating water column wave power
rise and fall of water as waves pass forces water up and down in a submerged chamber.
air is forced in and out of flows over turbines- generating electricity
locational constraints of waver power
kinetic energy is greatest where:
- wind velocities high
- consistent winds in strength and direction (allows wave height to increase)
- long fetch to allow waves to build up
design problems of wave power
- equiptment must be able to withstand storms/ corrosion
- difficult to anchor equiptment off stormy coasts or in deep water
- expensive to transport electricity from isolated areas
environmental impacts of wave power
limited !
- equipt manufacture/ installation affects
- anchoring affects seabeds BUT can also create new habitats
petroleum primary recovery
petroleum in the reservoir trap is forced to the surface by the natural pressure contained in the trap. this pressure may result from several forces
water drive system (primary recovery)
water beneath petroleum presses upwards, when oil is penetrated it is pushed upwards and the water replaces it in the rock pores - most effective
gas cap drive (primary recovery)
if the drill penetrates a layer of oil with a gas cap above it, the gas layer will expand rapidly causing a downwards pressure on oil forcing it to move up through the well
solution gas drive (primary recovery)
gas dissolved in the oil may be released as bubbles when the gas trap is pierced. as the oil moves up, the gas in the oil expands and the growing bubbles push the oil to the surface
why do primary recovery methods only account for 5-30% of the total volume recovered?
loss of natural pressure over time from reduced permeability, increased viscosity and less force driving it through the well
secondary recovery
aims to maintain reservoir pressure by injecting natural gas into the reservoir above the oil, forcing the oil downwards, and then injecting water below the oil to force it upward.
injecting carbon dioxide/ nitrogen into the oil can also be used as it makes the oil more fluid. the primary recovery gas can also be used, or used as a product.
tertiary recovery
most expensive approach, so therefore the least used (COOG) as 12% of petroleum is recovered this way.
it is used to recover the last of oil reserves, after primary and secondary recovery