energy recources

Question 1

how is coal, oil and gas produced in a power station

Answer 1

• the burning fuels heat water in a boiler, producing steam
• the steam drives a turbine that turns a generator

Question 2

name an example of a biofuel

Answer 2

methane from animal manure, sewage or decaying rubbish

Question 3

what is a biofuel

Answer 3

any fuel taken from living or recently living organisms

Question 4

advantages of biofuels

Answer 4

• renewable (source regrows or is continuous)
• carbon neutral (organism took in CO2 when alive)

Question 5

what is nuclear fuel

Answer 5

it takes energy from atoms nucleus
created in a nuclear power station

Question 6

what happens in a nuclear power station

Answer 6

• the uranium or plutonium fuel is in sealed cans in the core of the reactor
• nucleus is unstable so splits in 2
• energy released is transferred by a fluid (coolant) that is pumped through the core

Question 7

what happens with the coolant in a nuclear power station

Answer 7

• coolant is hot so flows through a pipe to a heat exchanger then back
• energy transferred by the coolant used to turn water into steam in the heat exchanger
• steam drives turbines that turn electricity generators

Question 8

advantages of nuclear energy

Answer 8

• produces much more energy than fossil fuels
• no greenhouse gases released, does not need to be burned

Question 9

disadvantages of nuclear power

Answer 9

• used fuel rods produce radioactive waste that needs to be stored for centuries
• a reactor explosion could release radioactive material over a large area, environmental impact, death
• uranium is a finite recourse
• expensive to build, run and decommission

Question 10

how to produce wind power

Answer 10

• using wind turbines
• winds force drives turbines blades, which turns a generator

Question 11

advantages of renewable resources (tidal power etc)

Answer 11

• renewable
• no fuel needed, so carbon free
• natural processes so infinite recourse
• used when connection to national grid is uneconomical (road signs, remote areas)

Question 12

disadvantages of wind power

Answer 12

• unreliable, depend on weather
• eyesore
• don’t generate that much

Question 13

how does wave power work

Answer 13

• a wave generator uses the waves to make a floating generator move up and down, turning a generator
• cable between generator and shoreline delivers electricity to the grid system

Question 14

disadvantages of wave power

Answer 14

• need to withstand storms
• don’t produce constant supply
• cables needed along the coast, can spoil coastline
• tidal flow patterns might change, affecting habitats of bird and marine life

Question 15

how does hydroelectric power work

Answer 15

• rainwater collected in a reservoir flows downhill
• flowing water drives turbines, turn generators

Question 16

how does tidal power work

Answer 16

• traps water from each high tide behind a barrage
• released back into the sea through turbines, driving generators in barrage
  cables to connect turbines to national grid

Question 17

how is sunlight turned into energy

Answer 17

• a solar heating panel heats water that flows through it
• a solar power tower uses thousands of flat mirrors surrounding the base to reflect sunlight onto a big tank on top of a tower
• water turned to steam on the tower by the heating effect of the solar radiation
• steam piped to ground level, turning generators
• mirrors controlled by a computer to track the sun

Question 18

advantages of solar energy

Answer 18

• useful for where small amounts of energy are needed (watches) or in remote areas
• renewable
• carbon free
• cost nothing to run

Question 19

how is geothermal energy tranferred

Answer 19

• from thermal energy from decay of radioactive substances in earth
• energy transferred from these substances heat surrounding rock
• in power stations in volcanic areas or with hot rocks under:
• water pumped down to produce steam which drive generators at ground level
• or piped directly to building to heat water and pumped around it

Question 19

disadvantages of solar energy

Answer 19

• expensive to buy
• lots needed to generate enough to be useful (takes up space)
• lots of sunlight needed to generate enough to be useful
• unreliable (clouds)

Question 20

what are the negatives of fossil fuels

Answer 20

• greenhouse gases released, accumulate, global warming
• can produce sulphur dioxide, so acid rain
• non - renewable, finite recourse

Question 20

what are the disadvantages of renewable energy

Answer 20

• not able to meet worlds demand
• wind turbines create noise pollution and are an eyesore
• tidal barrages affect river estuaries and habitats
• hydroelectric schemes need large reservoirs of water, affect animal and plant life. Habitats flooded for dams
• solar cells need to cover large areas
• unreliable, depend on conditions

Question 21

on what terms can energy recourses be evaluated

Answer 21

• reliability
• environmental effects
• pollution
• waste

Question 22

how is the variable demand for energy met

Answer 22

• using nuclear and coal fired power stations
• gas fired power stations and pumped storage schemes to meet extra demand in winter
• renewable energy when demand is low to store energy in pumped storage schemes