P3 - energy resources

Question 1

where does most of our energy come from

Answer 1

burning fossil fuels

Question 2

how do coal or oil fired power stations work

Answer 2

burning fuel heats water in a boiler, this produces steam, the steam drives a turbine that turns an electricity generator

Question 3

what is a biofuel

Answer 3

any fuel taken from living or recently living organisms

Question 4

how is a biofuel renewable

Answer 4

it’s biological source either regrows or is continuously produced

Question 5

how is a biofuel carbon neutral

Answer 5

the carbon the living organism takes in from the atmosphere can balance the amount that is released when it is burnt

Question 6

what is the fuel used in a nuclear power at station

Answer 6

uranium
plutonium

Question 7

how does a nuclear power station work

Answer 7

the uranium atoms nucleus splits in two, energy is transferred from nucleus, core becomes hot, energy of core is transferred by coolant, coolant flowed through pipe to heat exchanger then back to reactor core, energy transferred is used to turn water into steam which drives turbines

Question 8

how does wind power work

Answer 8

wind drives turbines blades, this turns a generator, power generated increases as wind speed increases

Question 9

how does wave power work

Answer 9

waves move a floating generator up and down, turns the generator

Question 10

how does hydroelectric power work

Answer 10

rainwater collected in a reservoir flows down hill, flowing water drives turbines that turn electricity generators at the bottom of the hill

Question 11

how does tidal power work

Answer 11

traps water from high tide behind barrage, water released into sea through turbines, turbines turn a generator

Question 12

what is the physical distributor of all energy in UK

Answer 12

the national grid

Question 13

when are solar panels useful

Answer 13

when only small amounts of electricity are needed
or in remote places

Question 14

what are the disadvantages of solar panels

Answer 14

very expensive to buy (cost nothing to run though so every cloud)
lots are needed to generate enough power to be useful

Question 15

how does a solar power tower work

Answer 15

thousands of mirrors reflect sunlight onto big water tank
water is turned to steam by heating effect of solar radiatiation
steak is piped to ground level where it turns electricity generators

Question 16

how does geothermal energy work

Answer 16

energy is released by radioactive substances
energy transferred from these radioactive substances heat the surrounding rock
energy is transferred by heating towards the earths surface

Question 17

what are the issues with fossil fuels

Answer 17

greenhouse gases get released, warming the atmosphere
produce sulfur dioxide which causes acid rain
non renewable

Question 18

advantages of nuclear power

Answer 18

no greenhouse gases emitted
more energy is transferred from each kg of uranium/plutonium

Question 19

disadvantages of nuclear power

Answer 19

used fuel rods contain radioactive waste which has to be stored safely for centuries
if a reactor explodes radioactive material would spread over a wide area

Question 20

advantages of renewable energy sources

Answer 20

never run out
do not produce greenhouse gases
do not create radioactive waste
can be used where connection to national grid is uneconomical

Question 21

disadvantages of renewable energy sources

Answer 21

not able to meet world demand for energy
wind turbines create a whining noise + are unsightly
tidal barrages affect habitats of creatures and plants
reservoirs for hydroelectric schemes can affect plant and animal life
solar cells need to cover large areas
unreliable

Question 22

what are the reliability issues with hydroelectric, wind/waves, tidal, and solar power

Answer 22

hydroelectric - upland reservoirs could run dry
wind/waves - too weak on calm days
tidal - height of tide varies
solar - no solar energy at night, variable during day

Question 23

how is the demand for electricity met (x4)

Answer 23

using nuclear and coal power stations to provide constant amount
gas fired power station and pumped storage schemes for daily variations in demand
using renewable sources when demand is high and when conditions are suitable
using renewable sources when demand is low to store energy is pumped storage schemes

Question 24

what energy source is capital cost lowest for

Answer 24

gas fired power stations

Question 25

what energy source is capital cost greatest for

Answer 25

wind power and nuclear power (including decommissioning cost)

Question 26

what are overall costs lowest for

Answer 26

hydroelectricity

Question 27

what are overall costs highest for

Answer 27

offshore wind farms