Topic 1 - Energy resources

Question 1

What are non-renewable energy sources?

Answer 1

• fossil fuels and nuclear fuel
• they will eventually run out

Question 2

What are fossil fuels?

Answer 2

• natural resources that form underground over millions of years
• typically burnt to provide energy
• three main ones are: coal, oil, natural gas
• they will all run out one day and all do damage to environment, but are all reliable

Question 3

What are examples of renewable energy resources?

Answer 3

• the sun
• wind
• water waves
• HEP
• bio-fuel
• tides
• geothermal

Question 4

What are renewable energy sources?

Answer 4

• resources that will never run out
• dont provide as much energy - some unreliable as they rely on weather

Question 5

Wind power?

Answer 5

• each turbine has generator inside - rotating blades turn generator - produce electricity
• no pollution
• spoil view - 1500 wind turbines required to replace one coal-fired power station
• very noisy
• problems when wind stops/when wind is too strong - impossible to increase supply when extra demand - on average wind turbines produce energy 70-85% of the time
• intital costs quite high - no fuel costs/minimal running costs
• no permanent damage to landscape

Question 6

Solar cells?

Answer 6

• generate electric currents directly from sunlight
• no pollution
• very reliable source in sunny countries - only in daytime
• cant increase power output when extra demand
• initial costs high - after that energy is free and running costs are very low

Question 7

Geothermal power?

Answer 7

• source of energy is slow decay of various radioactive elements deep inside earth
• reliable - very little damage to environment
• can generate electricity or heat buildings directly
• arent very many suitable locations - cost of building power plant very high compared to energy produced

Question 8

HEP?

Answer 8

• requires flooding of valley by building big dam - water allowed out through turbines - no pollution
• big impact on environment due to flooding of valley (rotting vegetation releases methane) - loss of habitat
• provides immediate response to increased demand
• no problem with reliability except times of drought
• initial costs high - no fuel costs/minimal runnings costs

Question 9

Wave power?

Answer 9

• lots of wave-powerd turbines around the coast - moving turbines connected to generator
• no pollution - distrubs seabed and habitats of marine animals - spoils view - hazardous to boats
• fairly unreliable - waves die out when wind drops
• intial costs high - no fuel costs/minimal runnings costs

Question 10

Bio-fuels?

Answer 10

• renewable energy resources from either plant products or animal dung - burnt to produce electricity
• fairly reliable - crops take relatively short time to grow - cannot respond to immediate energy demands
• cost to refine bio-fuels very high
• large areas of forest cleared to make room to grow bio-fuels - loss of habitat - decay/burning of vegetation releases methane and CO2

Question 11

Tidal barrages?

Answer 11

• big dams built across river estuaries - turbines in them - as tide comes in, fills up estuary and turbines
• no pollution - prevent free access by boats - spoil view - alter habitat of wildlife
• reliable - happen twice a day without fail
• initial costs moderately high - no fuel costs/minimal running costs

Question 12

Why are non-renewables reliable?

Answer 12

• enough fossil and nuclear fuels to meet current demand - extracted from earth at fast rates to always have full stock
• can quickly change to demand
• fuels slowly running out - some may run out within a hundred years
• very cost effective way to produce energy

Question 13

Why do non-renwables create environmental problems?

Answer 13

• coal, oil, gas - release CO2 into atmosphere when burned - enhanced greenhouse effect - global warming
• burning coal and oil - sulphur dioxide - causes acid rain
• oil spillages severe problems to environment
• nuclear waste dangerous - difficult to dispose of
• risk of major catastrophe like Chernobyl