Chapter 9 - Energy resources

Question 1

what is geothermal power ?

Answer 1

Type of renewable energy taken from the Earth’s core or below the earths surface

Question 2

what is the technical definition of geothermal power, in terms of below the earths surface ?

Answer 2

radioactive decay of isotopes (eg. uranium) in mantle releases heat which can be exploited for many things

Question 3

what are 2 types of low temperature schemes for harnessing geothermal power ?

Answer 3

1. geothermal springs
2. geothermal aquifers

Question 4

what are 2 types of high temperature schemes for harnessing geothermal power ?

Answer 4

1. geothermal steam system
2. hot dry rock system

Question 5

what is a geothermal spring ?

Answer 5

groundwater is heated by hot rocks

Question 6

what is a geothermal aquifer ?

Answer 6

Hot groundwater pumped from aquifer to surface

Question 7

what is a geothermal steam system ?

Answer 7

Groundwater at high temps extracted using boreholes producing high temp steam that can generate electricity

Question 8

what is hot dry rock system ?

Answer 8

Hot rocks near the surface but have no groundwater nearby to heat, to boreholes are used, water pumped down one borehole and hot steam is collected out of the other borehole

Question 9

what is the local constraint of geothermal power ?

Answer 9

geothermal power stations use terbines that need a very high heat source and therefore need recent volcanic activity so the hot rocks are near the surface, if hot rocks are too deep in the ground drilling them in uneconomic

Question 10

what are 3 environmental impacts of geothermal power ?

Answer 10

1. infrastructure - steam and pipes can provide obstacles to movement of large mammals
2. gaseous emissions - releasing this hot water can release small amounts of gas (eg. CO2 etc)
3. waste water - contains salts and heavy metals

Question 11

the new geothermal technology, low temperature fluids, what are different about these ?

Answer 11

they require lower temperature liquids to turn the turbines and create energy

Question 12

3 examples of energy uses within agriculture and fisheries

Answer 12

1. fuel for machinery like tractors / combine harvestors
2. manufacture for chemicals like fertilisers
3. food processing like sugar refining

Question 13

3 examples of energy uses within ‘other industries’

Answer 13

1. machinery operation like rock crushing
2. heat for baking like pottery
3. sewage treatment

Question 14

3 examples of energy uses within domestic energy use

Answer 14

1. space heating
2. lighting
3. running appliances like fridges

Question 15

2 examples of energy uses within transport

Answer 15

1. transport of goods - trains, trucks etc
2. transport of people - cars, buses etc

Question 16

what are the features of energy resources (15)

Answer 16

• renewable / non-renewable
• depletable / non-depletable
• abundance
• local constraints
• intermittency
• predictability
• energy density
• resource availability
• need for conversions to increase usefulness
• applicability to specific uses
• ease of storage
• ease of transportation
• environmental impacts
• technological development
• political / economic influences

Question 17

what is meant by renewable and non-renewable energy sources ?

Answer 17

• renewable = naturally forms, reforms relatively quickly therefore infinite resource
• non-renewable = not being formed or reform so slow that current use > reform speed

Question 18

what is meant by depletable and non-depletable energy resources ?

Answer 18

• Depleteable = use can reduce future availability
• non-depletable = the opposite

Question 19

what is meant by an abundance in energy resources ?

Answer 19

• ensures there is enough of the resource that exsists

Question 20

what are 3 things that affect the abundance of an energy resource that isnt it ‘just not exsisting’ ?

Answer 20

• fossil fuels deep upderground so cant extract
• winds too high above the ground and cant make aerogenerators that tall
• wave power to far from the coast therefore water too deep for anchor equipment

Question 21

what are 3 things influencing energy resources in terms of local constraints ?

Answer 21

1. energy resources are not evenly distributed - all have locational factors
2. sources that can only be accessed via extraction may be located in favourable deposits
3. sources that harness natural processes may depend on regional / local features (eg. climate / topography)

Question 22

whats a local constraint of fossil fuels / what do power stations require access to

Answer 22

• fuel supplies
• suitable construction sites
• condenser cooling water (lake etc)

Question 23

whats a local constraint of nuclear power / what do power stations require access to

Answer 23

• condensor cooling water (lake etc)
• suitable constructin site

Question 24

whats 2 local constraint of solar power

Answer 24

• high light intensity
• low cloud cover

Question 25

whats a local constraint of wind power ?

Answer 25

• area with strong, reliable winds (open plains etc)
• areas with low land conflicts

Question 26

whats a local constraint of wave power ?

Answer 26

• strong reliable winds over water
• reliable prevailing wind direction
• long fetch (stretch of water over whcih the wind blows)

Question 27

whats a local constraint of hydroelectric power (HEP)

Answer 27

• high reliable rainfall
• large catchment
• impermeable bedrock
• stable geology

Question 28

whats a local constraint of biofuels ?

Answer 28

• nearby forest areas
• farmland for biofuels / crop or livestock waste
• nearby urban area

Question 29

whats a local constraint of geothermal power ?

Answer 29

• hot rocks near the ground surface
• recent volcanic activity

Question 30

whats a local constraint of tidal power ?

Answer 30

• tidal range is large
• coastal features that focus tidal flow to increase flow velocity or tidal range

Question 31

what is meant by intermittency in energy resources ?

Answer 31

If energy resource is not available at times then its hard to rely on it

Question 32

what is meant by predictability in energy resources ?

Answer 32

To know how much energy will be available and whether it will meet demand for energy

Question 33

what is meant by energy density in energy resources ?

Answer 33

measure of the amount of energy in a given amss of energy resource

Question 34

what energy density is most useful and why ?

Answer 34

High energy density becuase :
- smaller quantities needed ∴ storage + transport is easier
- easier to reach high temperatures