Renewable energy resources

Question 1

3 Properties of renewable energy resources

Answer 1

-Intermittent , so not available all the time e.g solar and wind
-Low energy density , increases amount of equipment required , but Biofuels have sightly higher energy density and could replace liquid vehicle fuels
-Low environmental impacts , try to avoid scenic and urban areas with low aesthetics e.g windfarms

Question 2

3 Problems with solar power

Answer 2

-Intermittence
-reliability
-low energy density

Question 3

2 Environmental impacts of solar panels

Answer 3

• manufacturing requires mineral extraction and toxic wastes are produces such as cadmium
  -Use impacts such as land take and water requirements for cleaning

Question 4

3 New solar power technologies

Answer 4

• Anti reflective surfaces, mimic moths cornea means more light reflects into cells than away
  -Transparent pv cells , can provide shade and reduce overheating , act as windows
  -multi junction photovoltaic , having multiple layers made of different materials that absorb different wavelengths

Question 5

3 locational constraints for HEP

Answer 5

-large water catchment area
-No serious land use conflicts
-Low seismic activity

Question 6

2 environmental impacts of HEP

Answer 6

-Reservoir creation requires large amounts of minerals such as rock and sand , it will also flood an environment destroying habitat but will also make one
-Sedimentation can increase turbidity and reduce dissolved o2 levels

Question 7

2 New HEP schemes

Answer 7

Low head , water drops a short distance
-Waterwheels , do not suffer from screen blockages from leaves and litter but are less efficient than turbines
-Micro-hydro schemes , small scale schemes , they divert part of the flow of a river to drive a turbine but do not create barrier across whole river

Large HEP , high head
water drops large distance

Question 8

2 ways of harnessing wind power

Answer 8

HAWT
-More advanced technology
-Higher efficiency than VAWTS
VAWT
-Quieter than HAWTS
-Operate at lower wind velocities

Question 9

3 locational constraints of wind power

Answer 9

-Land use conflicts
-High wind velocities
-public opposition

Question 10

2 environmental impacts of wind power

Answer 10

-Bat and bird strikes , VAWTS are seen easier so cause less deaths
-Noise

Question 11

2 new wind power technologies

Answer 11

-Blade tip fins , reduce turbulence and wind resistance increasing efficiency
-Nacelle brushes , reduce air escaping between blade base and hub which increases kinetic energy absorbed by blades

Question 12

2 new wave power technologies

Answer 12

-Point absorber , floating structure that rises and falls as waves pass and is connected to non-moving base , this movement turns a generator

-Terminator device , breaking waves force water into above sea level reservoir which then flows back to the sea turning a generator , this can be enhanced by using a sea wall to increase wave height

Question 13

3 issues with wave power

Answer 13

-Low environmental factors but manufacturing and installation
-Equipment must be able to withstand storms and corrosion
-Difficult to anchor in deep water

Question 14

2 ways to harness biofuels

Answer 14

-burning products such as wood or combustible crops
-using waste products such as methane or landfill biogas

Question 15

2 advantages of biofuels

Answer 15

-Can be stored until they are needed so supply can match demand
-Fuels themselves are carbon neutral

Question 16

2 disadvantages of biofuels

Answer 16

-Large areas of farmland required
-intensive farming technique may release nearly as much co2 as using fossil fuels

Question 17

1 new biofuel technology

Answer 17

-Hydrogen from algae , some algae produce hydrogen during photosynthesis if they are deprived of sulfur and this hydrogen can be used as fuel

Question 18

2 ways to harness geothermal power

Answer 18

-Low temperature schemes , groundwater is heated by hot rocks underground , can be used district heating
-high temperature schemes , high temperature groundwater brought to the surface using extraction borehole and steam produced can be used to generate electricity

Question 19

2 Environmental impacts of geothermal power

Answer 19

-Infrastructure such as hot water pipes can be obstacles for migrating large mammals
-Waste water may contain heavy metals

Question 20

1 new geothermal technology

Answer 20

-low temperature fluids , boiling liquids to turn turbines at low temperature , makes it more available world wide

Question 21

3 types of tidal power

Answer 21

-Barrage , whole bay
-Lagoon , only part of bay
-In stream turbines , fixed to the seabed

Question 22

2 advantages of tidal power

Answer 22

-Predictable as based around sun and moon locations
-Tidal barrage have larger electricity generation than most other renewable schemes

Question 23

2 Disadvantages of tidal power

Answer 23

-Few suitable sites
-High environmental impacts such as materials required , sedimentation