Renewable Energy

Question 1

Photothermal solar power

Answer 1

photothermal systems absorb sunlight to produce heat, usually to heat water for low-temp uses such as space heating or domestic hot water.

Question 2

Passive solar architecture

Answer 2

Buildings can be designed to maximise the absorption of sunlight for heating without the use of active working equipment.

Question 3

Photovoltaic (PV) solar power

Answer 3

When a PV cell absorbs photons of light. electrons are dislodged from atoms in the upper layer of the PV cell. The electrons provide electrical currents to power electrical appliances.

Question 4

Name new Solar Power Technologies

Answer 4

Multi Junction Photovoltaic cells
Antireflective surfaces
CSP (thermal storage)
Photovoltaic / thermal hybrid systems (PVT systems)
Transparent PV cells
Heliostats
Self-Cleaning Panels

Question 5

Describe Multi Junction Photovoltaic cells

Answer 5

Multiple layers made of different materials, each of which absorb different wavelengths of light. This means greater amount of available light is absorbed and converted to electricity.

Question 6

Describe Anti-Reflective surfaces

Answer 6

Giving PV cells a textured surface reflects lights into the cells rather than away from them. Some designs mimic moth eyes

Question 7

CSP (thermal storage)

Answer 7

Parabolic reflectors are used where light is absorbed by tubes of oil which heat molten salt in large insulated tanks. The salt is heated up to temperatures of 550C that can be used to boil water and spin steam turbine whenever electricity is required.

Question 8

Heliostats

Answer 8

Angle of a solar panel is adjustable so that it is always at the optimum angle for absorbing light

Question 9

Hydroelectric Power

Answer 9

GP of rainwater that lands upland can be harnessed as kinetic energy flowing downhill

Question 10

What are some locational constraints of harnessing HEP

Answer 10

Large water catchment area needed
High total rainfall
Rainfall turbidity impacts

Question 11

HEP impacts on a river

Answer 11

sedimentation in the river can reduce turbidity downstream and the replenishment of nutrients onto the flood plain around the river.

Question 12

New HEP technologies and explain them

Answer 12

Low Head Turbines: Waterwheels are less efficient but do not suffer from screen blockages with leaves and litter meaning less variation of flow.
Kaplan Turbines: Axial flow turbines with blades that can be rotated to allow for variations in water flow

Question 13

Wind power new technologies

Answer 13

HAWT’s
VAWT’s

Question 14

Describe VATS’s

Answer 14

vertical axis wind turbines are driven by wind from any direction. They are quieter than HAWT’s and can operate at lower wind velocities. They are however relatively new and have lower efficiency.

Question 15

Describe HAWT’s

Answer 15

Technology that is more advanced and well established. It has a higher efficiency than VAWT’s. Stress can occur on the blades and taller towers are needed for viable energy production.

Question 16

Locational constraints of wind energy

Answer 16

Ecological impacts
land requirement
telecommunication interference

Question 17

What are spring and neap tides

Answer 17

spring tides are when they are greater, neap tides are when they’re at their lowest.

Question 18

Define tidal barrages

Answer 18

Dam is built across an estuary or bay in which turbines are located so water flowing in or out over lakes flows over the turbines.

Question 19

What is a tidal lagoon

Answer 19

Surrounds a selected part of an estuary or bay.

Question 20

Wave Power

Answer 20

Vertical movement of water (kinetic energy)

Question 21

Different ways of harnessing wave power

Answer 21

Point absorbers which have floating structure which rises and falls as waves pass
Overtopping / terminating device - breaking waves force water into a storage reservoir which is above sea level. The water flows back to the sea passing through a turbine which generates electricity.