Chapter 4 and 5, Power Generation And Macrogeneration

Question 1

Name all 9 energy types.

Answer 1

-Kinetic energy

-Thermal energy

-Gpe

-Chemical energy

-Sound energy

-Electrical energy

-Elastic potential energy

-Nuclear

-Radiant

Question 2

State the law of conservation.

Answer 2

Total energy in= Total energy out

Question 3

What is the definition of conservation of energy?

Answer 3

Energy cannot be created or destroyed, merely transformed from one form to another.

Question 4

By what year does the U.K. plan to phase out coal and why?

Answer 4

2025, it is very polluting and it isn’t a clean fossil fuel like gas.

Question 5

Identify the 4 stages of generation of electricity in a fossil fuel power plant.

Answer 5

-Stage 1, Combustion of fossil fuels

-Stage 2, Evaporation of water

-Stage 3, Steam used to turn turbine

-Stage 4, Condensing in the cooling tower.

Question 6

How efficient are traditional power plants and where is the bull of the energy being wasted?

Answer 6

They are in around 40% efficient, the majority of the energy is being wasted in the cooling tower.

Question 7

List 4 direct sources of renewable energy.

Answer 7

Wind, Hydroelectric, Wave and Tidal.

Question 8

Name 2 indirect sources of renewable energy.

Answer 8

Solar PV or Biomass.

Question 9

Show the process of electrical energy generation in a wind turbine. Identify the energy loses.

Answer 9

KE of wind>KE of blades and main shaft>KE of high speed shaft>Electrical Energy in generator. Thermal and sound energy loses throughout.

Question 10

Show the process of electrical energy generation in a Solar PV panel. Identify energy loses.

Answer 10

Radiant energy from sun> PV panels generating Electrical Energy. Thermal loses throughout.

Question 11

Show the process of electrical energy generation in a Hydroelectric Dam. Identify energy loses.

Answer 11

Gpe of water in dam> KE of moving water> KE in turbine> Electrical Energy in generator. Thermal and sound loses throughout.

Question 12

Show the process of electrical energy generation via Tidal generation. Identify energy loses.

Answer 12

Gpe of water behind Tidal wall>KE of moving water> KE of turbine> Electrical Energy in generatior. Thermal and sound loses throughout.

Question 13

Show the process of electrical energy generation via Wave generation. Identify energy loses

Answer 13

Radiant energy from the sun> KE from the wind and waves> KE in wave generator> Electrical Energy in generator. Thermal and sound loses throughout.

Question 14

Show the process of electrical energy generation via biomass. Identify energy loses

Answer 14

Chemical energy in biomass>burning of fuel releasing thermal energy>thermal and kinetic energy of steam> KE in turbine> Electrical Energy in generator. Thermal loses throughout.

Question 15

What is the Voltage;

In the power station?

In electrical transmission lines?

In a factory?

In a house?

Answer 15

Power station= 22kv
(Step up transformer)
Transmission lines=275-400kv
(Step down transformer)
Factory=33kv
House=240v

Question 16

Why is the voltage increased in the transmission lines?

Answer 16

The huge increase in voltage results in a huge decrease in current. This minimises the heat losses occurring in the cables along the national grid.

Question 17

How much do renewables contribute to the overall electricity generation in NI.

Answer 17

In around 44% as of June 2019.

Question 18

What is a smart grid?

Answer 18

A computer-controlled electricity network that switches input from one energy source to another as demand for energy rises on the grid.

Question 19

Why are natural gas power stations the most common?

Answer 19

They can quickly adapt output to the required values. Some gas power stations are fully operational from shut down in a matter of minutes.

Question 20

What are the benefits SMART Grid?

Answer 20

-Maximise renewables

-Minimise fossil fuels

-Control electricity demand

Question 21

What is an Interconnector?

Answer 21

An interconnector is simply an electrical cable joining two nations together, it facilitates exporting energy in either direction.

Question 22

What are the environmental benefits of Interconnectors?

Answer 22

-Electrical energy from renewables from one nation can be exported to other nations when production exceeds demand.

-Connections to nations such as Norway facilities storage of renewable energy by means of pumped hydro.

Question 23

What are the Economic benefits of Interconectors?

Answer 23

-Bigger market means more competition that will drive down costs for consumers.

-Nations will have more fuel security and will be less reliant on volatile fuel prices.

Question 24

Identify and describe the characteristic of two Interconnectors joining the island of Ireland and Great Britain?

Answer 24

The EirGrid and Moyle connect NI and Ireland and are both capable of transferring 500MW of power each.

Question 25

What does CHP stand for?

Answer 25

Combined Heat and Power.

Question 26

State another name for CHP.

Answer 26

Cogeneration.

Question 27

What are the disadvantages of traditional power plants and their typical efficiencies?

Answer 27

Vast amounts of energy are lost in the cooling towers. This wasted energy limits the efficiency of the overall process to around 40%.

Question 28

How does CHP differ from traditional power plants?

Answer 28

CHP seeks to increase the effectiveness of the overall electricity production process, it does this by making use of the thermal energy that is usually lost in the steam in the cooling towers.

Question 29

What are the advantages of CHP?

Answer 29

-The efficiency of the overall process can exceed 80%.

-CHP is usually located close by to the end user so transmission losses are reduced.

-Carbon emissions are reduced as less fossil fuels are required.

-Energy bills can be minimised for customers.