Chapter 5 : Macrogeneration

Question 1

Outline the phases which happen between turbine, condenser and boiler. {2}

Answer 1

The steam from the turbine passes to the condenser which may be a cooling tower or lake {1}

and this changes it back to water before returning it to the boiler to be reheated {1}.

Question 2

Give one example of their use to generate electricity directly and one example of their use to generate electricity indirectly.
{2}

Answer 2

Direct : Wind, Hydroelectric, Wave or Tidal. {1}

Indirect : Solar PV or Biomass. {1}

Question 3

Renewable energy sources can be categorized into two groups, direct and indirect.
(i): Identify two direct renewable energy sources.
1. __________________ {1}
2. __________________ {1}

Answer 3

Wind, Hydroelectricity, Wave, Tidal

Question 4

ii): Explain what is meant by the term indirect renewable energy source. {2]

Answer 4

An indirect renewable source of energy will take energy from a renewable source [1]

such as the sun and using a physical
characteristic of the material being used, convert this energy into electrical energy. [1]

Question 5

Explain how a smart grid facilitates the incorporation of electricity generated from renewable sources. {3}

Answer 5

The energy produced from renewable sources varies over time. {1}

A ‘SMART’ grid systems computer measures the amount of electricity that is being produced at any point in time and then increases of decreases the amount of non-renewable that needs to be generated to meet the requirements.(1)

In doing so the ‘SMART grid’ enables the amount of pollutant / carbon dioxide produced to be minimised. {1}

Question 6

Explain the concept of a smart grid. {2}

Answer 6

A computer-controlled electricity network that switches input from one energy source to another {1} as demand for energy varies on the grid {1}

Question 7

Outline one way in which a smart grid can facilitate the efficient supply and distribution of electricity. {1}

Answer 7

• By incorporating energy generated from international energy sources {1}

Question 8

Identify another name by which Combined Heat and Power (CHP) is also known. {1}

Answer 8

Cogeneration. {1}

Question 9

Discuss the role of Combined Heat and Power in improving energy efficiencies in traditional power plants. {4}

Answer 9

Combined Heat and Power (CHP) integrates the production of usable heat and power (electricity) {1}

In one single, highly efficient process {1}

CHP generates electricity whilst also capturing usable heat that is produced in this process {1}

This contrasts with traditional ways of generating electricity where vast amounts of heat are wasted. {1}

Question 10

Discuss how CHP can improve energy efficiencies in the production of heat and power and contrast this with the processes in traditional power plants. {4}

Answer 10

Combined Heat and Power (CHP) integrates the production of usable heat and power (electricity) [1],

in one single, highly efficient process [1].

CHP generates electricity whilst also capturing usable heat that is produced in this process [1].

This contrasts with traditional ways of generating electricity where vast amounts of heat are wasted [1].