Chapter5 LO 1-8 Flashcards
(11 cards)
Renewable energy sources can be used to generate electricity either directly or indirectly. Give one example of their use to generate electricity directly and one example of their use to generate electricity indirectly.
{2}
Direct use One from Wind, Hydroelectric, Wave or Tidal. {1}
Indirect use One from Solar Photovoltaic or Biomass. {1}
Renewable energy sources can be categorized into two groups, direct and indirect.
(i): Identify two direct renewable energy sources.
Any two of the following:
Wind, Hydroelectricity, Wave, Tidal
Explain what is meant by the term indirect renewable energy source. {2]
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]
Identify the main energy transformations that take place in a wind turbine. {2}
Kinetic energy transferred from the shaft (connected from the rotor, through gearbox, to the generator), to relative rotational motion (kinetic energy) between a metal coil and a magnetic field in the generator. {1}
This results in electromagnetic induction. On other words kinetic energy of relative motion is transferred into inducted electrical energy. {1}
Describe how electricity is distrubuted through the National Grid. {5}
Power stations generate electricity at 22kV {1}
This is stepped up to high voltage (275 kV or 400 kV) by transformers. {1}
Electricity is transmitted at high voltage to reduce energy losses in wires. {1}
Voltage is stepped down by transformers close to consumers. {1}
Electricity is distributed to homes at 240V. {1}
Explain how a smart grid facilitates the incorporation of electricity generated from renewable sources. {3}
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}
Explain the concept of a smart grid. {2}
A computer-controlled electricity network that switches input from one energy source to another {1} as demand for energy varies on the grid {1}
Outline one way in which a smart grid can facilitate the efficient supply and distribution of electricity. {1}
Any one from;
• By using a network of intelligent meters located throughout the grid to accurately predict demand {1}
• By incorporating electricity generated by a wide range of energy sources, including renewables, in order to meet demand {1}
• By incorporating energy generated from international energy sources {1}
Identify another name by which Combined Heat and Power (CHP) is also known. {1}
Cogeneration
Discuss the role of Combined Heat and Power in improving energy efficiencies in traditional power plants. {4}
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}
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}
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]
