1.5 MACROGENERATION Flashcards
outline the phases which happen between turbine, condenser and boiler
The steam from the turbine passes to the condenser which may be a cooling
tower or lake and this changes it back to water before returning it to the
boiler to be reheated
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
Direct use One from Wind, Hydroelectric, Wave or Tidal.
Indirect use One from Solar Photovoltaic or Biomass
Renewable energy sources can be categorized into two groups, direct and
indirect. Identify two direct renewable energy sources.
(i): Any two of the following:
Wind, Hydroelectricity, Wave, Tidal
All relevant, valid responses will be given credit
(ii): Explain what is meant by the term indirect renewable energy source.
An indirect renewable source of energy will take energy from a renewable source such as the sun and using a physical characteristic of the material being used, convert this energy into electrical energy.
Identify the main energy transformations that take place in
the wind turbine
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.
This results in electromagnetic induction. On other words kinetic energy of
relative motion is transferred into inducted electrical energy
With reference to Fig. 1 describe how electricity is distrubuted through the
National Grid.
Power stations generate electricity at 22kV
This is stepped up to high voltage (275 kV or 400 kV) by transformers.
Electricity is transmitted at high voltage to reduce energy losses in wires.
Voltage is stepped down by transformers close to consumers.
Electricity is distributed to homes at 240V.
Using the information in the figure below, explain
how a smart grid facilitates the incorporation of electricity generated from
renewable sources
The energy produced from renewable sources varies over time.
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.
In doing so the ‘SMART grid’ enables the amount of pollutant / carbon dioxide
produced to be minimised.
Explain the concept of a smart grid
A computer-controlled electricity network that switches input from one energy
source to another as demand for energy varies on the grid
Outline one way in which a smart grid can facilitate
the efficient supply and distribution of electricity
By using a network of intelligent meters located throughout the grid to
accurately predict demand
• By incorporating electricity generated by a wide range of energy sources,
including renewables, in order to meet demand
• By incorporating energy generated from international energy source
Discuss the role of Combined Heat and Power in improving
energy efficiencies in traditional power plants.
Combined Heat and Power (CHP) integrates the production of usable heat and
power (electricity)
In one single, highly efficient process
CHP generates electricity whilst also capturing usable heat that is produced in
this process
This contrasts with traditional ways of generating electricity where vast amounts
of heat are wasted.
State another name by which Combined Heat and Power (CHP) is also known
Cogeneration
Discuss how CHP can improve energy efficiencies in the productionof heat and
power and contrast this with the processes in traditional power plants.
Combined Heat and Power (CHP) integrates the production of usable heat and
power (electricity), in one single, highly efficient process. CHP generates
electricity whilst also capturing usable heat that is produced in this process.
This contrasts with traditional ways of generating electricity where vast amounts
of heat are wasted.
