1.6 MICROGENERATION Flashcards
(19 cards)
Define the term microgeneration
Small scale generation of heat and power.
Microgeneration is defined as the small-scale
generation of heat and power. Identify two micro-electricity technologies.
Solar PV
Wind
Identify the two main sources of renewable
microgeneration in microelectricity technologies
Solar Pv
Wind
Name two micro electricity technologies and two micro heat technologies.
Micro electricity technologies
Microelectricity: Solar PV
Wind Turbines
Name two micro electricity technologies and two micro heat technologies.
Micro heat technologies
Microheat:
Biomass, Solar thermal, Ground source heat pump
Identify two of the main benefits of home or community microgeneration of electricity
Reduced energy costs.
• Contribution to environmental targets.
• Enhanced security of supply.
• Financial incentives
Identify two economic benefits and two environmental benefits for the school if
they choose to install a ground source heat pump.
Economic benefits:
Lower heating bills for the school
Benefit from government incentives, e.g. Renewable Heat Incentive
Identify two economic benefits and two environmental benefits for the school if
they choose to install a ground source heat pump.
Environmental benefits:
Does not burn fossil fuels as a fuel source, therefore doesn’t produce
carbon dioxide on site
• Deliveries of heating fuel are no longer necessary
• Does not require any fuel to be mined from the earth, therefore has a
less detrimental effect on the environment
Discuss three different benefits of community microgeneration with reference to a ground source heat pump.
Reduces reliance on fossil fuels. Using a ground source heat pump
will provide heating for the house, therefore replacing the need to use fossil
fuels for heating.
• Reduces heating bill. The heat from the sun replaces the need to
purchase heating fuel.
• Makes a contribution towards environmental targets.
Explain how heat pump technology raises the heat energy from the ground to a
level suitable for domestic heating purposes. You should refer only to the evaporator and compressor.
Heat energy is absorbed from the ground in a collector loop. {1}
In the evaporator this heat causes a refrigerant to become gaseous. {1}
The pressure of the gas is raised in the compressor, this causes the
temperature to be increased to a level which is useable for domestic purposes
With reference to the roles played by the evaporator, compressor and
condenser, describe how the application of heat pump technology in the figure
below extracts low grade heat from the outside air and converts it to high grade
heat suitable for domestic heating and hot water.
Heat from the outside air causes the refrigerant to turn into a gas in the
evaporator.
This gas is pumped through a compressor which raises its temperature.
The gas turns back to a liquid in the heat exchanger / condenser.
Transferring its heat to the heating circuit of the hous
Explain the role of the following parts of a ground source heat pump: evaporator
Evaporator – In the evaporator heat is transferred from the ground loop into the
refrigerant. [1] The refrigerant boils and evaporates (even at a low temperature)
thus storing the generated energy in its gaseous form
Explain the role of the following parts of a ground source heat pump: compressor
Compressor – The gas from the evaporator is compressed to increase its
pressure. [1] This increases the temperature of the refrigeran
Explain the role of the following parts of a ground source heat pump: condenser
Condenser – The condenser acts as a heat exchanger where heat is
transferred to the heating system of the house. This cools the refrigerant
again
Explain the role of the following parts of a ground source heat pump: expansion value
Expansion Valve – The refrigerant passes through the expansion valve
reducing its pressure and temperature. [1] The refrigerant returns to the
evaporator where the process begins again
domestic heat pump has a Coefficient of Performance of 3.5. Explain what is
meant by a Coefficient of Performance
A coefficient of Performance is a measure of the efficiency of a heat pump.
It is the ratio of the energy output from the pump (energy out) to the amount of
energy required to operate the pump (energy in)
Coefficient of performance (COP) formula
Heat produced by heat pump/ energy consumed by heat pump
The school is located in a busy town and has a limited amount of space.
Discuss what type of ground loop would be best for the school’s ground source
heat pump
A vertical ground loop is the best option for the school. This is because there is
only enough available space to bore down vertically into the ground.
Name all 3 types of looped ground source heat pump
Vertical
Horizontal
Pond
