Microgeneration Flashcards
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 microelecricity technologies
Solar PV
Wind
Identify two of the main benefits of home community microgeneration of electricity
Reduced energy costs
Contribution to environmental targets
Enhanced security of supply
Financial incentives
Explain how heat pump technology raises the heat energy from the ground to be level suitable for domestic heating process. You should refer only to the evaporator and compressor
Heat energy is absorbed from the ground in a collector loop
In the evaporator this heat causes a refrigerant to become gaseous
The pressure of the heat 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
The gas is pumped through a compressor which raises its temperature
The gas turns back to a liquid in the heat exchanger/condenser
Transferring it’s heat to the heated circuit of the house
A domestic heat pump has a Coefficient of Performance of 3.5. Explain what this means
A coefficient of performance is a measure of the efficiency of a heat pump
It is the ratio of he energy output from the pump to the amount of energy required to operate the pump.
If the heat pump uses up 3.6MJ in one hour, what is the heat output in this time?
Coefficient of performance= heat produced by heat pump/energy consumed by heat pump
3.5=heat produced/3.6MJ
Heat produced= 3.5 x 3.6 MJ
= 12.6MJ
A heat pump has a COP of 2.8. The heat pump produces 16.8MJ of heat in one hour. State clearly the formula for the COP of a heat pump and calculate the amount of energy it will use in one hour
COP = energy output from heat pump/energy used by heat pump
2.8 = 16.8MJ/energy used
Energy used = 16.8MJ/2.8 = 6MJ
Renewable sources are used in conjunction with micro heat technologies. One of these technologies is a ground source heat pump
Pond type heat pump
