P3 - Sustainable energy Flashcards
What are the 6 types of primary energy sources?
- Fossil fuels (coal, oil, gas)
- Nuclear fuel (uranium and plutonium)
- Biofuels (plants and animals)
- Wind
- Waves
- Sunlight (radiation from the Sun)
What can primary energy sources transfer their energy to?
Secondary energy sources, e.g. electricity
Why is electricity a secondary energy source?
It is produced using other energy sources.
What are fossils fuels known as?
Non-renewable energy source (one day they will run out)
What does the burning of fossil fuels increase?
The amount of Carbon Dioxide which is a greenhouse gas
What does the Greenhouse Effect (caused by CO2) contribute to?
GLOBAL WARMING: an increase in the temperature of the Earth’s surface
What does global warming result in?
Climate Change - leading to floods and storms
What is Power?
The amount of energy transferred in one second
i.e. the rate of energy transfer
A power of one Watt (W) transfers…?
One JOULE of energy in one second.
How do you calculate the transfer of energy?
Energy transferred (J / kWh) = Power (W / kW) x Time (s/h) E = P x t
Why does Domestic electricity measure energy in transfer in kilowatt-hours (kWh) rather than Joules (J)?
A joule is a very small amount of energy.
It would be ridiculous to write down large numbers in Joules.
What is Current?
What is current measured in?
The flow of electricity in a circuit.
It’s measured in AMPERES.
What is Voltage of a power supply measured in?
Volts (V)
What does ELECTRIC current in an appliance do?
Transfers energy to it from the power supply.
What is the equation for calculating Electrical power?
Electrical power (W) = Current (A) x Voltage (V)
What is the power of an electrical device the rate of?
How is this normally given as?
The rate at which it transfers energy from the power supply.
This is normally given as a rating.
What is the formula for APPLIANCE current?
Appliance current (A) = Appliance power (W) / Supply voltage (V)
What does current in a COMPONENT transfer?
Electrical Energy into other useful forms
What does current in the connecting wires transfer?
It WASTEFULLY transfers electrical energy to heat.
What is the formula to calculate the electricity supplied to a component?
Electricity supplied to a component (in Units) = Power (kW) x Time (hrs)
What is for the formula to calculate the cost of electricity?
Cost of electricity = number of units supplied x cost per unit
What are 3 ways in which information about energy use can be displayed?
- a PIE CHART to compare different uses of electricity
- a BAR CHART to show the amount of electricity used by different components
- a LINE GRAPH to show how the number of units consumed changes with time.
What do Sankey Diagrams show?
The energy transfers in a component.
The sum of the energy transfers OUT of a component equals the….
What does this statement show?
The sum of the energy transfers OUT of a component equals the INPUT ENERGY.
This statement shows that energy is CONSERVED.