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.
The amount of energy input in a Sankey Diagram is shown at the…
…LEFT of the arrow tail and is proportional to the thickness of the arrow tail.
The sum of the widths of the NEW arrows at a split is equal to the…
width of the arrow BEFORE the split.
Each energy OUTPUT should be shown on the…
RIGHT with an arrow head.
Useful energy transfers in a Sankey Diagram flow to the…
Wasteful energy transfers flow….
Useful energy transfers in a Sankey Diagram flow to the RIGHT.
Wasteful energy transfers flow DOWN or UP.
What does the efficiency of a component tell you?
The proportion of electricity that it transfers to a useful form.
What is the equation for Efficiency?
energy USEFUL transferred / TOTAL energy supplied x 100%
As a person, how can we use less electricity? Give 5 ways.
- Using high-efficiency A-rated appliances
- Using energy-saving lightbulbs.
- Turning off components when they aren’t needed.
- Not boiling more water than is necessary and cooking food in a microwave oven.
- Installing cavity wall / loft-insulation / double glazing / fibreglass wool hot water tank jacket / thick curtains/ in houses to reduce heat loss.
As a nation, how can we use less energy? Give 3 ways.
- Using more efficient cars.
- Living in houses with better installation.
- Building more efficient power stations and improving the output of old power stations.
How can workplaces save energy? Give 3 ways.
- Appliances should be switched off when not in use.
- Not printing and photocopying things unnecessarily.
- Providing employees incentives for using energy-efficient ways to travel to work, e.g. cycling/public transport.
How can the government encourage people to save energy? Give 3 ways.
- Offering grants for better home installation.
- Running schemes to trade in old boilers for more efficient ones.
- Improving public transport.
As the population increases and the quality of life for many people improves, what will rise in the future?
The global demand for energy and other resources.
How can the impact of human activity on the environment be reduced? Give 2 ways.
- Recycling resources such as metals, glass and plastics.
2. Generating electricity from renewable sources of energy, e.g. water, wind and solar power.
Why is electricity convenient?
It is easily transmitted over long distances and can be used in many ways.
What device is used to produce mains electricity?
GENERATORS
What happens in a generator?
It contains an ELECTROMAGNET near a coil of wire. There is a voltage across the coil when the electromagnet spins.