7 How many did you get?1. Furnace and boiler. Heats water to produce steam2. Turbine. Steam drives the turbine which is coupled to the generator.3. Generator. Produces the electricity.4. Transformer.
8 GeneratorGenerators produce a voltage across a coil of wire by spinning a magnet near it.
9 The graph shows that the demand for energy is increasing. But why?
10 Increasing energy demand. Growing world populationImproving standard of living
11 What is nuclear fuel?A nuclear fuel is one where the energy is released from changes in the nucleus.A common nuclear fuel is uranium.Refined uranium.Uranium containing ore.
12 Nuclear Power Station.The only difference between a nuclear power station and aconventional power station is how the water is heated.Why is there a concreteshield around the reactor core?
13 A downside to nuclear energy. Nuclear power stations produce radioactive waste.What do you understand by the term radioactive?
14 Radioactive.When a substance emits (gives out) ionising radiation all the time it is called radioactive.Ionising radiation can damage living cells.
15 Ionising and non-ionising. Sort the different types of radiation into ionising and non-ionising.Why is ionising radiation more dangerous than non-ionising?
16 Why is ionising radiation dangerous? Ionising radiation can damage living cells.This can lead to cancer.
17 Irradiated food. What do you notice about the strawberries that This is the sign for irradiated food.What do you notice about the strawberries thathave been irradiated?
18 Irradiation and contamination. Contamination – when the radioactive source enters the body or gets on skin or clothesIrradiation – exposure to a radioactive source outside the body.Which is more dangerous, irradiation or contamination and can you explain why? (Use the definitions above to help you).
19 PowerWhen an electric current is passed through a device electric current is transferred from the supply to the device. The rate at which this energy is transferred is called POWER. Power is measured in WATTS (W).
20 Calculating the energy transferred To calculate the energy transferred use the following equation;Energy transferred (J) = Power (W) x time (s)Question –An electric kettle connected to the 230 V mains supply draws a current of 10 A. CalculateA) The power of the kettle.B) The energy transferred in 1 minute
21 Joules and Kilojoules There are a 1000 J in 1 kJ. Convert the following joules into kJ3000 J25000 J500 J
22 The Kilowatt HourThe energy transferred when a power of 1kilowatt (1000W) is used for 1hour.
23 The kilowatt hour (kWh) = 1000W x (60 x 60s) = J Why do energy companies use kWh instead of joules to measure your electricity?
24 Kilowatt-hourThe kilowatt-hour is a unit of energy and is calculated by:Energy transferred = power x time(in kW h) (in kW) (in hours)
25 ExampleA kettle has a power rating of 1000W it is used for 3 hours a day.How much energy is transferred in one day?
26 How much does your electricity cost? N power supplies electricity in kilowatt-hours called a unit. Each unit costs 7p.A typical family uses 10kWhr a day:How much does it cost them a day?10KWhrs = 10 units10 units x 7p = 70pIt costs the family 70p a day for their electricity
27 Energy cost OR Power (KW) x time (hours) x cost per unit Energy used (KWhr) x cost per unit = total energy costORPower (KW) x time (hours) x cost per unit
28 Sankey DiagramSankey diagrams show where the energy goes.
29 Interpreting a Sankey Diagram. What do thedifferentdirection ofthe arrows tellyou about theenergy efficiency?
30 Sankey DiagramThe thickness of each arrow is drawn to scale to show the amount of energy
31 Conservation of energy What do you notice about the total amount of energy before and the total amount of energy after?Explain what conservation of energy means?
32 EfficiencyAlthough the total energy out is the same, not all of it is useful.
33 EfficiencyEfficiency is how well it transfers the energy you put in to useful energy. The efficiency of ‘something’ can be worked out by: Useful energy output x 100% Total energy input
34 Starter:What factors need to be considered when choosing an energy source?
35 Choosing and energy source. What factors need to be considered when choosing an energy source?A) Environmental impact.B) Economics.C) Waste produced.D) Carbon dioxide emissions.