Describe how useful energy may be obtained, or electrical power generated, from: (a) chemical energy stored in fossil fuels (b) chemical energy stored in biofuels (c) hydroelectric resources (d) solar radiation (e) nuclear fuel (f) geothermal resources (g) wind (h) tides (i) waves in the sea including references to a boiler, turbine and generator where they are used

Define the kilowatt-hour (kWh) and calculate the cost of using electrical appliances where the energy unit is the kWh

Define power as work done per unit time and also as energy transferred per unit time; recall and use the equations (a) power = work done / time taken, P = W/t (b) power = energy transferred / time taken, P = ΔE/t