Welcome to practical physicsPracticle physics - practical activities designed for use in the classroom with 11 to 19 year olds
 

Energy sources (generating electricity)

In discussing energy sources in everyday life, mains electricity is almost certain to come up. At an introductory stage, it is acceptable to call mains electricity an energy source. 
 
In fact it is a ‘secondary’ source, which has to be generated using a ‘primary’ energy source (such as a fossil fuel or nuclear fuel). This is important to any discussion of the greenhouse effect or global warming. 
 
Discussion of ‘energy sources’ for generating electricity might lead on to so-called ‘renewable’ sources such as wind, sunlight and waves. ‘Wind energy’ and ‘solar energy’ are in everyday use. This broadens the idea of an energy source to include the idea that something moving (like the wind) or a steady beam of radiation (such as sunlight), can be an energy source. 
 
‘Save it’ 
The approach described above provides a good platform for later discussions of energy saving, especially domestic saving. There are good resources for making simple estimates of, for example, the rate of energy loss through insulated and non-insulated roofs. Also useful would be comparisons of the energy needed to heat water for a bath or a shower. 
 
Electricity is the one case where quantities are known by common knowledge through powers of appliances. And calculations are easy, energy = power x time. 
 
For example, Gerneration Green offers some good ideas and teaching resources. 

Related guidance

Power and energy