What should I already know?

In previous lessons in this unit you will have learned how to read an Energuide label as well as the financial costs to use electricity in NS. You should also have an understanding of which electrical uses are the least efficient. An example of this would be that traditional filament light bulbs are far less efficient at producing light than newer CFL light bulbs. You will also be aware of how similar technologies that use electricity have changed over time to become more efficient.