Question:How many ways are there to generate electricity?
There are only really three ways to generate useful electricity.
Other effects may produce electricity, but they cannot really be used to supply energy to homes or devices Eg Lightening.
1. The electrochemical cell. (AKA A cell or a battery.)
2. A photodiode. (AKA Solarcell or Photocell.)
3. A Generator. (AKA A dynamo.)