Question

give an example of an energy conversion

Answer 1

http://en.wikipedia.org/wiki/Hydropower

Answer 2

"give an example of an energy conversion"
We have not yet found a counter-example to the Principle of Conservation of Energy.
So take any random process, it will turn out to be an example of energy conservation. ;)

Answer 3

Example is I.C engine i.e. the engine of motorcycle
here petrol-chemical energy changes to mechanical work
another example is nuclear fusion or fission here some mass is directly converted to energy by law E=mc^2