What are the advantages of Heat Engine over windmill and water mill?

The main advantages of heat engine over windmill and water mill are given below:

1. A heat engine can be used anywhere but a wind mill can be used only where wind is blowing and a water mill can be used only where some source of flowing water is available.

2. A heat engine can be used at any time of the day whereas the wind mills can work only when wind is blowing.

3. A heat engine can be used to run vehicles like locomotives, cars and scooters but wind-mills and water-mills cannot be used to provide energy to such moving machines.

4. A heat engine is much more powerful than a wind –mill or a water mill.