The correct answer is option 1, Nuclear energy. Nuclear energy is a conventional energy source, not a non-conventional one.

Let`s dissect each option to understand why option 1 is the correct answer.

Option 1: Nuclear energy - Nuclear energy is obtained by harnessing the energy released from nuclear reactions. Although it is a cleaner form of energy compared to fossil fuels, it is still considered a conventional energy source due to its well-established and widely used technology.

Option 2: Solar energy - Solar energy is a non-conventional energy source. It is obtained from the sun`s rays and can be converted into electricity using solar panels or used directly for heating and lighting.

Option 3: Wind energy - Wind energy is also a non-conventional energy source. It is obtained by using wind turbines to convert the kinetic energy in the wind into electricity.

Option 4: Tidal power - Tidal power is another example of non-conventional energy. It harnesses the energy from the gravitational pull of the moon and the sun on the Earth`s tides to generate electricity.

In conclusion, option 1 (Nuclear energy) is not a non-conventional energy source.