Monologue: Energy sources: solar power, wind power and nuclear power. Renewable and non-renewable energy sources.

Good afternoon. I've been asked to talk about three different energy sources.

To start with, it is important to define what is understood by energy source. It is anything of which we can obtain energy. For example, a hydroelectric station uses a stream of water to generate energy which later we will use electric power to run a computer, a TV, refrigerator, etc.

It is a very well-known fact that our advanced societies are based on consumption of very large amounts of energy, that's why energy sources are really important.

However each energy source has its pros and cons:

- Solar power: It uses the energy of sun to generate electricity. It is cheap and non-polluting but the power it provides is small and it can't be used in cloudy days.

- Wind power. In that case uses the wind flow to produce electricity. As solar power it is cheap and non-polluting but the power delivered is big. However the production of electrical energy depends on the wind blow.

- Nuclear energy in contrast provides great quantities of energy constantly, without depending on the flow of the wind or if the the sun is shining. It is also cheap if we don't take into account the cost of their pollution generated by its waste. On the contrary it is a really dangerous technology, and accident can cause great heath problems to the population and the reserves of nuclear fuel are running out.

As to the second part of the question, we can qualify an energy as renewable when it will be always available to use it. From this point of view solar energy and wind energy are considered as renewable energies. Moreover, nuclear energy is a non renewable energy, depending on the rate of our consumption it is for sure that some day in the future we have run out all nuclear fuel available.

Other than that, renewable energies are more respectful with environment. That's why many scientist consider that the future world will be renewable, or simply our current society won't exist in the future world.

In conclusion, if society wants to have a future, it should start using renewable energies as solar power or wind power.