What is ocean thermal energy?

What are the environmental consequences of using fossil fuels? Suggest the steps to minimize the pollution caused by various sources of energy,including non-conventional sources of energy.

Aditya suggests his family to install a solar water heater at their residence. But some of the family members were in favour of installing an electric geyser.
$(a)$ Who,according to you,is taking a correct decision? Mention the value exhibited by Aditya.
$(b)$ Also,give reasons (at least $2$) for your answer.

Name a non-conventional renewable source of energy which can be harnessed for $24$ hours throughout the year.

What is a wind energy farm? Mention the steps involved in generating electricity from such farms.

How is the slurry left over after the generation of biogas in a biogas plant used?