State the forms in which energy stored in the oceans manifests itself. Which one of these is utilized in OTEC systems?

7 Why can wind energy farms be established only at specific locations? Give reasons to support your answer. 8 It is difficult to use hydrogen as a source of energy, although its calorific value is quite high. Explain. 10 With the help of a diagram, explain the process of destructive distillation of wood. 11 Why is charcoal considered a better fuel than wood? What are the disadvantages of converting wood into charcoal?