Read the following case and answer the following questions:
A village is located near a large dam where a hydroelectric power station has been built. Water stored behind the dam is released through large pipes, causing it to flow at high speed. The moving water rotates huge turbines connected to generators, which produce electricity. This electricity is supplied to the homes, schools, hospitals, and farms in the village. Since the power station uses flowing water instead of burning fossil fuels, it produces electricity with very little air pollution. However, hydroelectric power stations can only be built in places where a large and continuous supply of water is available.
1. Hydroelectric power is classified as a renewable source of energy because
2. Why is hydroelectric power considered environmentally friendly?
3. Which of the following is a limitation of hydroelectric power stations?
4. The villagers want to add another renewable source of electricity to reduce their dependence on the dam during dry seasons. Which source would be the best choice?