15. Once the dam is built, the energy is free. No waste or pollution produced. Much more reliable than wind, solar or wave power. Water can be stored above the dam ready to cope with peaks in demand. Electricity can be generated constantly. Advantages
28. We even use solar power in orbit! Why would that be a good way to power satellites? Video clip on solar power
29.
30. Doesn't work at night. Very expensive to build solar power stations. Solar cells cost a lot to make. Can be unreliable unless you're in a very sunny climate. Disadvantages