71 we are looking for a cheap, clean and effective source of energy, which does not cause pollution or waste natural resources

72 All present most of our electricity comes from the use of coal, gas, oil and nuclear power

73. This power could provide sun.

74 one percent of solar energy reaching the Earth can provide enough power for the total population

75 Many countries have already been using solar energy

76 Solar panels are placed on the roof of the house and sun's energy is used to heat water

77 The energy can be stored a number of days

78 On cloudy days, you can use solar energy too

79 VN has an advanced technology for solar energy

80 Cars will have used solar energy instead of gas by the year 2030