... DisadvantagesGeother-mal heat - Clean and safe , inexpensive - Available only in a few placesWind - Abundant and unlimited, clean and safe - Not available when there is no windSolar energy - Plentiful ... renewable•convenient•cheap, simple devices/technology•dangerous•expensive•polluted•limited, non-renewable•harmful•exhausted UNIT 11 Task 1. The following statements list some advantages and disadvantages of ... renewable - Influenced by the presence of clouds or pollution , can’t be produced during nighttime WaterClean and safe , renewable - Must build dams , so expensiveNuclear energy - Unlimited...