Describes the science behind unusual sources of energy that could be used in place of fossil fuels. Part of the "Nasty (But Useful!) Science" series. Interest Level: 3-6 Reading Level: 5.0 ATOS Book Level: 5 AR Interest Level: MG AR Points: .5 AR Quiz: 137679EN Reading Counts Level: 5.2 Reading Counts Points: 3 Lexile Measure: 790 Guided Reading Level: R.