20: Earth's Energy Last updated Save as PDF Page ID5609 Contributed by CK12CK12 20.1: Energy Resources20.2: Obtaining Energy Resources20.3: Energy Conservation20.4: Renewable vs. Nonrenewable Energy Resources20.5: Earth's Energy- Challenge 120.6: Fossil Fuel Formation20.7: Coal Power20.8: Petroleum Power20.9: Natural Gas Power20.10: Fossil Fuel Reserves20.11: Nuclear Power20.12: Earth's Energy- Challenge 220.13: Solar Energy20.14: Hydroelectric Power20.15: Wind Energy20.16: Geothermal Energy20.17: Biomass Energy20.18: Earth's Energy- Challenge 3