Time Span of the renewability of fuels is a major factor when considering what type of fuel to use in a project. Fossil fuels, including ___,___,and___,require ___ to___ of years to renew. Alternative fuels, including ___,___, and___ power, have a huge advantage since they require between ___ to about one ___ years to renew. Making the ___ fuels the preferred choice for the conversation of natural resources.