Biofuel sources are renewable energy sources that can be used to replace fossil fuels. ALGAE, CORN, PEAT, and peanut oil are all examples of biofuel sources. ALGAE is a type of aquatic plant that can be used to produce biodiesel. CORN is a grain crop that can be used to produce ethanol. PEAT is a type of soil material that can be used to produce methane. Peanut oil is a vegetable oil that can be used to produce biodiesel.