Final answer:
The main alternatives to fossil fuels include solar, wind, hybrid vehicles, ethanol, biodiesel, natural gas, and hydrogen fuel cells for transportation.
Step-by-step explanation:
The main alternatives to fossil fuels include renewable energy sources such as solar and wind, as well as hybrid vehicles, ethanol, biodiesel, natural gas, and hydrogen fuel cells for transportation.
Solar energy involves capturing the sun's rays and converting them into electricity using photovoltaic cells. Wind energy harnesses the power of wind to generate electricity through wind turbines. Hybrid vehicles use a combination of an internal combustion engine and an electric motor to reduce fuel consumption and emissions.
Ethanol and biodiesel are biofuels made from renewable sources such as corn, sugarcane, and soybeans. Natural gas is a cleaner-burning alternative to gasoline and diesel, while hydrogen fuel cells produce electricity by combining hydrogen and oxygen, emitting only water vapor as a byproduct.