Carbohydrates are the body's primary and immediate source of energy.
The term clean source of energy refers to only primary energy sources as wind or solar energy. Electricity, by definition, is not a primary energy source. It is a secondary energy source that is could be produced by a clean energy source as wind or any renewable primary energy source or produced by fossil energy source as oil, natural gas, or coal.
Carbohydrates are the primary energy source for herbivores (cows, horses, etc.). Proteins are the primary energy source for carnivores (dogs, cats, etc.).
Carbohydrates are the body's primary and immediate source of energy.
The primary is the sun
The sun is the initial (primary) energy source for life. Ingestion and digestion of a food source is an animal's primary source of energy.
the sun
the sun
Wood is the first discovered primary energy source. Some believe that Solar energy (as heat caused by sun light) is the first discovered primary energy source.
the primary source of energy is sun.
Sunlight is Earth's primary source of energy.
Geothermal energy is considered a primary energy source because it comes directly from the Earth's heat stored in rocks and fluids beneath the Earth's surface. It is renewable and sustainable.