The producers lie at the base of all food webs or food chains. Thus, it has 100% of energy. Now a consumer lying at trophic level I will get its food from producer. The food shall provide nearly 10% of the total energy of producers to the consumers at trophic level 1. Likewise all the subsequent trophic levels will receive nearly 10% of the energy contained within the organism lying at precedent trophic level.
Hence, in this way a food chain or food web also describes the movement of energy from one organism to other.
