How much energy do organisms on each trophic level use? What is the energy used for?

10% of energy is used by organisms on every trophic level. The energy obtained will be used in metabolic processes by the organism.

Explanation

The energy transfer at each level is very low ie only 10%.

Out of the total energy consumed by organism, much energy gets dissipated as heat during metabolic processes, reproduction, growth and repair in an organism.

As the trophic level goes up in a food pyramid the biomass and number of organisms reaching the trophic level decreases.

Also, not many organisms get eaten by consumers and many molecules in the organism eaten are not digestible by consumers and released as waste contributes to the loss of energy. We can now deduce that instead of contributing to biomass the waste gets decomposed by microorganisms and cycle continues.