As per the law of 10% just 10% of the total energy consumed by an organism at a particular trophic level is available for the organism at next trophic level. So, whatever energy is converted into biomass by a producer; just 10% of it is available for the primary consumer. Similarly, just 10% of the energy consumed by the primary consumer is available for secondary consumer. Due to this, organisms at a higher trophic level less energy available.