How Does The Energy Flow In Food Chain Of Ecosystem?

Energy in the form of radiant heat and light from the sun flows through an ecosystem passing through the different tropic levels and radiates again back into outer space. The total amount of energy fixed by plant is gross primary productions. The amount of energy left after plants have met their respiratory needs is net primary production, which shows up as biomass.
About 1 % of the total energy from the sun is trapped by the producers in an eco system. The remaining 99% of solar energy is used to evaporate water, heat up soil and then lost to the outer space.
As energy is transferred from one tropic level to the next, from producer to primary consumer, between 80to 90% of the original energy is lost as heat as a by-product of respiration.
However a continuous flux of energy from the sun prevents ecosystem from running down. A pyramid of energy can be constructed showing energy transfer in a community of organisms.

At each level of food chain, about 90% of energy is lost in form of heat. The total energy passed from one level to the other is about  one tenth of the energy received from the previous organism.