Explain why ecosystem require a continuous input of energy from the Sun

The sun supplies the most energy in the food web. Energy is passed on in the web when one organism eats another. Producers get their energy from sunlight and are the source for most energy in an ecosystem. Energy in an ecosystem is passed on from the producers, to herbivores who eat the producers, and to carnivores who eat the herbivores, and on. In this energy chain, the majority of the energy is either used up or lost - it isn’t stored. If the sun was not providing a continuous energy input, then the energy would quickly run out.