A producer is an organism that captures energy and stores it in food as chemical energy. The producers of an ecosystem make energy available to all the other living parts of an ecosystem.

They capture 1% of energy from sunlight and use it to produce food. Then when consumers feed on plants the 10% rule of energy transfer is followed. In that, at each trophic level, about 10% of the energy of previous trophic level is passed to the next trophic level of food chain.

The diagram is shown below:

This is how energy transfer varies between sun to plants and then plants to various consumer levels.