Question

we depend on light energy for fuel and food

Answer 1

Plants use the light energy from the sun to make their food. The food made by plant furthur eaten up by animals.The plants and animals living million different years ago used sunlight and which when died ended up as fossil fuels (which are of great use today!). ... Solar energy can be used to generate electricity

Answer 2

sun is ultimate source of all the form energy that exist on Earth.
Fuel we use that is coal and petroleum.these all are Fossil fuels .In these fuel contains chemical energy. These energy are fixed in these by convesion light energy and engy transfer infood chain.
Similarly in our food chemical energy present are obtained from sun during photosynthesis