The heat energy of the sun causes the air heating. The heated air, density becomes less and starts to go up, at the same time , cold air having high density comes down to fill the partial vacuum state which forms the wind. This wind now can be used to generate electricity. Similarly the suns energy is used up by the plant through photosynthesis and animals eat plants. So solar energy is indirectly stored inside the plant as well as animals which when buried inside the earth crust for million of years form fossil fuel or mineral fuel. Hence wind and mineral fuel are the indirect sources of solar energy.
It provides heat to the photovoltaic cells to generate electric power. You will find several indirect forms of this direct energy. For instance, wind, fossil fuel, biomass, and hydro energy are the indirect forms of solar energy.Sun is the direct or indirect source of renewable energies.
The radiation that does reach the Earth is the indirect source of nearly every type of energy used today. The exceptions are geothermal energy, and nuclear fission and fusion. Even fossil fuels owe their origins to the sun; they were once living plants and animals whose life was dependent upon the sun.