Columbia University explains that energy from the sun travels to other planets through electromagnetic waves in a process called radiation. This way, energy can be transferred through empty space without relying on matter.
Solar energy, in the form of heat and light, travels from the sun to Earth through the process of radiation. This radiation is largely visible as light to the naked eye, although it also includes ultraviolet and infrared radiation as well. Once the electromagnetic waves from the sun reach the Earth, it is absorbed and transfers heat to those bodies, be they solid, liquid or gaseous, that it encounters. Both the atmosphere and the ocean on the Earth allows this radiation to warm up the entire planet and not just select parts. Without these components, the Earth would be too hot to inhabit where the radiation is absorbed by the Earth and too cold to inhabit in those areas not directly in the path of the radiation.
The solar radiation starts out at 63 million watts per square meter, but the long journey to the Earth reduces this to 1,360 watts per square meter. The amount of radiation that reaches any given point on Earth is then subject to many variables, such as the elliptical orbit of the Earth, its spherical shape and its tilt.