Scientists are busy making equipment based on solar energy because solar energy is taken as the most important and effective alternative source of energy as it is available in every part of the earth and doesn't have any negative effects on the environment. The light energy from the sun is converted into electrical energy with the help of photoelectric cells. The converted electric energy can be used again to get heat, light, etc. without having any deterioration to the environment.
So, it is the best alternative source of energy pus the energy crisis further.