Nowadays it is absolutely impossible to imagine the technology development without alternative sources of energy. The alternative to the carbohydrates, the amount of which runs short, are issues of current importance. Solar industry is one of the fast growing leaders in the list of non-traditional energy sources, but nobody knows, what kind of energies will be traditional in 50-100 years.
The base for solar cell is and probably will be silicon. The change of silicon is still very expensive and ineffective...