A photovoltaic system for generating an output voltage that is uninfluenced by varying irradiation, includes a photovoltaic source having an input terminal and an output terminal. In one preferred embodiment, each transaction is associated with a token. The invention also provides methods for making neo-tryptophan, neo-tryptophan derivatives, serotonin-like neo-tryptophan derivatives, and compositions containing these compounds. The end users whose submission material was included in the released content are rewarded.