The main topics covered in this book will be introduced. An overview of the historical trend of energy consumption over the last one hundred years will show the crucial need for renewable sources progressively replacing fossil and nuclear power supply. Among renewables, solar harvesting is surely the most promising technology, already playing a significant role in the global power landscape. Demand for higher efficiencies and lower power costs may open yet partially unexplored paths where PV modules are paired to ancillary harvesters to improve the usability of solar power, which will be the main focus of this book.