In this chapter, the eco-friendly applications, disposal, and the risks of inorganic nanoparticles to human health and to the environment are discussed, including the advancements in the green applications of green nanomaterials for their sustainable and competitive energy systems. The first section summarizes an introduction with the importance of the nanomaterials in scientific and industrial applications. The second and third sections present green nanoparticles applications for energy generation (green electricity generation by wind and solar energies, luminescent solar concentrators, and photovoltaics and bioenergy production). In the fourth section, the effects of nanotechnology on the human health and ecosystems and also regulations to work with nanomaterials are presented. This chapter illustrates the main principles and progress of nanotechnology and their positive and negative impacts into the environment and human health.