This book provides an outlook on recent investigated combinations of membrane operations and renewable energy sources (solar, wind, geothermal, etc.) in the field of water desalination (seawater and brackish water), wastewater treatment and hydrogen production. The combination of a renewable energy facility with a membrane process not only solves the sanitation problem of isolated regions, but also enables a more cleaner wastewater treatment system in view of carbon emission and resource recovery. Regarding biomass, the integration of membrane reactors in the production processes of green fuels in the logic of the process intensification strategy is also considered.