The April issue of FotoVolt is online. The article “Solar generation, hydrogen, fuel cell and batteries”, on page 18, describes an evaluation of the performance of system and its operation to normalize the photovoltaic solar generation curve of a project comprising a photovoltaic solar plant and an energy storage system composed of a water electrolyzer, H2 tank, fuel cell and batteries bank, which was designed at Cesp's Porto Primavera hydroelectric plant. See on page 30 the article “Energy quality monitoring in a PV system”, where, through measurement campaigns carried out at connection point at 138 kV, the energy quality in a photovoltaic generation complex is evaluated, checking the performance of electrical system before and after your connection to the grid. Furthermore, on page 64, in “Research & Innovation” section, the article “Studies on ‘massless’ energy storage advances”, about researchers from Chalmers University of Technology who, in partnership with the KTH Royal Institute of Technology, produced a structural battery with a multifunctional performance ten times than previous structural battery prototypes. The discovery paves the way for energy storage called ‘massless’, in which the weight of the battery ‘disappears’ when it becomes part of the load-bearing structure. This issue brings also the update “Batteries for PV energy storage” buyers’ guide and “PV engineering and technical services companies: design, installation, consulting etc.” directory.