Current lifestyle makes energy to be essential beyond satisfying our basic needs. Nowadays, is not possible to talk about energy without dealing with its effect on the climate. The European Union (EU) consider that energy must be secure, competitive and sustainable and the energy union and climate is a European Commission’s priority. The EU’s Energy Union framework strategy was adopted back on February of 2015 and since then, the State of the Energy Union shows by its reports the progress made and the new targets and initiatives for the closest years. The Energy Union’s strategy is hold up by five key pillars mutually reinforcing which are: energy security, market integration, energy efficiency, decarbonisation of the economy and innovation. The EU’s Energy Union supports numerous cutting edge innovation projects where hydrogen is used. The main proposes related with hydrogen are for nuclear energy applications, energy storage and fuel cells. Hydrogen, which is the most abundant element in the universe, can be converted to electricity through electrochemical processes in a fuel cell in a single step and without any moving part. In addition, in a fuel cell the by-products are waste heat and water. For these reasons, fuel cells technology (specially PEMFCs technology) have the potential to be a element to take into account in energy production satisfying the global warming targets. However, PEMFCs need more research and development and an H2 large scale infrastructure. Nowadays, only the 4% of the hydrogen consumed is produced by electrolysis, the 96% left came from fossil fuels. The present bachelor thesis focuses in one of the main current challenges in fuel cell industry: water management. A correct water management is a key factor for high PEMFC performance and durability. In order to achieve a global vision of water management and also to set a zone of stable operation in the UC3M PEMFC laboratory for upcoming works this bachelor thesis is divided in 5 main chapters. The first chapter focuses in fuel cell technology from its origin to its nowadays main applications. The second chapter deals with the PEMFC and its state of art. In the third chapter a simplified modelling of balance of mass and water is performed for a theoretical analysis of the experimental conditions. The fourth chapter summarizes all the experiments performed in the UC3M PEMFC laboratory and gives as a result a zone of stable operation that will be useful for further projects. Finally, a global conclusion of the results obtained over the bachelor thesis is presented. This present bachelor thesis involves the starting point for future hydrogen PEMFC investigation in the UC3M.Ingeniería de la Energí
