Distributed production of green hydrogen

Hydrogen is addressed as the best storage media for renewable energy and as an alternative to the batteries. The main issue claimed for this solution is that green hydrogen has a high production cost. In fact, it currently costs between two and three times more than hydrogen produced from fossil fuels (e.g., methane steam reforming). Nowadays, all over the world a lot of efforts are dedicated to reduce the production cost of green hydrogen. Quite all of the running project are addressed to large scale centralised production and/or to the reduction of the electrolysers cost by acting on materials, components and stacks development. Moreover, in evaluating the green hydrogen production cost usually just hydrogen is considered disregarding the by-products of the hydrogen cycle from production to application. Also additional hydrogen advantages are usually disregarded. In the present work the authors propose a different approach. Looking at the today available technologies and at the today market cost, distributed small scale green hydrogen production is proposed for the design of integrated energy systems according to poly-generation concept. This concept is supported by case study simulation results developed in recent years. In particular valorisation of green oxygen, for small and medium enterprises and hospitals, and waste heat recovery for residential applications, was considered. The results indicate that oxygen valorisation could be really effective, while waste heat valorisation is not economically viable today but have potentialities for the future. In this paper we present a resume of our previous results, already published, and new results today under publication, proposing an hydrogen based poly-generation system adaptable for different kind of applications.