Hydrogen can play a role in electrochemical storage of RES?

Just few year ago the debate was about 20-30% of maximum contribution of Renewable Energy on electric grid. Today many EU countries reached the 20% RES contribution to electric power, and some countries reached also 30-40%. Today many countries in the world, not only in Europe, have as target to reach at the least 50% of renewable energy before 2030 or 2050, and the 100% electricity from RES is considered feasible. To reach these targets, availability of large energy storage systems is fundamental for matching production and consumption. Electrochemical storage allow to reach good efficiency and grant a fast response to grid loads. In the last few years large efforts have been dedicated to development/implementation of large batteries storage systems. Hydrogen production by electrolysis has been progressively less considered as storage system, and addressed mainly for car refuelling, because hydrogen continue to have a great appeal as future fuel for zero emission vehicles. In this scenario, hydrogen could play a role in future electrochemical storage of RES power? What could be the advantage and drawback of RES power storage by electrolysis for hydrogen production? In our studies for smart grids and smart cities, we consider the electrochemical energy storage of renewable electricity a basic part of the smart power systems. Hydrogen is a part of this storage that cannot be neglected, because it could allow to link three very important nets in Europe: the electric grid, the car refuelling network and the natural gas distribution network.