Ionic conducting membranes or solid electrolytes have the ability to selectively transport ions (e.g. O2-, OH-, H+, Na+) over a wide temperature range. The main application of these materials concerns the fields of fuel cell and electrochemical sensors. In this presentation I will focus on their implementation in electrochemical devices for energy storage. The activities of my group are focused on two different classes of ionic conducting membranes: polymers operational at temperatures below 200oC and ceramics operational at temperatures above 400oC. These materials are the core of devices used for converting sunlight and/or renewable electricity to chemical fuels. These devices can be easily scaled up due to the compact reactor design and allow novel operation modes. Light or plasma assisted catalytic and electrochemical processes take place on these reactors using H2O, CO2 and N2 as the feedstock.