How to Power the Energy–Water Nexus: Coupling Desalination and Hydrogen Energy Storage in Mini-Grids with Reversible Solid Oxide Cells

Abstract

Sustainable Development Goals establish the main challenges humankind is called to tackle to assure equal comfort of living worldwide. Among these, the access to affordable renewable energy and clean water are overriding, especially in the context of developing economies. Reversible Solid Oxide Cells (rSOC) are a pivotal technology for their sector-coupling potential. This paper aims at studying the implementation of such a technology in new concept PV-hybrid energy storage mini-grids with close access to seawater. In such assets, rSOCs have a double useful effect: charge/discharge of the bulk energy storage combined with seawater desalination. Based on the outcomes of an experimental proof-of-concept on a single cell operated with salty water, the operation of the novel mini-grid is simulated throughout a solar year. Simulation results identify the fittest mini-grid configuration in order to achieve energy and environmental optimization, hence scoring a renewable penetration of more than 95%, marginal CO2 emissions (13 g/kWh), and almost complete coverage of load demand. Sector-coupling co-production rate (desalinated water versus electricity issued from the rSOC) is 0.29 L/kWh.

Hydrogen production from low-quality water: challenges and perspectives

“…In a similar process, a small amount of salt may carried with steam into the electrolyser and cause performance degradation/material damage. Few literature papers report on commercial SOE run on artificial seawater (demi water + 35 ppt NaCl), mainly showing short-time proof-of-concept with commercial cells, observing no damage ascribed to salt onto the tested cell operated at 800°C [19], [20]. It is claimed that sea salts are highly volatile at the cell operative temperature.…”