Power Quality in Power Systems and Electrical Machines, 2nd Edition

11.3.18 Hydrogen Generation and Storage

A well-known way of splitting water (H₂O) is by electrolysis [151]. A container (trough) contains distilled water and two electrodes -- the anode (A) and cathode (C) consisting of either platinum or nickel -- connected to a DC current source. Pure H₂O is a poor conductor; the addition of H₂SO₄ to the water makes the solution conducting. Although the solution of H₂O and H₂SO₄ heats up - due to the losses caused by the current flowing from anode to cathode- at the anode oxygen O₂ and at the cathode hydrogen H₂ is accumulated. The efficiency of splitting H₂O based on electrolysis is about η_electrolysis = 80%, that is, 20% of the energy is converted to heat within the electrolysis process. The energy density ...