SDG&E is developing a Power-to-Gas-to-Power (P2G2P) project which will use hydrogen as the energy storage medium.
The energy storage system will:
− Use a grid-connected electrolyzer to generate hydrogen
− The hydrogen will be stored in high-pressure tanks
− A fuel cell will consume the stored hydrogen to produce grid power
− All created hydrogen is used exclusively by the fuel cell. The system will start as long-duration (8+ hours) energy storage.
The system duration may be expanded to greater hours through the addition of more hydrogen tanks, or to support even longer durations (e.g., multi-day weather events)