Advances in power-to-gas technologies: cost and conversion efficiency†
Widespread adoption of hydrogen as an energy carrier is commonly believed to require continued advances in power-to-gas (PtG) technologies. Here we provide a comprehensive assessment of the dynamics of system prices and conversion efficiency for three currently prevalent PtG technologies: alkaline, polymer electrolyte membrane, and solid oxide cell electrolysis. We analyze global data points for system prices, energy consumption, and the cumulative installed capacity for each technology. Our regression results establish that over the past two decades every doubling of cumulative installed capacity resulted in system prices coming down by 14–17%, while the energy required for electrolysis was reduced by 2%. On the basis of multiple forecasts of future deployment growth, as well as policy and industry targets, our calculations project that all three technologies will become substantially cheaper and more energy-efficient in the coming decade. Specifically, the life-cycle cost of electrolytic hydrogen production is projected to fall in the range of $1.6–1.9 per kg by 2030, thereby approaching but not reaching the $1.0 per kg cost target set by the U.S. Department of Energy.