Hydrogen in stationary applications: Coupling the electricity, gas and mobility sectors (Digi-HyPro)

Abstract

Global warming and continuous fossil fuel depletion are worldwide phenomena that pose challenges such as the reduction of greenhouse gas emissions and the further exploitation of renewable energy sources. Nevertheless, the transition from fossil fuels to a renewable-energy-based economy demands more innovative solutions and developments such as the Power-to-Gas-to-Power (PtoGtoP) idea. Hydrogen is considered one of the clean energy carriers in the concept of PtoGtoP. However, this strategy still suffers from several challenges, like intermittent inflows of energy, high costs, and rather low energy efficiency due to the losses during conversion and storage. The goal of the Digi-HyPro (Digitalized Hydrogen Process Chain for the Energy Transition) project is to develop an efficient and modular PtoGtoP system. The concept of this modular system, called Smart-Energy-Transform-Unit (SET-Unit), aims to design a decentralized and scalable system for clean energy demands spreading across different locations. The SET-Unit serves to optimize the connections between renewable sources and the current power and gas grid demand. Applying this concept, hydrogen generated by an electrolyzer can be stored compactly and safely in a metal hydride storage system or fed into the natural gas grid. On-demand, hydrogen can also be taken from the intermediate storage facility or the gas grid by applying gas separation techniques and can be delivered (i) to an integrated fuel cell to produce power or (ii) to a metal hydride compressor to provide hydrogen for the mobility sector (trucks, cars, trains, etc.). Component and system level simulations are performed to design, develop and optimize the individual and overall integrated system. These digital models draw critical data from experiments and are validated using prototype setups. For this purpose, experimental setups on a laboratory scale of 10 kWel, and an intermediate scale of 50 kWel are part of the Digi-HyPro project’s plan. This multidisciplinary investigation involves the optimization of the digital SET-Unit system with experimental demonstrations in kWel ranges. Final scalability studies in the industrially relevant MWel range can pave the way to an efficiently networked green energy system.