59073 - Techno-Economic Analysis of a Hydrogen Production and Storage System for the On-Site Fuel Supply of Hydrogen-Fired Gas Turbines 

Hydrogen-fired gas turbines have the potential to play an important role in future carbon-neutral energy and industry sectors. A prerequisite for the successful implementation of hydrogen-fired gas turbines is the availability of sufficient quantities of hydrogen produced in a CO2-neutral way. Based on the state of the art, the combination of electrolysis and renewable power generation is considered the most relevant pathway for a large-scale production of CO2-neutral hydrogen. However, with regard to the fuel supply of hydrogen-fired gas turbines, this pathway is associated with various technical and economic challenges. This applies in particular to fuel supply configurations in which electrolyzers are installed directly at gas turbine sites and on-site hydrogen storage is required as a result. Challenges derive from the interdependencies between the inherent volatility of renewable power generation, available electrolysis capacity, available hydrogen storage capacity and the respective operational demands to be met by the gas turbine.

A previous study by the authors (GT2020-16071) investigated these interdependencies from a technical point of view by conducting a detailed model-based analysis of an exemplary system configuration. Within the analyzed system configuration, a hydrogen-fired gas turbine is tasked with the provision of CO2-neutral power and heat for an industrial consumer. The hydrogen is produced by an on-site electrolyzer and temporarily stored in pressure vessels. The renewable power required for the operation of the electrolyzer is either generated by a set of on-site wind turbines or provided by the power grid. During periods of insufficient hydrogen supply, natural gas is used as backup fuel to maintain gas turbine operation. As a result, these periods are associated with the emission of CO2.

Considering the same exemplary system configuration and utilizing the existing simulation environment, the present study aims to extend the prior investigation by focusing on the economic viability of the use of CO2-neutral hydrogen as gas turbine fuel and the corresponding on-site supply of hydrogen. For this purpose, the net present value (NPV), the levelized cost of electricity (LCOE) and the levelized cost of hydrogen (LCOH) are selected as main economic indicators. Required input data for the calculation of these indicators (e.g. cost of CO2 emission allowances) are derived from the regulatory and economic framework of the German energy sector. Using the selected indicators, the impact of various design parameters (e.g. number of on-site wind turbines, available electrolysis capacity and available hydrogen storage capacity) on the economic viability of the investigated system configuration is analyzed. Furthermore, the impact of different operational strategies regarding the interaction with the power grid (i.e. consumption of additional power provided by the grid and feed-in of local power surpluses into the grid) is investigated as well.

To complete the techno-economic investigation, the results of the economic assessment are correlated with the corresponding results of the prior technical analysis (e.g. achievable level of CO2 emission reduction, utilization rate of system components). In a final step, the impact of the considered regulatory and economic framework conditions on the obtained techno-economic analysis results is discussed.