Model-Based Analysis of a Combined Heat and Power System Featuring a Hydrogen-Fired Gas Turbine With On-Site Hydrogen Production and Storage
Climate science shows that the limitation of global warming requires a rapid transition towards net-zero emissions of green house gases (GHG) on a global scale.
An analysis of today’s German GHG emission data reveals the energy sector’s vital role in this transition process. Today, the energy sector is the main emitter of GHG. Thus, its decarbonization will result in a significant reduction of the overall GHG emissions. Furthermore, a GHG-neutral energy sector constitutes a prerequisite for the successful decarbonization of all other GHG emitting sectors by means of sector coupling.
GHG neutrality in the energy sector and the successful implementation of sector coupling pathways can only be achieved if sufficient renewable power is available. However, the volatility of wind- and solar-based power generation challenges the stability of power grids. The solution for these challenges is the utilization of so-called flexibility technologies.
Due to their ability to provide flexible and dispatchable power generation, gas turbines are seen as an important flexibility technology. Taking into account the overall goal of GHG neutrality, it is imperative that gas turbines fulfilling this task are operated with CO2-neutral fuels.
Furthermore, the high-temperature heat provided by gas turbines can be utilized in a wide range of combined heat and power (CHP) applications. Thus, these CHP applications constitute an important sector coupling pathway in the future.
Considering the state of the art, hydrogen is the most promising CO2-neutral gas turbine fuel and water electrolysis is the only technology enabling the large-scale production of this fuel on the basis of renewable power.
However, the continuous supply of large quantities of CO2-neutral hydrogen for the operation of hydrogen-fired gas turbines is challenging. These challenges arise due to various interdependencies between the availability of renewable power, electrolysis capacities and hydrogen storage capacities.
The present study aims to quantify these interdependencies by conducting a model-based analysis of an exemplary system configuration.
The main component of the investigated system configuration is a hydrogen-fired gas turbine that is utilized in a CHP system providing power and high-temperature heat for a generic consumer. It is assumed that the gas turbine is also capable of using natural gas as back-up fuel during time periods of insufficient hydrogen supply.
Furthermore, it is assumed that an on-site electrolyzer provides the required quantities of hydrogen for the gas turbine operation. The electrolyzer is connected to a hydrogen storage system that enables an intermediate storage of hydrogen.
Regarding the supply of renewable power, it is assumed that a local wind farm provides power for both the generic consumer and the operation of the electrolyzer.
In a first step, detailed steady-state models of all system components are developed and parametrized based on publicly available data. In a following step, the operation of the overall system configuration is simulated repeatedly for a one-year period with varying key design parameters. The simulation results are subsequently analyzed using selected technical evaluation criteria. Based on this analysis, distinct correlations between the key design parameters and the evaluation criteria are derived.
The second aim of the present study is the assessment of the economic viability of the investigated system configuration.
In order to account for the economic potential resulting from the time dependent revenue for the feed-in of excess wind power into the grid, a day-ahead operational optimization algorithm is integrated into the simulation model.
Utilizing the operational optimization algorithm, the one-year operation of the system configurations is simulated repeatedly considering predefined sets of design parameters. Subsequently, the economic viability of these sets of design parameters is analyzed with the help of key economic parameters.
Model-Based Analysis of a Combined Heat and Power System Featuring a Hydrogen-Fired Gas Turbine With On-Site Hydrogen Production and Storage
Category
Technical Paper Publication
Description
Session: 44-04 Large-scale Thermal storage and Power-to-gas Energy Storage
ASME Paper Number: GT2020-16071
Start Time: September 21, 2020, 09:45 AM
Presenting Author: Thomas Bexten
Authors: Thomas Bexten RWTH Aachen University - Institute of Power Plant Technology, Steam and Gas Turbines
Manfred Wirsum RWTH Aachen University - Institute of Power Plant Technology, Steam and Gas Turbines
Björn Roscher RWTH Aachen University - Chair for Wind Power Drives
Ralf Schelenz RWTH Aachen University - Chair for Wind Power Drives
Georg JacobsRWTH Aachen University - Chair for Wind Power Drives