Netherlands
Can an Energy Only Market Enable Resource Adequacy in a Decarbonized Power System? A Co-simulation with Two Agent-based-models
Feb 2024
Publication
Future power systems in which generation will come almost entirely from variable Renewable Energy Sources (vRES) will be characterized by weather-driven supply and flexible demand. In a simulation of the future Dutch power system we analyze whether there are sufficient incentives for market-driven investors to provide a sufficient level of security of supply considering the profit-seeking and myopic behavior of investors. We cosimulate two agent-based models (ABM) one for generation expansion and one for the operational time scale. The results suggest that in a system with a high share of vRES and flexibility prices will be set predominantly by the demand’s willingness to pay particularly by the opportunity cost of flexible hydrogen electrolyzers. The demand for electric heating could double the price of electricity in winter compared to summer and in years with low vRES could cause shortages. Simulations with stochastic weather profiles increase the year-to-year variability of cost recovery by more than threefold and the year-to-year price variability by more than tenfold compared to a scenario with no weather uncertainty. Dispatchable technologies have the most volatile annual returns due to high scarcity rents during years of low vRES production and diminished returns during years with high vRES production. We conclude that in a highly renewable EOM investors would not have sufficient incentives to ensure the reliability of the system. If they invested in such a way to ensure that demand could be met in a year with the lowest vRES yield they would not recover their fixed costs in the majority of years.
Towards Low-carbon Power Networks: Optimal Location and Sizing of Renewable Energy Sources and Hydrogen Storage
Apr 2024
Publication
This paper proposes a systematic optimization framework to jointly determine the optimal location and sizing decisions of renewables and hydrogen storage in a power network to achieve the transition to low-carbon networks efficiently. We obtain these strategic decisions based on the multi-period alternating current optimal power flow (AC MOPF) problem that jointly analyzes power network renewable and hydrogen storage interactions at the operational level by considering the uncertainty of renewable output seasonality of electricity demand and electricity prices. We develop a tailored solution approach based on second-order cone programming within a Benders decomposition framework to provide globally optimal solutions. In a test case we show that the joint integration of renewable sources and hydrogen storage and consideration of the AC MOPF model significantly reduces the operational cost of the power network. In turn our findings can provide quantitative insights to decision-makers on how to integrate renewable sources and hydrogen storage under different settings of the hydrogen selling price renewable curtailment cost emission tax price and conversion efficiency.
Profitability of Hydrogen Production: Assessment of Investments in Electrolyser Under Various Market Circumstances
Aug 2024
Publication
Although hydrogen is increasingly seen as a crucial energy carrier in future zero-carbon energy system a profitable exploitation of electrolysers requires still high amounts of subsidies. To analyze the profitability of electrolysers attention has to be paid not only to the costs but also to the interaction between electricity and hydrogen markets. Using a model of internationally integrated electricity and hydrogen markets this paper analyses the profitability of electrolysers plants in various future market circumstances. We find that in particular the future supply of renewable electricity the demand for electricity as well as the prices of natural gas and carbon strongly affect the profitability of electrolysis. In order to make massive investments in electrolysers profitable with significantly lower subsidy requirements the amount of renewable electricity generation needs to grow strongly and the carbon prices should be higher while the demand for electricity should not increase accordingly. This research underscores the critical role of market conditions in shaping the viability of hydrogen electrolysis providing valuable insights for policymakers and stakeholders in the transition to a zero-carbon energy system.
Will Hydrogen and Synthetic Fuels Energize our Future? Their Role in Europe's Climate-neutral Energy System and Power System Dynamics
Aug 2024
Publication
This study evaluates the technoeconomic impacts of direct and indirect electrification on the EU's net-zero emissions target by 2050. By linking the JRC-EU-TIMES long-term energy system model with PLEXOS hourly resolution power system model this research offers a detailed analysis of the interactions between electricity hydrogen and synthetic fuel demand production technologies and their effects on the power sector. It highlights the importance of high temporal resolution power system analysis to capture the synergistic effects of these components often overlooked in isolated studies. Results indicate that direct electrification increases significantly and unimpacted by biomass CCS and nuclear energy assumptions. However indirect electrification in the form of hydrogen varies significantly between 1400 and 2200 TWhH2 by 2050. Synthetic fuels are essential for sector coupling making up 6–12% of total energy consumption by 2050 with the power sector supplying most hydrogen and CO2 for their production. Varying levels of indirect electrification impact electrolysers renewable energy and firm capacities. Higher indirect electrification increases electrolyser capacity factors by 8% leading to more renewable energy curtailment but improves system reliability by reducing 11 TWh unserved energy and increasing flexibility options. These insights inform EU energy policies stressing the need for a balanced approach to electrification biomass use and CCS to achieve a sustainable and reliable net-zero energy system by 2050. We also explore limitations and sensitivities.
A Thermodynamically Consistent Methodology to Develop Predictive Simplified Kinetics for Detonation Simulations
Sep 2023
Publication
The number of species and elementary reactions needed for describing the oxidation of fuels increases with the size of the molecule and in turn the complexity of detailed mechanisms. Although the kinetics for conventional fuels (H2 CH4 C3H8...) are somewhat well-established chemical integration in detonation applications remains a major challenge. Significant efforts have been made to develop reduction techniques that aim to keep the predictive capabilities of detailed mechanisms intact while minimizing the number of species and reactions required. However as their starting point of development is based on homogeneous reactors or ZND profiles reduced mechanisms comprising a few species and reactions are not predictive. The methodology presented here relies on defining virtual chemical species such that the thermodynamic equilibrium of the ZND structure is properly recovered thereby circumventing the need to account for minor intermediate species. A classical asymptotic expression relating the ignition delay time with the reaction rate constant is then used to fit the Arrhenius coefficients targeting computations carried out with detailed kinetics. The methodology was extended to develop a three-step mechanism in which the Arrhenius coefficients were optimized to accurately reproduce the one-dimensional laminar ZND structure and the D−κ curves for slightly-curved quasi-steady detonation waves. Two-dimensional simulations performed with the three-step mechanism successfully reproduce the spectrum of length scales present in soot foils computed with detailed kinetics (i.e. cell regularity and size). Results attest for the robustness of the proposed methodology/approximation and its flexibility to be adapted to different configurations.
Voltage Losses in Zero-gap Alkaline Water Electrolysis
Apr 2021
Publication
Reducing the gap between the electrodes and diaphragm to zero is an often adopted strategy to reduce the ohmic drop in alkaline water electrolyzers for hydrogen production. We provide a thorough account of the current–voltage relationship in such a zero-gap configuration over a wide range of electrolyte concentrations and current densities. Included are voltage components that are not often experimentally quantified like those due to bubbles hydroxide depletion and dissolved hydrogen and oxygen. As is commonly found for zero-gap configurations the ohmic resistance was substantially larger than that of the separator. We find that this is because the relatively flat electrode area facing the diaphragm was not active likely due to separator pore blockage by gas the electrode itself and or solid deposits. Over an e-folding time-scale of ten seconds an additional ohmic drop was found to arise likely due to gas bubbles in the electrode holes. For electrolyte concentrations below 0.5 M an overpotential was observed associated with local depletion of hydroxide at the anode. Finally a high supersaturation of hydrogen and oxygen was found to significantly increase the equilibrium potential at elevated current densities. Most of these voltage losses are shown to be easily avoidable by introducing a small 0.2 mm gap greatly improving the performance compared to zero-gap.
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