Abstract
This paper investigates the contribution of hydrogen electrolysers (HEs) for frequency related Ancillary Services (AS), namely Frequency Containment Reserve (FCR), Synthetic Inertia (SI) , Fast Frequency Response (FFR) in future operation scenarios in the Iberian Peninsula (IP) considering low system iner-tia. The proposed framework for analysis consists of a dynamic model developed in MATLAB/Simulink. Simulations show that an instantaneous inverter based resource (IBR) trip induced by a grid fault may lead to the occurrence of values of Rate of Change of Frequency (RoCoF) close to undesirable thresholds if the FCR is provided solely by the conventional generators. The obtained results illustrate that HEs can outperform conventional generators on the provision of FCR. Furthermore, the FCR is unable to unlock the full potential of fast responding HEs. This suggests the advantage of providing additional AS such as SI or FFR in critical periods. Simulations also show that the benefit of additional AS can be limited in specific conditions, especially depending on the evolution of HEs' ramping capabilities, but are still a relevant complement to other solutions designed to deal with low inertia in power systems such as synchronous compensators.& COPY; 2023 Elsevier Ltd. All rights reserved.

Abstract
There is growing recognition that decarbonisation of existing uses of electricity is only 'part of the story' and that closer attention needs to be given to demand for energy in heating or cooling and in transport, and to all the energy vectors and infrastructures that supply the end-use demand. In this respect, concepts such as 'multi-energy systems' (MES) have been put forward and are gaining increasing momentum, with the aim of identifying how multiple energy systems that have been traditionally operated, planned and regulated in independent silos can be integrated to improve their collective technical, economic, and environmental performance. This paper addresses the need for modelling of MES which is capable of assessing interactions between different sectors and the energy vectors they are concerned with, so as to bring out the benefits and potential unforeseen or undesired drawbacks arising from energy systems integration. Drivers for MES modelling and the needs of different users of models are discussed, along with some of the practicalities of such modelling, including the choices to be made in respect of spatial and temporal dimensions, what these models might be used to quantify, and how they may be framed mathematically. Examples of existing MES models and tools and their capabilities, as well as of studies in which such models have been used in the authors' own research, are provided to illustrate the general concepts discussed. Finally, challenges, opportunities and recommendations are summarised for the engagement of modellers in developing a new range of analytical capabilities that are needed to deal with the complexity of MES.

Abstract
This paper evidences the ability of a VSM-based grid-forming to mitigate stability problems of different classes, raising a special concern towards the importance of its location in systems with large converter-interfaced renewable energy systems. Within this context, a multi-class stability assessment, that pillars on the simulation of different nature disturbances and in the subsequent evaluation of a 4 index set, was performed. Such analysis was carried out on a modified version of the IEEE39 Test System, using DigSILENT Power Factory as the simulation engine.

Abstract
The Transmission System Operators (TSOs) from Portugal and Spain do not procure Frequency Containment Reserve (FCR) through market mechanisms. A Virtual Power Plant (VPP) aggregating sources such as wind and solar power and hydrogen electrolysers (HEs) would benefit from participation in this ancillary service market. The methodology proposed in this paper allows to quantify the costs of the participation of the Iberian TSOs in the FCR Cooperation as well as the revenues of a VPP that aggregates wind and solar power and HEs. Results are produced using real data from past market sessions. The Portuguese TSO would have paid roughly 10 M€ to participate in this market in 2022. Using data for the same country and year, a VPP (aggregating the HEs expected to be connected by 2025) would have revenues over 2 M€. © 2023 IEEE.

Abstract
This paper describes a study that sought to analyse the impact of an active demand response on the frequency stability of the Iberian Peninsula for operation scenarios extending to 2040. For that purpose, one developed dynamic models for primary and secondary frequency control provision from demand-side resources, namely Electric Vehicles (EV), thermostatically controlled loads (TCL), and electrolysers. Those models were developed under a Matlab/Simulink environment, and added to a two-area control model representative of the Iberian Peninsula interconnected to the CESA area. Then, one ran simulations of reference disturbances (loss of a large generator or distributed generation) in the developed platform, once it was fully implemented.

Abstract
Assessing the societal contributions of research is not simple, especially for research projects that produce outputs with low technology readiness level. This paper analyses the potential societal impacts of research resulting in technologies with low maturity, but with the potential to be further developed in the long-term. It uses the case of the ESGRIDS (Enhancing Smart Grids for Sustainability) collaborative research project and its outputs aimed at enhancing smart grids for sustainability. Data was collected from the four participant research teams through two sequential questionnaires about technologies' state of development and expected long-term societal effects. Among the main results, we underscore the influence of individual perceptions and organisational contexts over the process of eliciting future developments. The analysis of technologies' status, barriers for market uptake, and potential future developments was translated into a technology roadmap, which outlined the time-dimension for technology maturity evolution and implementation impacts. The technologies developed within the ESGRIDS project can contribute to support consumers' energy decision-making and to encourage them to have a more active role in the electricity market. Those technologies can also create job opportunities associated with the development of new products and services, and contribute to mitigating climate change by promoting the use of renewable energies thus reducing carbon dioxide emissions, in addition to contributing to energy cost reduction by optimizing the use of supply and demand resources. Future research avenues point towards a methodology that can be used for assessing the potential impacts of research projects with low technology readiness outputs.