Abstract
The green hydrogen (H-2) technology has an important role to play in the European Union energy strategy towards decarbonization. Apart from traditional H-2 industrial usages, there is an increasing attention to its use in the heavy transport sector, in other energy-intensive industries, and in heating applications. Green H-2 production is planned to be based on renewable electricity generation and its production at an industrial scale may have a significant impact on the electricity markets. This research assesses the electricity cost of producing H-2 and its impact on the Iberian electricity market. Different evolution scenarios including a partially flexible H-2 demand, based on the Spanish and Portuguese energy and climate plans, have been considered for this assessment.

Abstract
Energy communities and self-consumption are considered as major drivers to achieve the decarbonization of the power sector, contributing to further increase the penetration of renewables, and empowering end consumers by turning them more active and flexible regarding electricity consumption. Considering the relevance of this topic and given that the corresponding legislation is recent, this paper summarizes the European Regulation on self-consumption and renewable energy communities and describes, analyses and compares its transposition to the Portuguese and Spanish national regulations. The main regulatory barriers for renewable energy communities' rollout are identified and regulatory improvements are proposed to overcome them.

Abstract
Transmission Expansion Planning (TEP) aims at identifying a list of new assets to be installed on the transmission grid to meet the long-term forecasted demand while ensuring a safe supply over the entire planning horizon. As TEP is a Mixed Integer Non-Linear Problem (MINLP) with a huge search space, in the last years several modern heuristic algorithms were proposed to deal with its challenging characteristics. In this way, this paper describes and evaluates the impact and implementation of four operators that can be easily incorporated in any evolutionary algorithm, namely: Neighborhood Search for Local Improvement (NSLI), Diversity Control (DC), Elitist Reproduction (ER) and Boundary Local Search (BLS). The impact of these operators is assessed and discussed over a hundred simulations using a traditional Genetic Algorithm (GA) and a well-known test system, the RTS 24-bus. Regarding the results, the NSLI and the BLS operator considerably improved the GA performance in solving the TEP problem regarding both the final value of the objective function and the diversity of solutions.

Abstract
This paper presents a heuristic algorithm to reduce the set of equipment candidates for Transmission Expansion Planning (TEP). Since it is a Constructive Heuristic Algorithm (CHA), the MiniEff algorithm aims at reducing the computational burden involved in the optimization process in a quick and satisfactory way. This approach includes two major blocks. The first one uses the minimum-effort calculation based on DC-OPF analysis to reduce the search space of the TEP problem. Then, the reduced list of investment alternatives is input to the AC-TEP formulation to build the final expansion plan using the Evolutionary Particle Swarm Optimization technique (EPSO). The tests on the developed TEP approach were done using the IEEE 118 Bus System and they demonstrate the gains that were obtained in terms of reducing the computer burden in solving TEP without compromising the quality of the final plans.

Abstract
In the last few decades, the vast majority of world states have faced increased energy consumption using more environmentally friendly production technologies. The use of traditional renewable energies like hydro, wind and solar has been the solution found. Despite this, new technical solutions and strategies are beginning to emerge, of which Floating Solar Photovoltaic (FSPV) systems are part. In this framework, southern European countries have excellent climate conditions for reinforcing the use of solar energy. This research assess the existing Portuguese potential for floating PV systems and its integration in the power grid. A floating solar power plant of 1MW in Gouvães dam included in the Tâmega hydroelectric complex, under construction in northern Portugal was sizing and evaluated its energy potential. A techno-economic feasibility study was also carried out taking into account the current investment costs and energy tariffs in the Iberian liberalized market. This integrated analysis allowed to obtain important results on the current state of the art, types of technologies available, their costs and the payback period for this type of projects.

Abstract
The operation of isolated power systems with 100% converter-based generation requires the integration of battery energy storage systems (BESS) using grid-forming-type power converters. Under these operating conditions, load dynamics influences the network frequency and voltage following large voltage disturbances. In this sense, the inclusion of induction motor (IM) load models is required to be properly considered in BESS power converter sizing. Thus, this paper presents an extensive sensitivity analysis, demonstrating how load modeling affects the BESS power converter capacity when adopting conventional control strategies while aiming to assure the successful recovery of all IM loads following a network fault. Furthermore, this work highlights that generators with converter interfaces can actively contribute to mitigate the negative impacts resulting from IM loads following a network fault. Thereby, two distinct control strategies are proposed to be integrated in the power electronic interfaces of the available converter-based generators: one to be adopted in grid-following converters and another one suitable for grid-forming converters. The proposed control strategies provide an important contribution to consolidating insular grid codes, aiming to achieve operational scenarios accommodating 100% penetration of converter-based generation with a significative percentage of the IM load composition without resorting to a significative increase in BESS power converter sizing.