Abstract
Over the last decades, district heating has been under development, especially the technologies like heat pumps, solar thermal and cogeneration. However, there is still a long way to go regarding regulation, legislation and market liberalization, which varies across countries and regions. The objective of this work is to investigate the potential benefits of decentralized district heating systems in residential areas. By studying a case study of EnergyLab Nordhavn, a residential area in Copenhagen, Denmark, the paper compares the market outcomes of decentralized systems such as community markets to the centralized pool market currently in practice, under the EMB3Rs platform. The study focuses on key market outputs such as dispatched production, revenues, and daily consumption patterns. Additionally, the paper examines the impact of advanced features such as flexible heat consumption and network awareness in the market. The results of this research suggest that decentralized district heating systems have the potential to improve market outcomes and increase energy efficiency in residential areas.

Abstract
Recently, the uptake of renewable energy has surged in distribution networks, particularly due to the costeffectiveness and modular nature of photovoltaic systems. This has paved the way to a new era of user engagement, embodied by individual and collective self-consumption, and promoted by the EU Directive 2018/ 2001, which advocates for the establishment of Renewable Energy Communities. However, the transposition of this directive varies across Member States, resulting in specific rules for each country. In this work, the impact that different energy sharing models have on the same community is quantitatively assessed. The policy analysis focuses on the regulation of two countries, Italy and Portugal, chosen for the specular ways in which their models operate, respectively virtually and physically. The analysis is supported by a suite of tools which includes two optimization problems for community's operations, one for each analysed regulation, and a set of consumer protection mechanisms, to ensure no member is losing money while in community. Results demonstrate that the sharing model impacts community's optimal operations, optimal battery size and configuration, and members' benefit. As these models are sensitive to different variables, personalized interventions at national level are required.

Abstract
The integration of renewable generation requires new sources of flexibility, including the flexibility from distributed resources that can be unlocked via local flexibility markets (LFMs). In these markets, aggregators (AGGs) offer the flexibility from their portfolios to the flexibility requesting parties (FRP), i.e. system operators or other balancing requesting parties. To bid in LFMs and manage market uncertainty, AGGs must compute the flexibility they are willing to offer at each possible flexibility market price, by optimizing their portfolios. This paper proposes a 2-stage methodology to compute the flexibility bidding curve that an energy community can send to a LFM when behaving as an AGG of its members resources. At stage 1, the energy community (EC) manager computes the optimal EC operation without flexibility provision, minimizing the EC energy bill, and serving as the baseline to verify the flexibility provision. Then, at stage 2, for each possible flexibility price, the EC manager computes the optimal flexibility to be offered, minimizing the EC energy bill but including the flexibility provision incomes, to build the flexibility bidding curve.

Abstract
Self-consumption regulations are leading to the emergence of new business models proposed by new players and causing traditional players to make new proposals to take advantage of the new business opportunities. In this context, traditional retailers are assessing self-consumption business models, offering management services for self-consumption structures, or the installation of distributed resources, such as solar panels or batteries. Some of the new business models being proposed by electricity suppliers are related to virtual battery services. Indeed, suppliers can, in the free retail market, create innovative tariffs, and design them to make their customers believe they own and manage a battery, even if it does not correspond to a physical battery in the grid. This paper analyses the business model of a supplier offering a virtual battery service, comparing it to the installation of a physical battery, showing that it has no significant benefits compared to more simple approaches.

Abstract
This research examines the impact of the COVID-19 pandemic and the Ukraine-Russia conflict on Portugal and Spain's national energy and climate plans. Both countries have updated their plans in response to these events, emphasizing energy efficiency, renewable energy investment, and circular economy principles. Portugal focused on addressing energy poverty and digitalization, while Spain accelerated its energy transition to align with the European Green Deal. Additionally, the Ukraine-Russia conflict prompted measures to enhance energy security and NECPs in both countries. Through a semi-systematic literature review spanning 2020-2023, our study analyzes how these global events shaped national energy and climate plans. The case studies of Portugal and Spain highlight the importance of flexibility and resilience in crafting sustainable energy strategies during such a complex crisis.

Abstract
The relationship between hydrogen and electricity has gained attention due to their interconnected roles in the energy transition. Existing joint electricity and hydrogen market models often overlook the dependence between electricity and hydrogen prices. Indeed, while electrolyzers production can raise electricity prices, electricity price significantly impacts the costs of hydrogen production. Considering this price-based interdependency, this study compares a Cournot equilibrium and a perfect competition market model for electricity and hydrogen integration. Both models are transformed into new quadratic optimization problems to facilitate resolution. The analysis highlights the potential of the Iberian region for hydrogen production. Furthermore, it is evident that, under conditions of perfect competition, renewable generation is given priority for meeting electricity demand, leading to a decrease in both electricity and hydrogen prices on a global scale compared to the Cournot scenario.