Abstract
This paper proposes a methodology using Hybrid Control System (HS) to manage the integration of Variable Renewable Electricity Sources (VRES). The HS define a combination of discrete and continuous signals, in this case, discrete by Pump-Hydro-Storage (PHS) and continuous performance is the Wind Power (WP). The coupling of Wind Power and PHS to produce a dispatchable power output could be a significant benefit to those in an energy trading system. Improving VRES prediction reduces system dispatch errors, however does not give total economic opportunities to the generator. Increased dispatchable backup power generation can improve the system's ability to handle deviations of WP, as verified when the proposed approach is applied to Brazilian and Portuguese power system. © 2018 IEEE.

Abstract
This paper proposes a near to real-time local market to provide reactive power to the transmission system operator (TSO), using the resources connected to a distribution grid managed by a distribution system operator (DSO). The TSO publishes a requested reactive power profile at the TSO-DSO interface for each time-interval of the next delivery period, so that market agents (managing resources of the distribution grid) can prepare and send their bids accordingly. DSO resources are the first to be mobilized, and the remaining residual reactive power is supplied by the reactive power flexibility offered in the local reactive market. Complex bids (with non-curtailability conditions) are supported to provide flexible ways of bidding fewer flexible assets (such as capacitor banks). An alternating current (AC) optimal power flow (OPF) is used to clear the bids by maximizing the social welfare to supply the TSO required reactive power profile, subject to the DSO grid constraints. A rolling window mechanism allows a continuous dispatching of reactive power, and the possibility of adapting assigned schedules to real time constraints. A simplified TSO-DSO cost assignment of the flexible reactive power used is proposed to share for settlement purposes.

Abstract
In recent years, traditional power systems have undergone a significant transition, mainly related to the massive penetration of renewable generation. More specifically, the transformation of residential consumers into prosumers has been challenging the existing operation of the electricity market. This transition brings new challenges and opportunities to the power system, leading to new business models. One widely discussed change is related to a consumer-centric or prosumer-driven approach, promoting increased participation of small consumers in power systems. The present paper aims at discussing the recent business models as enablers of the increasing prosumers' role. To do so, it defines the main features of prosumers and their related regulation as well as possible market designs within power systems. In addition, it discusses enabling technologies to properly create the conditions that sustain new prosumer-driven markets. Then, it presents a comprehensive review of existing and innovative business models and a discussion on their future roles in modern power systems. Moreover, a set of recommendations for promoting these business models in the power system is provided. An important conclusion is that, even though economically possible, not all innovative business models can spread around the world due to regulatory obstacles.

Abstract
EU-SysFlex H2020 project aims at developing and testing innovative tools for the integration of high levels (above 50%) of renewable energy sources (RES) in the pan-European Electricity system. Those high levels of RES will increase the need for new sources of flexibility to support the system services, since there will be a decreasing number of conventional power plants connected to the grid, traditionally the main providers of these services. In this context, this study describes the Flexibility Hub (FlexHub) concept, part of the EU-SysFlex Portuguese demonstrator, consisting of a platform of tools managed by the distribution system operator to facilitate market-based flexibility provision to the transmission system operator (TSO) using resources connected to the distribution system. The FlexHub includes the provision of active power flexibility to the TSO (with an extended restoration reserve market concept), an essential tool to help the TSO balancing the grid, being a replicable concept that will become increasingly relevant in a future with a high share of decentralised assets connected to the distribution grids.

Abstract
This work performs a comparative analysis of battery energy storage system (BESS) participation in the multi-services electricity market, considering the optimal operating cost and better profitability for the BESS portfolios. A comparison of the application of these portfolios in different market conditions is proposed: (i) energy-only market, (ii) reserve-only market, (iii) sequential energy and reserve market, and (vi) joint energy and reserve market. For each BESS portfolio, hourly strategies for buying and selling offers are proposed, to maximize the revenue, accounting for the expected load and generation variations in the grid. The analysis of the BESS strategies is carried out through a case study based on actual generation data, where operating costs and BESS flexibility are assessed. One conclusion is that, even though, BESS makes a profit by participating in single markets, the best strategy is to participate in both energy and reserve markets, especially in the presence of a joint energy and reserve market model.

Abstract
Hydrogen is regarded as a flexible energy carrier with multiple applications across several sectors. For instance, it can be used in industrial processes, transports, heating, and electrical power generation. Green hydrogen, produced from renewable sources, can have a crucial role in the pathway towards global decarbonization. However, the success of green hydrogen production ultimately depends on its economic sustainability. In this context, this work evaluates the economic performance of a hydrogen power plant participating in the electricity market and supplying multiple hydrogen consumers. The analysis includes technical and economical details of the main components of the hydrogen power plant. Its operation is simulated using six different scenarios, which admit the production of either grey or green hydrogen. The scenarios used for the analysis include data from the Iberian electricity market for the Portuguese hub. An important conclusion is that the combination of multiple services in a hydrogen power plant has a positive effect on its economic performance. However, as of today, consumers who would wish to acquire green hydrogen would have to be willing to pay higher prices to compensate for the shorter periods of operation of hydrogen power plants and for their intrinsic losses. Nonetheless, an increase in green hydrogen demand based on a greater environmental awareness can lead to the need to not only build more of these facilities, but also to integrate more services into them. This could promote the investment in hydrogen-related technologies and result in changes in capital and operating costs of key components of these plants, which are necessary to bring down production costs.