Abstract
The buildings' energy consumption increasing requires solutions to improve their energy efficiency, thus reducing the electricity bill's associated costs. This paper aims to study the load profiles of a service building and its optimization to reduce the costs related to electricity consumption. The electrical load profiles are analyzed, and the electrical equipment and its consumption are characterized. Moreover, to increase energy efficiency and reduce energy costs, a renewable energy system based on photovoltaic panels is sized and integrated into the building. The analysis of the building's consumption profiles allowed the PV system's dimensioning to eliminate power peaks, enabling a reduction in the contracted power. The results demonstrate the effectiveness of the proposed solution, resulting in a reduction of the electricity bill.

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
In the coming years, many countries are going to bet on the exploitation of offshore wind energy. This is the case of southern European countries, where there is great wind potential for offshore exploitation. Although the conditions for energy production are more advantageous, all the costs involved are substantially higher when compared to onshore. It is, therefore, crucial to maximize system efficiency. In this paper, an optimization model based on a Mixed-Integer Linear Programming model is proposed to find the best wind turbines location in offshore wind farms taking into account the wake effect. A case study, concerning the design of an offshore wind farm, were carried out and several performance indicators were calculated and compared. The results show that the placement of the wind turbines diagonally presents better results for all performance indicators and corresponds to a lower percentage of energy production losses.

Abstract
Bidirectional electric vehicle charging stations (EVSE) offer new business models to users and can provide ancillary services to the electrical grid. During charging operation EMC standards and during discharging grid codes are applicable. In this study the harmonic emissions including the total harmonic distortion (THD) and total distortion demand factor (TDD) together with the grid impedance up to 2 kHz of a 10 kW bidirectional charging station are analyzed. While harmonic emission measurements of EVSE at laboratory conditions gives results for idealized conditions and field tests strongly depend on local grid conditions, the real-life operation of an EVSE at a well-known reconstructed grid gives valuable information about the harmonic behavior and impact to the grid impedance. The results show that the bidirectional EVSE can be a main pollutant of harmonic emissions at low power set-points, harmonic phase angle can change from inductive to capacitive behavior and the first resonance frequency of the grid impedance is moved to lower frequencies.

Abstract
Bidirectional electric vehicle charging stations (EVSE) offer new business models like Demand Response to users or can provide ancillary services to support the electrical grid (V2G and G2V). This type of charging station represents a novelty in the electrical grid, as it is considered as load and as power generation unit at the same time. In this study the supraharmonic emissions of a bidirectional EVSE are analyzed at a reconstructed electrical distribution grid. The emissions are determined according to existing standards (IEC61000-4-7 and IEC61000-4-30) for different grid conditions and operating points. Influence factors for supraharmonic emissions are identified as well as narrowband and wideband emissions of the EVSE. Time-domain analysis of the high-frequency signals which can lead to equipment malfunction concludes this work and emphasizes the need of regulations in this frequency range.

Abstract
With a still high rate of use of energy from non-renewable sources, it is crucial that new energy generation solutions are adopted to reach greenhouse gas reduction targets. The integration of renewable energy sources in buildings is an interesting solution that allows reducing the need for energy from the power grid, contributing to a significant increase in the energy efficiency of buildings. The main aim of this paper is to evaluate the impact that the aerodynamics of the buildings in particular the roof shape has considering the integration of wind energy systems. The results of Computational Fluid Dynamics (CFD) simulations are presented in order to identify the effect of the two roof shapes on energy production by wind turbines (WT). For this purpose, the factor matrices (FM) that gives information about the wind profile around the building taking into account the building's roof profile were calculated. Comparing the results for the wind flow obtained by the FM and the CFD simulations for the flat and gabled roofs, similarities are observed for them, allowing to conclude that the CFD analysis results in a methodology with great accuracy for the aerodynamic study of buildings roof shape.