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- Exploring the offshore wind and wave generation complementarity in Portugal for a sustainable and resilient power systemPublication . Couto, António; Justino, Paulo Alexandre; Costa, Paula Silva; Simões, Teresa; Estanqueiro, AnaABSTRACT: Exploring variable energy sources generation complementarity can, among several benefits, help in the reduction of the negative impacts of variability from individual sources, and lower the system’s flexibility requirements. This study focuses on the complementarity between offshore wind and wave energy aiming to identify its overall value to the power system. Using Portugal as a case study, this work examines two offshore regions of the Plan for the Allocation of Offshore Renewable Energy in Portugal using standard approaches to assess the level of complementarity. The findings show a clear seasonal mismatch in the summer between wind and wave energy, which supports their complementary nature and helps smooth out seasonal fluctuations in offshore renewable generation. The results indicate that wave energy brings value to diversifying the offshore energy mix. When compared with onshore renewable generation, the combined use of offshore wind and wave power significantly enhances the stability of energy supply, reduces extreme events, which can contribute to decrease the need for additional system flexibility in future nearly 100% renewable-based power systems.
- Renewable Energy Production in the Mediterranean: Exploring the Potential for Offshore Wind DevelopmentPublication . Simões, Teresa; Tsami, Maria; Nieto, Felix; Huvaj, NejanABSTRACT: This study presents an overview of the current state of the Maritime Spatial Planning among the Mediterranean countries, explores the previous studies on evaluating the offshore wind potential of the Mediterranean region along with the criteria for suitable site selection. Based on a review of the current state of offshore renewable energy, the potential locations offshore wind will be explored for the Mediterranean coastline case study area. The research concludes with a set of critical considerations related to the need for proper synergies establishment among different stakeholders and for cultivating social acceptance and community engagement. The analysis aims to support decision-makers evaluating the potential of the Mediterranean coastal area in supporting the energy transition goal.
- Satellite-based offshore wind data close to the coast: comparison with onshore meteorological mast records and microscale CFD simulationsPublication . Álvarez, Antonio J.; Snæbjörnsson, Jónas Þór; Couto, António; Simões, Teresa; Poozesh, Poorya; Félix, NietoABSTRACT: Satellite observation of environmental phenomena is becoming increasingly accurate, complementing pre-existing measurement techniques. In this work, the offshore wind field recorded by Sentinel-1 on February 6th, 2021, close to the Southwestern Iceland coast is compared with the anemometric measurements provided by a relatively dense network of weather stations in the Reykjanes peninsula and microscale CFD simulations that use the Hvassahraun weather station data to approximate wind velocity and direction in offshore locations. The three methodologies show a good agreement in the 10-minute velocity magnitudes for the set of considered offshore locations, while the 10-minute mean wind direction shows certain scattering, although with a consistent prevalence of Eastern wind directions, in agreement with the anemometric data. The results show obvious complementarities among the three approaches, suggesting further studies to improve accuracy, especially for capturing local effects impacting wind magnitude and directionality.
- Contribution to the development of a new value chain in the marine renewable energy sectorPublication . Fontes, Margarida; Simões, Teresa; Estanqueiro, Ana; Nieto, Felix; Tsami, MariaABSTRACT: As part of the commitments made in the NECP2030 for Portugal, an increase in wind capacity is planned, including an additional 10.4 GW onshore and 2 GW offshore. In this sense, it is necessary to assess the conditions for the creation of a new industrial value chain that will accelerate this development and offer attractive conditions for the involvement of the industrial sector, providing conditions for the objectives recommended in the NECP 2030 to be met. Projects OffshorePlan - Planning for the Use of Offshore Renewable Energies in Portugal, and OceanTrans - Ocean energy technologies transformative potential analyzed the relevant socio-economic component for this sector, namely the process of creating a new industrial value chain to support the development of marine renewable energies. As part of this research, a questionnaire survey was conducted targeting companies in sectors with complementary skills and resources, directly or indirectly related to the development of projects in this area. The questionnaire yielded 114 responses from companies already active and 182 from companies willing to become involved in the future. The results allowed us to obtain a global view of the actual and potential involvement of the industrial sector, as well as to gain some insight into how companies view the requirements to operate in this area and the main barriers to their performance. This article presents the main findings obtained in the scope of this research and discusses their contribution to the advancement of the marine renewable energy sector and, as such, to the development of offshore wind energy in Portugal.
- Optimized Planning Framework for Radial Distribution Network Considering AC and DC EV Chargers, Uncertain Solar PVDG, and DSTATCOM Using HHOPublication . Bonela, Ramesh; Tripathy, Sasmita; Roy Ghatak, Sriparna; Swain, Sarat Chandra; Lopes, Fernando; Acharjee, ParimalABSTRACT: This study aims to provide an efficient framework for the coordinated integration of AC and DC chargers, intermittent solar Photovoltaic (PV) Distributed Generation (DG) units, and a Distribution Static Compensator (DSTATCOM) across residential, commercial, and industrial zones of a Radial Distribution Network (RDN) considering the benefits of various stakeholders: Electric Vehicle (EV) charging station owners, EV owners, and distribution network operators. The model uses a multi-zone planning method and healthy-bus strategy to allocate Electric Vehicle Charging Stations (EVCSs), Photovoltaic Distributed Generation (PVDG) units, and DSTATCOMs. The proposed framework optimally determines the numbers of EVCSs, PVDG units, and DSTATCOMs using Harris Hawk Optimization, considering the maximization of techno-economic benefits while satisfying all the security constraints. Further, to showcase the benefits from the perspective of EV owners, an EV waiting-time evaluation is performed. The simulation results show that integrating EVCSs (with both AC and DC chargers) with solar PVDG units and DSTATCOMs in the existing RDN improves the voltage profile, reduces power losses, and enhances cost-effectiveness compared to the system with only EVCSs. Furthermore, the zonal division ensures that charging infrastructure is distributed across the network increasing accessibility to the EV users. It is also observed that combining AC and DC chargers across the network provides overall benefits in terms of voltage profile, line loss, and waiting time as compared to a system with only AC or DC chargers. The proposed framework improves EV owners' access and reduces waiting time, while supporting distribution network operators through enhanced grid stability and efficient integration of EV loads, PV generation, and DSTATCOM.
- Dynamic Line Rating Models and Their Potential for a Cost-Effective Transition to Carbon-Neutral Power SystemsPublication . Estanqueiro, Ana; Algarvio, Hugo; Couto, António; Michiorri, Andrea; Salas, Sergio; Pudjianto, Danny; Hagglund, Per; Dobschinski, Jan; Bolgaryn, Roman; Kanefendt, Thomas; Gentle, Jake; Alam, S. M. Shafiul; Priest, Zachary M.; Abboud, Alexander W.ABSTRACT: Most transmission system operators (TSOs) currently use seasonally steady-state models considering limiting weather conditions that serve as reference to compute the transmission capacity of overhead power lines. The use of dynamic line rating (DLR) models can avoid the construction of new lines, market splitting, false congestions, and the degradation of lines in a cost-effective way. DLR can also be used in the long run in grid extension and new power capacity planning. In the short run, it should be used to help operate power systems with congested lines. The operation of the power systems is planned to have the market trading into account; thus, it computes transactions hours ahead of real-time operation, using power flow forecasts affected by large errors. In the near future, within a "smart grid" environment, in real-time operation conditions, TSOs should be able to rapidly compute the capacity rating of overhead lines using DLR models and the most reliable weather information, forecasts, and line measurements, avoiding the current steady-state approach that, in many circumstances, assumes ampacities above the thermal limits of the lines. This work presents a review of the line rating methodologies in several European countries and the United States. Furthermore, it presents the results of pilot projects and studies considering the application of DLR in overhead power lines, obtaining significant reductions in the congestion of internal networks and cross-border transmission lines.
- Strategic Bidding to Increase the Market Value of Variable Renewable Generators in New Electricity Market DesignsPublication . Algarvio, Hugo; Sousa, VivianABSTRACT: Electricity markets with a high share of variable renewable energy require significant balancing reserves to ensure stability by preserving the balance of supply and demand. However, they were originally conceived for dispatchable technologies, which operate with predictable and controllable generation. As a result, adapting market mechanisms to accommodate the characteristics of variable renewables is essential for enhancing grid reliability and efficiency. This work studies the strategic behavior of a wind power producer (WPP) in the Iberian electricity market (MIBEL) and the Portuguese balancing markets (BMs), where wind farms are economically responsible for deviations and do not have support schemes. In addition to exploring current market dynamics, the study proposes new market designs for the balancing markets, with separate procurement of upward and downward secondary balancing capacity, aligning with European Electricity Regulation guidelines. The difference between market designs considers that the wind farm can hourly bid in both (New 1) or only one (New 2) balancing direction. The study considers seven strategies (S1-S7) for the participation of a wind farm in the past (S1), actual (S2 and S3), New 1 (S4) and New 2 (S5-S7) market designs. The results demonstrate that new market designs can increase the wind market value by 2% compared to the optimal scenario and by 31% compared to the operational scenario. Among the tested approaches, New 2 delivers the best operational and economic outcomes. In S7, the wind farm achieves the lowest imbalance and curtailment while maintaining the same remuneration of S4. Additionally, the difference between the optimal and operational remuneration of the WPP under the New 2 design is only 22%, indicating that this design enables the WPP to achieve remuneration levels close to the optimal case.
- Strategies to Incentivize the Participation of Variable Renewable Energy Generators in Balancing MarketsPublication . Algarvio, Hugo; Sousa, VivianABSTRACT: Balancing markets (BMs) play a crucial role in ensuring the real-time equilibrium between electricity demand and supply. The current requirements for participation in BMs often overlook the characteristics and capabilities of variable renewables, limiting their effective integration. The increasing penetration of variable renewables necessitates adjustments in the design of BMs to support the transition toward carbon-neutral power systems. This study examines the levels of active market participation for a wind power producer (WPP) in the Iberian Electricity Market and the Portuguese BMs. In addition to exploring current market dynamics, the study tests one methodology proposed by the Danish Transmission System Operator to support the participation of variable renewables in BMs, the P90, and two new methods based on the full cost balancing concept. These methodologies incentivize WPPs to minimize imbalances by allowing market participation only if imbalances remain within a 10% deadband of annual hours (P90), hourly offers (D90), or both (DP90). The results indicate that participating in the secondary capacity market, particularly for downward capacity, is the most profitable strategy. This participation enhances the value of wind power by over 42%. However, in most methodologies, the WPP failed to deliver nearly 100% of its allocated capacity approximately 1% of the time. In contrast, the D90 approach limited the maximum deviation to 10%, demonstrating the highest reliability among the evaluated methods.
- Strategic Bidding to Increase the Market Value of Variable Renewable Generators in Electricity MarketsPublication . Sousa, Vivian; Algarvio, HugoABSTRACT: The 2050 global ambition for a carbon-neutral society is increasing the penetration of the most competitive variable renewable technologies, onshore wind and solar PV. These technologies are known for their near-zero marginal costs but highly variable time-dependent generation. Power systems with major penetrations of variable generation need high balancing flexibility to guarantee their stability by maintaining the equilibrium between demand and supply. Electricity markets were designed for dispatchable technologies. Support schemes are used to incentivize and de-risk the investment in variable renewables, since actual market designs are riskier for their active participation. This study presents three strategic bidding strategies for the active participation of variable renewables in electricity markets based on probabilistic quantile-based forecasts. This case study examines the levels of active market participation for a wind power producer (WPP) in the Iberian electricity market and the Portuguese balancing markets, where WPPs are financially responsible for imbalances and operate without support schemes in the first and second stages of the Iberian market designs. Results from this study indicate that the WPP has the potential to increase its market value between 36% and 155% if participating in the tertiary and secondary balancing markets completely adapted to its design, respectively. However, considering the use of strategic bidding in actual market designs, by participating in the secondary reserve, the WPP can increase its market value by 10% and 45% when compared with perfect foresight and operational cases, respectively.
- Pre-Solve Methodologies for Short-Run Identification of Critical Sectors in the ACSR Overhead Lines While Using Dynamic Line Rating Models for Resource SustainabilityPublication . Algarvio, HugoABSTRACT: Most transmission system operators (TSOs) use seasonally static models considering extreme weather conditions, serving as a reference for computing the transmission capacity of power lines. The use of dynamic line rating (DLR) models can avoid the construction of new lines, market splitting, false congestions and the degradation of lines in a cost-effective way. The operation of power systems is planned based on market results, which consider transactions hours ahead of real-time operation using forecasts with errors. The same is true for the DLR. So, during real-time operation TSOs should rapidly compute the DLR of overhead lines to avoid considering an ampacity above their lines' design, reflecting the real-time weather conditions. Considering that the DLR of the lines can affect the power flow of an entire region, the use of the complete indirect DLR methodology has a high computation burden for all sectors and lines in a region. So, this article presents and tests three pre-solve methodologies able to rapidly identify the critical sector of each line. These methodologies solve the problem of the high computation burden of the CIGR & Eacute; thermodynamic model of overhead lines. They have been tested by using real data of the transmission grid and the weather conditions for two different regions in Portugal, leading to errors in the computation of the DLR lower than 1% in relation to the complete CIGR & Eacute; model, identifying the critical sector in significantly less time.