Investigating the wind parks location impact on the failure rate of contemporary wind turbines

Wind energy is currently an established electricity production option worldwide, contributing to the reduction of environmental pollution and CO2 emissions. Actually, during the last twenty years a considerable installed wind power increase has been encountered, thus the up to date installed wind power approaches 550GWe. The situation in Greece is fairly well since the current wind power in operation is approximately 2700MWe. As it is well established, the reliability of the wind turbines influences both the energy production and the maintenance and operation cost of commercial wind parks. As a result, the operational period of the machine is reduced, while additional expenses are needed in order to face the downtime causes. In the present work operational data of an important number of wind parks located in Greece have been analyzed. Moreover, emphasis is given on the impact that the wind parks' location has on the failures of commercial wind turbines. For this purpose real world data concerning similar wind parks, based on the same type of wind turbines, located on the mainland, on the islands or near the sea have been collected and analyzed. According to the data gathered one may compare the different failure patterns of contemporary commercial wind turbines operating for up to ten years all around Greece

Investigating the wind parks location impact on the failure rate of contemporary wind turbines

Wind energy is currently an established electricity production option worldwide, contributing to the reduction of environmental pollution and CO2 emissions. Actually, during the last twenty years a considerable installed wind power increase has been encountered, thus the up to date installed wind power approaches 550GWe. The situation in Greece is fairly well since the current wind power in operation is approximately 2700MWe. As it is well established, the reliability of the wind turbines influences both the energy production and the maintenance and operation cost of commercial wind parks. As a result, the operational period of the machine is reduced, while additional expenses are needed in order to face the downtime causes. In the present work operational data of an important number of wind parks located in Greece have been analyzed. Moreover, emphasis is given on the impact that the wind parks' location has on the failures of commercial wind turbines. For this purpose real world data concerning similar wind parks, based on the same type of wind turbines, located on the mainland, on the islands or near the sea have been collected and analyzed. According to the data gathered one may compare the different failure patterns of contemporary commercial wind turbines operating for up to ten years all around Greece

Wave energy exploitation in the Ionian Sea Hellenic coasts: spatial planning of potential wave power stations

Wave energy represents the ‘new entry’ to Renewable Energy Sources discussion, in the context of clean and sustainable energy solutions in the electricity production sector. This research describes a geo-spatial Multiple-Criteria Decision Analysis, based on the Geographic Information Systems technology, for the identification of the best location to deploy a potential Wave Energy Farm in the Ionian Sea, an area offshore the Greek mainland West coast. For this purpose, several factors are taken into consideration; restrictions such as protected areas, military exercise areas etc. and weighted factors such as distance to power grid, wave height etc. The wave resource assessment is completed through real data measurements and numerical wave model approximations. The results pinpoint the most suitable areas for installing the proposed wave power plants, i.e. near the SW coast of Corfu, in the West side of the Straits between Kefallonia and Zakynthos and near the broader area of Pylos, in the SW coast of Peloponnesus. The suggested methodology can be equally applied in other spatial planning cases too, being considered as a checklist, addressed to policy-makers and private investors

Wind turbine wake models' evaluation for different downstream locations

The land use limitations, especially for onshore applications, have led modern Wind Turbines (WTs) to be aggregated in wind parks under the scope of minimizing the necessary area required. Within this framework, the trustworthy prediction of the wind speed deficiency downstream the WTs' hub (known also as the “wake effect”) and the meticulous wind park micrositing are of uppermost importance for the optimized WTs siting across the available land area. In this context, substantial effort has been made by the academic and research community, contributing to the deployment of several analytical, numerical and semi-empirical wake models, attempting to estimate the wind speed values at different locations downstream a WT. The accuracy of several semi-empirical and analytical wake models, serving also as the basis for pertinent commercial software development, is investigated in the present work, by comparing their outcome with experimental data from a past research work that concerns the wake flow. The dimensionless streamwise distance (known also with the term “downstream distance”) from the WT's hub is used as benchmark in order to categorize and evaluate the calculation results. A dedicated comparison between the wind speed cases investigated is conducted, striving to properly assess the wake models' prediction accuracy. The notable findings obtained for the wake models examined designate the requirement for subsequent research to enlighten the wake effect dynamic behavior

Clean energy solution for remote islands. The case of Nisyros island

The extended fossil fuel reserves’ depletion and the pertinent environmental issues are considered as the principal traits of the contemporary power generation schemes. The Aegean Archipelagos comprises of numerous dispersed islands, with most of them using autonomous oil-based power stations in order to satisfy their energy requirements. To cope with the aforementioned problems in a sustainable way, a substantial shift to Renewable Energy Sources (RES) applications is examined. The present work investigates the sustainable solutions that can be implemented in Nisyros island to enhance its energy autonomy. To this end, RES-based configurations have been introduced for both the power generation and the transportation sectors. The feasibility of these clean energy solutions renders possible their implementation in relevant remote regions

PV Temperature Prediction Incorporating the Effect of Humidity and Cooling Due to Seawater Flow and Evaporation on Modules Simulating Floating PV Conditions

The temperature prediction for floating PV (FPV) must account for the effect of humidity. In this work, PV temperature prediction for steady-state Tpv and transient conditions Tpv(t) incorporates the effect of humidity and cooling due to seawater (s.w.) splashing and evaporation on PV modules. The proposed formulas take as main inputs the in-plane solar irradiance, wind speed, ambient temperature, relative humidity (RH), and s.w. temperature. The transient effects of s.w. splashing and the evaporation of the s.w. layer from the module are theoretically described considering the layer’s thickness using Navier–Stokes equations. Tpv and Tpv(t) measurements were taken before and after s.w. splashing on c-Si modules at the seashore and inland. PV temperature predictions compared to measured values showed very good agreement. The 55% RH at the seashore versus 45% inland caused the Tpv to decrease by 18%. The Tpv(t) at the end of the s.w. flow of 50–75 mL/s/m on the module at the seashore was 35–51% lower than the Tpv inland. This Tpv(t) profile depends on the s.w. splashing, lasts for about 1 min, and is attributed to higher convection, water cooling, and evaporation on the modules. The PV efficiency at FPV conditions was estimated to be 4–11.5% higher compared to inland

Assessing Renewable Resources at the Saronikos Gulf for the Development of Multi-Generation Renewable Systems

Decarbonisation of any energy system implies that more renewables will have to be incorporated into the grid. This requires a thorough assessment of available resources to properly estimate potential contributions and identify opportunities. This work focuses on the Saronikos Gulf, which is part of the most crowded urban coastline in Greece. Solar, wind and wave resources are analysed, and the long-term characteristics affecting power production are discussed. Solar resources provide ≥250 Wh·m−2 with small long-term changes. Wind resources at coastal and onshore regions are ≥50 W·m−2; however, it has higher annual volatility. Finally, the wave resources of the region are from 130 to 170 W/m with a positive resource rate of change ≈2.5 W·m−1/year. It is expected that multi-generation by different resources, especially with temporal overlaps of wind and waves, will reduce intermittent production, hence accelerating the energy transition.Offshore Engineerin

Energy analysis of a Hybrid Wind-Wave Solution for Remote Islands

The energy needs of most Aegean islands are covered by the operation of autonomous/local power stations (APS/LPS) using imported oil. The costly operation of the APS/LPS combined with the resulting environmental problems, set the issue of a sustainable and rational energy solution mainly for the remote islands, showing respect to the sensitive island ecosystems and the acceptance of local communities. In this context, high wind speeds as well as the remarkable wave potential of the Aegean Archipelagos could be the driving force for a sustainable energy supply solution for these islands by exploiting combined energy sources along with an appropriate energy storage system, comprising a modern hybrid renewable based station. Moreover, the exploitation of wave energy is one of the future priorities of the European Union (Blue Growth) in an effort to support the installation of wave energy converters, which are in the final stage of technological development. The proposed analysis examines the combined exploitation of the wave and wind potential for a representative medium sized island of the Aegean Archipelagos in order to cover its electrical needs. The results show that the installation of a hybrid power station contributes to a higher integration of RES into an autonomous micro-grid and that the stochastic production of wind turbines can be counterbalanced due to the smoother (time-dependent) production of wave systems. In addition, the ability to store excess renewable energy enhances the energy supply security of an island micro-grid providing a clean energy solution for the remote Aegean island communities and thus reducing their oil dependence.Offshore Engineerin