Techno-economic analysis of high potential offshore wind farm locations in Turkey

The wind energy market is rapidly growing in Turkey which made it one of the top three countries in Europe, and the seventh in the world, in terms of wind power capacity addition in 2016. Turkey has high onshore and offshore wind power potential which is widely distributed across the country. However, there has been no offshore wind farm (OWF) in operation in Turkey. This paper performs a comprehensive techno-economic analysis of OWF projects in three of the most promising wind locations (namely, Bozcaada, Gokceada, and Bandirma). The optimal OWF sites are selected by applying a multi-criteria site selection method to Turkey's coastal regions. Technical analysis consists of annual energy production estimation using the Virtual Wind Farm model and development of various electrical system design topologies for the proposed OWF projects. A detailed economic feasibility analysis is then conducted using a discounted cash flow economic model that considers current Turkish renewable energy support schemes under various discount rates. Taking the OWF investor's perspective, this study accounts for the key economic indicators which are used in the decision-making processes. The results of various model runs are compared to determine the best options for the proposed OWF investments to be profitable. It is shown that the proposed OWF projects are economically feasible only in the case of meeting certain techno-economic conditions. The radial electrical design is proved to be the most cost-effective option. Among the proposed projects, the Bozcaada OWF appears to be the best investment option with a levelized cost of electricity (LCOE) of $81.85–109.55 per MWh while the Bandirma OWF is the least economically viable with an LCOE of$100.73–135.97 per MWh. The findings are extrapolated to suggest feasible recommendations for the investors and policy makers which will help to shape the offshore wind energy outlook of Turkey

Pitfalls in MR Imaging of Musculoskeletal Tumors

WOS: 000331281400008PubMed ID: 24515883A wide range of musculoskeletal tumors and tumor-like conditions may be encountered when patients undergo radiologic examinations. Although MR imaging is a powerful medical imaging method that has been used extensively in the evaluation of musculoskeletal tumors, nontumoral or tumorlike lesions may have similar imaging findings. The imaging features of certain normal, reactive, benign neoplastic, inflammatory, traumatic, or degenerative processes in the musculoskeletal system may mimic malignant tumors. Misinterpretation of the imaging findings can lead to inappropriate clinical management of the patient. We review and describe the MR imaging characteristics of nontumoral bone lesions that are located in the marrow cavity, cortical bone, or in both, and soft tissue lesions that may be misinterpreted as sarcoma

Offshore wind power potential of the Black Sea region in Turkey

Majority of the studies on offshore wind power potential assessment is limited to the examination of the wind speed only. This study examines the offshore wind power potential of the Black Sea coastal region in Turkey based on location selection criteria including territorial waters, military areas, civil aviation, shipping routes, pipelines and underground cables, social, and environmental concerns. Wind Atlas Analysis and Application Program (WAsP) is used to do the statistical analysis of wind speed and wind direction data for 20 locations in the Black Sea coastal region. WAsP results are then elaborated based on the location selection criteria for better assessment of offshore wind power utilization. The study reveals that there are limited numbers of locations for offshore wind power generation in the Black Sea region in spite of its long coastline. Moreover, there is a high need for a zoning change for Amasra shores in order to utilize high offshore wind power potential of Amasra. Our finding suggests that location selection criteria other than wind speed should definitely be considered for better assessment of the wind power potential of a region

PV reactive power injection effect on voltage profile

With the growing number of Distributed Generators (DGs) in power systems, demand to utilize Photovoltaic (PV) systems has also shown increase. PV systems are equipped with PV inverters in order to convert DC power to AC power. PV inverters are great sources to improve voltage profile in the utility grid using their reactive power injection feature. On the other hand, the current standards do not allow inverters to inject reactive power, which would be the case in the future and it needs to be investigated. This paper analyzes voltage profiles of IEEE 13 nodes distribution network when PV inverters provide reactive power. Power flow analyses are conducted for various combinations of PV grid interconnections; for fixed PV generation and load profiles and fluctuating PV generation and load profiles. PowerWorld simulations reveal the effect of reactive power injections to the grid as a case study for the distribution network. Results show that reactive power injection improves the voltage profile of the IEEE 13 node system but the size of PV systems should be kept within certain limits to prevent overvoltages in the network

The Resonance Analysis Caused by Harmonics in Power Systems Including Thyristor Controlled Reactor

The static VAR compensators having fixed capacitor thyristor controlled reactor (FC-TCR) used to improve voltage stability in power systems are nonlinear elements. The fixed capacitor group will produce reactive power while the thyristor controlled reactor will consume reactive power in compensators having FC-TCR. Changing the firing angles of TCR provides the reactive power variation of the system since the reactive power production of capacitors is fixed at a determined voltage level. In some cases, the variation of these firing angles will cause the harmonics in the system. In this study, TCR\u27s are discussed to be harmonic sources and the resonance case caused by harmonics has been investigated with Fourier Matrix Model and MATLAB Software