Serkan Abbasoglu

Miniarutized and lightweight automotive antenna design for vehicle to vehicle communication

In this paper, automotive antenna design for vehicle to vehicle communication is proposed. Antenna design is based on elliptical geometry by utilizing the self-similarity of the fractal concepts. The initiator is an elliptical shape based vertical to horizontal ratio of about 3:1. The proposed antenna is a combination of two reproduced elliptical shape placed at +/- 30 degrees to the central point of the initiator. Antenna is miniaturized (42 × 34 mm2) and lightweight with efficient characteristics. Simulation results show that the presented antenna has a reflection coefficient characteristic better than -17.5 dB, 70% radiation efficiency, 4-6dBi antenna gain and omni-directional radiation pattern properties over the 75 MHz of 802.11p standard (5.85 - 5.925 GHz).

Evaluation of Wind–Solar Hybrid System for a Household in Northern Cyprus

The sustainable power generation industry needs a balance between efficiency and cost in order to be competitive to the more conventional energy sources (i.e., fossil fuels) to produce energy. The cost reduction will help to increase production and provide new developments in technological and manufacturing areas. In the following study, the grid connected PV–wind hybrid systems are analyzed to find out the optimum number of PV panels and wind turbine capacity to generate electricity for a household in Nicosia, Northern Cyprus (NC). Firstly, meteorological conditions of NC and required power load are investigated. Then, HOMER software is used to optimize the size, capacity, and the number of each of the components. This analysis is done with the evaluation of economical indicators such as Net Present Value, Simple Payback Period, and Save to Investment Ratio for the hybrid system to produce adequate electricity for the desired load. Also, greenhouse gas mitigation due to the use of PV–wind hybrid system instead of conventional fossil fired plants is calculated and discussed.

Economic feasibility of replacing sodium vapor and high pressure mercury vapor bulbs with LEDs for street lighting

ABSTRACT The main aim of this article is to examine the feasibility of an energy audit program. LEDs are used to replace the sodium vapor lamps and high-pressured mercury vapor lamps that are currently used for the street lighting system in the Turkish Republic of Northern Cyprus. 44% of the fossil fuels imported into the Turkish Republic of Northern Cyprus is used for electricity generation, which makes the reduction in the consumption of electicity very important. This project will save as much as 36,880,410 kWh on site annually and 111,758,818 kWh from the source. The economic, environmental, and fossil fuels savings of this project are also evaluated.

Performance analysis and comparison of photovoltaic, solar water heating and photovoltaic thermal systems

The aim of this study is to review photovoltaic systems, solar water heating systems and photovoltaic-thermal system, in order to understanding the principles of operation of a hybrid PVT system. The main objective of this review is to evaluate the techno-economic performance of a hybrid photovoltaic-thermal system (PVT) and compare with that of a separate performance of PV and SWH systems. A case study is carried out which considers installation of 31 kW PVT system in the climatic conditions of Cyprus. One major advantage of PVT systems over PV and SWH is the area used for installation; the PVT system produces nearly same amount of energy on half of the area that PV and SWH covers. It is found that the annual electricity production of these systems are, 54,209 kWh, and 57,207 kWh/yr., for PVe and PVTe, respectively, where PVe refers to merely PV system and PVTe refers to PV system with Thermal part. On the other hand, the production of hot water heating systems is 159, 867 kWh/yr. and 149,148 kWh/yr. for mere SWH and thermal part of PVT, respectively. The economic analysis shows that the PV+T is slightly more feasible in terms of SPP, SIR and IRR with a value of 2.8 years, 6.8 and 30% respectively, compared to the PVT system with 2.9 years, 6.5 and 28%, respectively.

Thermal Energy storage for solar power plant applications

As awareness of global warming and its adverse effects as caused by human activities increases in the world, renewable energy is fast gaining popularity as a way of combating the “energy trilemma” i.e. meeting requirements for environmental sustainability, energy security and energy equity. (WEC, 2015) The sun is the primary source of renewable energy with the exception of geothermal energy. Solar energy utilization is however limited due to intermittency of the resource. Solar thermal power plants employ solar radiation as the heat source to produce steam to drive turbines and produce electricity. Solar Thermal Energy (STE), unlike other solar energy conversion technologies, offers potential for storage of excess energy produced, for later use. This is a sure way of increasing operation hours and thus capacity to produce power. The paper reviews thermal energy storage systems and shows that the storage material is the main driving force in system design considerations.

Dynamic bandwidth allocation in a reconfigurable and converged access network

In this paper, we propose a reconfigurable and converged optical access network architecture with dynamic bandwidth allocation. The network proposes the co-existence of long term evolution (LTE), wireless interoperability for microwave access (WiMax) and ultra-wide band (UWB) technologies. LTE is considered for next generation mobile telephony, WiMax is designed mainly for data transmission. In addition, UWB could be used for high definition (HD) audio and video communication applications. All technologies are generated by using VPI transmission Maker and simulated with 16 QAM modulation schemes. All the signals qualities are investigated with the error vector magnitudes (EVMs). LTE/WiMax/UWB over single mode fibre (SMF) is examined and maximum limit are achieved at 76km with an EVM of -18.2dB, 58km with an EVM of -25dB and 65km with an EVM of -19dB for LTE, WiMax and UWB respectively. It is also realized that the chromatic dispersion needs to be compensated for long transmission systems (above 100km).

Multi-band and miniaturized antenna design for ultra wide band applications with band rejection characteristic

In this paper, the combination of concentric square loop and the Koch curve fractal geometries based microstrip antenna design for ultra wideband (UWB) applications is presented. This fractal structure is implemented on a empty square. Three progressively concentric square loop is applied inside the empty square and a full square is applied to the center for the first iteration. Then, a Koch curve fractal is applied to the lines of the first iteration. The proposed antenna is miniaturized (44 × 43 mm2) and has multi-band characteristics. Simulation results show that the presented antenna has a reflection coefficient characteristic <; -15dB, 80% radiation efficiency, 4-6dBi antenna gain and omni-directional radiation pattern properties over the full UWB bandwidth (3.1 - 10.6 GHz) while showing the band-rejection performance in the frequency band of 4.75-6.75 GHz.