This study focuses on analyzing the energy-saving effects of the recirculation aquaculture system using seawater source heat pumps and solar power generation. Based on the thermal load analysis conducted using the transient system simulation tool, the annual energy consumption of the recirculation aquaculture system was analyzed and the energy-saving effects of utilizing the photovoltaic system was evaluated. When analyzing the heat load, the sea areas where the fish farms are located, the type of breeding tank, and the circulation rate of breeding water were taken into consideration. In addition, a method for determining the appropriate capacity for each operation time was examined when applying the energy storage system instead of the existing diesel generator as an emergency power, which is required to maintain the water temperature of breeding water during power outage. The results suggest that, among the four seas considered, Jeju should be estimated to achieve the highest energy-saving performance using the solar power generation, with approximately 45% energy savings.

Numerous studies have attempted to predict the energy output of solar-powered vehicles based on different parameters such as road conditions, driver characteristics, and weather. However, since these studies were conducted on stationary vehicles, they are limited in their accuracy when applied to driving vehicles. This study aimed to improve the accuracy of electric power prediction for a solar-powered bus by applying a technique that improves energy efficiency without affecting driving performance. A comparative analysis of power generation and solar irradiance data was conducted for the bus driven on different roads to forecast its power generation, and a high-accuracy power generation prediction equation was derived. A comparison with actual test results revealed that a power generation forecast accuracy of at least 90% was achieved, validating the equation used for forecasting. With this power generation prediction process, it is possible to forecast the amount of energy generated in advance when a solar bus is operated in a specific area.

This study analyzes the effects of the number of angles and bends on resistance in a conductor-embroidered stitch circuit for efficient power transfer through a conductor of wearable energy harvesting to study changes in power lost through connection with actual solar panels. In this study, the angle of the conductive stitch circuit was designed in units of 30°, from 30° to 180°, and the resistance was measured using an analog Discovery 2 device. The measured resistance value was analyzed, and in the section of the angle where the resistance value rapidly changes, it was measured again and analyzed in units of 5°. Following this, from the results of the analysis, the angle at which the tension was applied to the stitch converges was analyzed, and the resistance was measured again by varying the number of bends of the stitch at the given angle. The resistance decreases as the angle of the stitch decreases and the number of bends increases, and the conductor embroidery stitch can reduce the loss of power by 1.61 times relative to general embroidery. These results suggest that the stitching of embroidery has a significant effect on the power transfer in the transmission through the conductors of wearable energy harvesting. These results indicate the need for a follow-up study to develop a conductor circuit design technology that compares and analyzes various types of stitches, such as curved stitches, and the number of conductors, so that wearable energy harvesting can be more efficiently produced and stored.

The global power generation industry is becoming a key power generation industry with gas power generation and renewable energy solar power generation. This research aims to focus on solving two problems as a method to improve the solar light collection efficiency among fixed variable deformation methods. Maintaining the proper temperature of the water injection device through automatic temperature detection to solve efficiency degradation, and establishing an automatic operation system by finding the optimal angle for each season, are intended to derive a value that can represent the optimal power generation.

선박으로부터 발생하는 온실가스 배출을 저감하기 위한 규제가 점차 강화되고 있다. 현존선에서도 EEXI(Energy Efficiency Existing Index)가 도입되었으며 이와 같은 온실가스 배출 감축목표를 달성하기 위해 다양한 연구가 진행되고 있다. 본 연구에서는 국제항 해에 종사하는 현존선 중 자동차운반선에 태양광 발전시스템을 적용하여 연료유 사용량을 줄임으로써 온실가스 배출이 저감될 수 있는 시스템을 제안하였다. 제안된 태양광 발전시스템은 태양광 모듈, 에너지저장시스템, 전력변환장치 등으로 구성되었으며, 본 시스템의 적 용 가능성을 확인하기 위해 전력전자프로그램을 통해 시스템을 모델링하였으며, 시뮬레이션을 실시하였다. 또한, 실제 선박에 적용하기 위한 타당성 검증을 위해 경제성 분석을 실시하였으며, 약 11년 이후 경제성 부분에서도 유의미한 결과가 도출됨을 확인할 수 있었다.

대한민국의 낚시산업은 레저활동을 즐기는 인구 증가로 인해 매년 급성장하고 있으며 이에따라 규모가 큰 9-10톤급 낚시어선 의 수는 매년 늘어나고 있다. 현재 운항 중인 낚시어선은 낚시 활동 중 유류비 절감과 엔진 발생 소음 저감을 위해 엔진을 정지하고 배터리를 이용하여 선박의 필수장비를 운영하고 있다. 하지만 배터리의 방전으로 인한 엔진 시동불량 등으로 인해 해상에서 표류되는 사고가 매년 꾸준히 발생하고 있으며, 이는 대형 인명사고로 이어질 수 있다. 본 연구에서는 낚시어선의 안전확보를 위해 태양광 보조전원 설치를 제안하고, 9-10톤급 선박을 대상으로 선정하였다. 대상선박의 태양광 발전설비 공간 확보 가능성을 확인하였으며, 태양광 발전설비의 적용을 검증하기 위해 조업 중 필요한 필수 부하량을 계산하고 전력분석프로그램을 통해 태양광 발전시스템을 모델링하였다. 모델링 된 태양광 발전시스템에 우리나라의 월별 수평면 평균 일사량을 적용하여 낚시어선의 태양광 보조발전장치 적용에 관한 타당성을 입증하였다.

타워형 집광태양열발전의 핵심요소인 헬리오스타트는 경량화를 통한 설비비 저감이 매우 중요한다. 반사판 면적 16m2의 기 존 헬리오스타트 대비 샌드위치 패널을 사용하여 무게를 50% 경량화한 헬리오스타트의 풍하중 평가를 수행하였다. 반사판이 수직, 45 도 경사인 경우에 대해 전산유체역학 해석을 하여 반사판에 작용하는 풍압을 산정하고 구조해석을 수행하여 최대응력의 발생부위 및 반사판의 변위에 의한 반사각도의 이격을 계산하였다. 45도 경사진 반사판이 바람이 불어오는 반대편으로 향한 경우가 바람을 마주보 는 배치보다 최대 풍하중이 더 크게 나타났으며, 반사판 풍하측으로의 유동박리에 의한 후류의 발달도 반사판의 배치에 따라 매우 상 이한 형태를 보였다. 경량화 모델의 경우 반사판 구동을 위한 기어의 배치를 변경하여 핵심 지지체인 기둥의 강성을 확보할 필요가 있 음을 확인하였다.

Solar energy has been known as a successful alternative energy source, however it requires a large area to build power generation facilities compared to other energy sources such as nuclear power. Weather factors such as rainy weather or night time impact on solar power generation because of lack of insolation and sunshine. In addition, solar power generation is vulnerable to external elements such as changes in temperature and fine dust. There are four seasons in the Republic of Korea hereby variations of temperature, insolation and sunshine are broad. Currently factors that cause find dust are continuously flowing in to Korea from abroad. In order to build a solar power plant, a large area is required for a limited domestic land hereby selecting the optimal location for the plant that maximizes the efficiency of power generation is necessary. Therefore, this research analyze the optimal site for solar power generation plant by implementing analytic hierarchy process based on weather factors such as fine dust. In order to extract weather factors that impact on solar power generation, this work conducts a case study which includes a correlation analysis between weather information and power generation.

In photovoltaic power generation where minority carrier generation via light absorption is competing against minority carrier recombination, the substrate thickness and material quality are interdependent, and appropriate combination of the two variables is important in obtaining the maximum output power generation. Medici, a two-dimensional semiconductor device simulation tool, is used to investigate the interdependency in relation to the maximum power output in front-lit Si solar cells. Qualitatively, the results indicate that a high quality substrate must be thick and that a low quality substrate must be thin in order to achieve the maximum power generation in the respective materials. The dividing point is 70 μm/5 × 10−6 sec. That is, for materials with a minority carrier recombination lifetime longer than 5 × 10−6 sec, the substrate must be thicker than 70 μm, while for materials with a lifetime shorter than 5 × 10−6 sec, the substrate must be thinner than 70 μm. In substrate fabrication, the thinner the wafer, the lower the cost of material, but the higher the cost of wafer fabrication. Thus, the optimum thickness/lifetime combinations are defined in this study along with the substrate cost considerations as part of the factors to be considered in material selection.

In this paper we describe differential circuit of charge pump for voltage management systems, their evolution and improvement in design. The systems are powered by solar cells and generate different voltage levels which are suitable for systems on-chip integrated regulator applications. The voltage regulator outputs voltage from low power digital circuit, -2V for memory, and from 2V to 12V for input and output components. The circuits were simulated using LT SPICE software.

This paper presents a development process of a forecast and monitoring system for a photovoltaic (PV) solar plant. PV solar system is one of sustainable resource of energy. So, Korean government encourages businessmen to build a PV solar plant. Renewable Portfolio Standard (RPS) system is one of encouraging policies. Most RPS businessmen use monitoring system for a PV solar plant and they need an accurate forecast of power generation for business purpose. Therefore we propose an estimating algorithm of power for a PV solar plant using weather forecast. Proposed algorithm is implemented in a forecast and monitoring system and it works better than existing estimating methods.

We have investigated the structural and electrical properties of Ga-doped ZnO (GZO) thin films deposited by anRF magnetron sputtering at various RF powers from 50 to 90W. All the GZO thin films are grown as a hexagonal wurtzitephase with highly c-axis preferred parameters. The structural and electrical properties are strongly related to the RF power. Thegrain size increases as the RF power increases since the columnar growth of GZO thin film is enhanced at an elevated RFpower. This result means that the crystallinity of GZO is improved as the RF power increases. The resistivity of GZO rapidlydecreases as the RF power increases up to 70W and saturates to 90W. In contrast, the electron concentration of GZO increasesas the RF power increases up to 70W and saturates to 90W. GZO thin film shows the lowest resistivity of 2.2×10−4Ωcmand the highest electron concentration of 1.7×1021cm−3 at 90W. The mobility of GZO increases as the RF power increasessince the grain boundary scattering decreases due to the reduced density of the grain boundary at a high RF power. Thetransmittance of GZO thin films in the visible range is above 90%. GZO is a feasible transparent electrode for application asa transparent electrode for thin film solar cells.

환경오염에 대한 관심이 높아지고 새롭게 고조됨에 따라, 에너지 관련해서도 대체에너지 이용에 관한 연구가 부각되고 있다. 신 재생에너지라고 불리는 대체에너지는 무공해, 무한정의 다양한 자연에너지의 특성과 이용기술을 활용하여 화석연료를 사용하는 기존에너지를 대체하는 에너지이다. 이러한 대체에너지 중 풍력 및 태양에너지는 그 자원이 무한정이며 환경에 미치는 영향이 거의 없이 이용할 수 있다. 두 발전시스템은 상호 보완적으로 연계된 발전시스템으로 통상적으로 조합되어 운용되어진다. 본 논문에서는 일정기간의 풍속, 풍향, 계절 등의 기상 조건의 변화에 따른 데이터를 분석하여 목포해안지역에서 경제적이고 효율적인 복합발전시스템의 적용가능성을 제안해 보고자 한다.

해상에서 운용되는 일점계류형 해양플랜트의 태양광 발전 시스템은 독립 전원 체계를 가지고 있으며, 해상 환경, 부조일수 등의 영향으로 안정적인 전력을 공급하는 것이 중요하다. 이러한 이유로 태양광 패널을 여러 방향으로 설치하게 되는데, 이 때 각 패널마다 입사되는 광량이 달라지므로 부분음영현상이 발생하게 된다. 육상용 태양광 발전시스템의 발전량은 위도의 영향을 받으므로 우리나라의 경우 30~36° 사이의 각도로 설치하는 것이 일반적이나, 일점계류형 해양플랜트에 설치되는 태양광 발전 시스템의 경우 부분 음영 현상에 의해 최대전력점이 제어 가능 범위 밖에 존재하는 경우가 발생하게 되고 이는 전력 발전 손실이 된다. 이 때 두 패널의 광량차이를 줄임으로써, 최대 전력점을 MPPT 알고리즘이 추종 가능한 범위에 존재하게 하여 발전 효율을 더 높일 수 있으며, 시뮬레이션 결과 설치각도 20°에서 가장 높은 발전 효율 가짐을 확인하였다.

The whole world concentrates on the reduction of greenhouse gas to effectively cope with policy toward global climate change. To effectively react to climate change, even the agricultural sector requires construction of new farming systems that utilizes new and renewable energy because of rising oil prices and regulations for greenhouse gas emissions. For this reason, we need to fuse the new and renewable energy with the horticulture sector of which the light and heat energy cost accounts for great part, moreover, efforts and researches should me done which can increase income of farmers through reducing carbon dioxide and energy cost in agricultural production expenses. Therefore, this study analyzes economic feasibility and applicability of fusing geothermal heat pump and solar power facilities with high-tech glass greenhouse. As a result, it is concluded that there surely are an applicability and economic feasibility if we apply new development system that can be an alternative for problems of securing premises of existing geothermal heat pump and the RPS system as a power generation company in case of solar power. Therefore, using this analysis data, if new empirical studies fusing and implementing agriculture sector with new and renewable energy fields proliferate and be applied to actual rural and agricultural field, it will increase actual income and will become a new advanced agricultural system that effectively deals with world-wide environmental problems.