• 신재생에너지
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• 제10권4호
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• pp.29-35
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• 2014

Non-used waste heat has recently been paid special attention due to several global warming regulation and energy cost rising. In this study, therefore, thermal energy storage system which uses a solid type heat media has been investigated about the possibility of heat accumulation and heat release for thermal energy storage system. 35kWh of bench-scale thermal storage system was used to investigate the characteristics of the solid type heat media. From the result, it is shown that a solid type heat media should be divided to supply constant heat to the customers' side. It is also shown the flow direction should be considered to reduce temperature difference between top and bottom sides in the thermal storage system.

• Journal of Power Electronics
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• 제18권4호
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• pp.1111-1126
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• 2018

In modern power systems, distributed generators (DGs) result in high stress on system frequency stability. Apart from the intermittent nature of DGs, most DGs do not contribute inertia or damping to systems. As a result, a new control method referred to as a virtual synchronous machine (VSM) has been proposed, which brought new characteristics to inverters such as synchronous machines (SM). DGs employing an energy storage system (ESS) provide inertia and damping through VSM control. Meanwhile, energy storage presents some physical constraints in the VSM implementation level. In this paper, a VSM mathematical model is built and analyzed. The dynamic responses of the output active power are presented when a step change in the frequency occurs. The influences of the inertia constant, damping factor and operating point on the ESS volume margins are investigated. In addition, physical constraints are proposed based on these analyses. The proposed physical constraints are simulated using PSCAD/EMTDC software and tested through RTDS experiment. Both simulation and RTDS test results verify the analysis.

• 한국수소및신에너지학회논문집
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• 제34권5호
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• pp.389-397
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• 2023

This study compares domestic and foreign research on renewable energy-based water electrolysis clean hydrogen. Domestic studies from 2010 to 2023 focused on technological efficiency, energy efficiency, and system efficiency, with few analyzing infrastructure and technology trends. Overseas research initially focused on technological efficiency and stability, but has since shifted to economic and environmental impact, policy effectiveness, industry-university-research cooperation, and sustainability. To improve water electrolysis technology production, this study suggests prioritizing technology stability over efficiency, resolving government regulations and resident acceptance issues, promoting industry-university-institute cooperation for rapid commercialization of research results, and developing a strategy for sustainable development of renewable energy-based water electrolysis technology.

• 신재생에너지
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• 제20권1호
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• pp.26-37
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• 2024

Renewable energy sources play a key role in achieving carbon neutrality and zero net emissions in the power generation sector. Various efforts have been made to support the deployment of renewable energy, particularly solar photovoltaic and wind power, including policies to internalize the external cost of carbon emissions. In this study, we conducted a financial analysis of a 800 MW floating photovoltaic system and compared it with ground solar power generation. Additionally, we conducted a cost-benefit analysis that included the social cost of carbon. The findings showed that the floating photovoltaic project can meet the profitability target through an appropriately designed internalization of the social cost of carbon.

• 신재생에너지
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• 제10권3호
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• pp.22-30
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• 2014

The isolated self-generating electricity with diesel engine generator has been used in islands far away from main land. It costs high because of increasing oil price, and unsafe to have supplying oil and its related components by ship due to unexpectable marine conditions. Therefore there is the need for the hybrid system of renewable energy like wind or solar energy systems with oil engine generator, which can reduce oil use and extend oil supplying period. In this study, the feasibility of such hybrid system with smart micro grid on the eight islands of Jeon-nam province is surveyed to find good place for the demonstration test of the hybrid system. In each island, 3 wind turbine systems of 10 kW and photovoltaic of 20 kW are tested with already installed diesel engine. The performance and costs of the hybrid system in each island are compared in the given conditions of solar and wind energy potential. As a result of the study, Jung-ma island is recommended for the optimum place to make real field demonstration test of isolated hybrid generating and smart grid systems.

• 한국인터넷방송통신학회논문지
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• 제21권2호
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• pp.137-142
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• 2021

태양광발전 가로등은 태양광에너지를 사용하여 2차전지에 충전 후 램프를 통해 야간조명에 활용하는 시스템으로서 부하 단 LED 가로등을 설치하여 독립형 또는 계통연계형으로 구성할 수 있다. 태양전지모듈을 통해 발전된 에너지는 충방전 제어장치를 통해 2차전지에 충전 후 일사량 감시에 따른 발전전압과 충전전압의 비교, 또는 일몰, 일출 후 특정시간 설정으로 LED 가로등을 점등 소등을 할 수 있다. 따라서 이러한 내용을 기반으로 본 논문에서는 신재생에너지 활용 및 저장기능을 이용한 교육용 모의 태양광발전 가로등 설계 및 제작을 통해 대학의 학생들에게 1) 태양광을 포함한 신재생에너지를 이용하여 전기에너지로 활용하는 에너지 변화의 흐름 이해, 2) 신재생에너지 이해 및 관련 제품의 기초설계와 제작 응용력 함양, 3) 전력변환을 통한 신재생에너지 활용과 하드웨어 제작을 통한 실습과 분석력 강화를 심어줄 수 있다.

• 한국지리정보학회지
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• 제15권3호
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• pp.81-90
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• 2012

최근 신재생에너지 자원에 대한 사회적인 관심 증대와 맞물려 IT(Information Technology) 기술과 공간정보기술의 급속한 발전에 따라 신재생에너지 분야에서도 GIS(Geographic Information System) 공간정보 분석 기술과의 융합을 통하여 체계적이고 과학적인 활용 방법들이 많이 연구되고 있다. 본 연구에서는 정확한 지형, 경제, 문화적 환경 요소들을 종합적으로 고려한 정확하고 정밀한 풍력에너지 시설물 적지분석 시스템 모듈 개발과 동시에 3차원 GIS 등과 같은 최신 공간 정보기술을 활용하여 정밀한 현장정보 구현과 3차원 결과물 표출, 3차원 객체 구현, 모의 등 풍력 신재생에너지 관련 종합정보를 관리할 수 있는 3차원 Web GIS 기반 풍력에너지 시설물 적지분석 시스템을 개발하였다. 이를 통하여 과학적인 신재생에너지 시설물 단지 조성과 함께 정확하고 정량적인 정보 수집, 관리, 분석이 가능할 뿐만 아니라 실시간 정보제공체계 구축의 전환점을 마련할 수 있었으며 3차원 영상기반 신재생에너지 자원정보 관리시스템 구축을 통한 다양한 현장정보 분석이 가능함으로써 합리적 의사결정 지원을 할 수 있게 되었다.

• 신재생에너지
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• 제5권1호
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• pp.32-39
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• 2009

Availability of reliable and affordable energy supply is a prerequisite for economic growth. Renewables are the third largest contributor to global electricity production after coal and natural gas and account for a share of 18%. Power generating capacity from renewables has increased to around 900GW by the year 2007. Today biodiesel fuels have been in commercial use in many countries and recently the world-wide biodiesel market has experienced considerable growth, which is partly due to various tax concession programs and other financial incentives. In Korea, biodiesel has already been used for transportation fuel, but not used for power generation fuel yet Korean government has a strategy for renewable energy propagation, especially the goal of power generation amount by renewable energy is 3% of total power production by 2012. This paper focuses on the feasibility study for adaptability and strategy of using biodiesel as power generation fuel. The study also has the plan to replace the fuel of thermal power plant, gas turbine and distributed power system. As the increase of biodiesel fuel, I look forward to environment-friendly power generation and the strategy of Renewable Portfolio Standards(RPS).

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.75.2-75.2
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• 2011

국내 유인도서의 상당수는 전력의 대부분을 디젤발전으로 생산한다. 향후 발전설비의 교체 혹은 증설이 있을 경우 신재생에너지원 설비의 보급 여지가 있다. 이에 본 연구는 울릉도에 화력발전 설비만을 증설했을 경우와 이를 신재생에너지복합시스템 설비로 대체했을 때의 경제적 타당성을 비교분석한다. 우리는 복합발전 시스템을 풍력터빈, PV, 소수력발전 등의 신재생에너지 설비, Batteries, Converter와 같은 보조전원, 저장 및 back up을 위한 flywheel과 Diesel generator등으로 구성했다. 분석에 사용한 HOMER(Hybrid Optimization for Energy Renewable)는 신재생에너지복합 발전시스템 분석에 사용되며 결과를 NPC(Net Present Cost)의 오름차순으로 제시하여 발전설비구성의 조합들 중 최적의 시나리오를 보여준다. 분석결과 울릉도의 경우 신재생에너지복합 발전의 보급이 잠재적으로 가능할 것으로 보인다. 또한 계통운영의 기술적인 측면을 감안할 경우 정밀한 분석이 가능할 것이다. 따라서 본 연구는 계통운영과 경제성분석 연구의 연계를 위한 사전연구로써 그 의미를 갖는다.

• 디지털산업정보학회논문지
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• 제12권3호
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• pp.231-257
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• 2016

Several efforts to replace the use of existing fossil energy resources have already been made around the world. As a result, a new industry of renewable energy has been created, and efficient energy distribution and storage has been promoted intensively. Among the newly explored renewable energy sources, the most widely used one is solar energy generation, which has a high market potential. An energy storage system (ESS) is a system as required. In this paper, the design and implementation of an ESS for the efficient use of power in stand-alone street lights is presented. In current ESS applied to stand-alone street lights, either 12V~24V DC (from solar power) or 110V~220V AC (from commercial power) is used to recharge power in systems with lithium batteries. In this study, an ESS that can support both solar power and commercial power was designed and implemented; it can also perform emergency recharge of portable devices from solar powered street lights. This system can maximize the scalability of ESSes using lithium batteries with efficient energy conversion, with the advantage of being an eco-friendly technology. In a ripple effect, it can also be applied to smart grids, electric vehicles, and new, renewable storage markets where energy storage technology is required.