• 터널과지하공간
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• 제22권4호
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• pp.243-256
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• 2012

에너지의 효과적인 저장과 관리는 에너지 공급과 수요의 시간적 양적 불균형을 해소하고, 에너지 이용효율을 향상시킬 수 있다는 점에서 새로운 에너지원을 개발하는 일만큼 중요하다. 열에너지 저장 시스템은 산업폐열이나 태양열과 같은 열원 기반의 에너지를 저장하는 시스템으로서, 대용량 저장 시설에 암반 지하공동을 활용하는 경우 주변 암반의 낮은 열전달 특성과 높은 화학적 안정성을 통해 보다 효율적인 저장 시스템을 구축할 수 있다는 장점이 있다. 본 연구에서는 열에너지 저장 방식과 저장 매질의 일반적인 특성과 열에너지 저장사례에 대하여 살펴보고, 지하공동을 활용한 열에너지 저장 시스템에 대한 각 저장 매질의 적용성에 대해 개괄적으로 검토하였다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.141-146
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• 2008

For the efficient use of thermal energy and its related equipments, optimal energy in view of quality and quantity should be timely provided. The core of thermal energy storage technology deals with an energy efficiency for effective energy storage and supply. The relative importance of thermal energy storage technology has been underestimated so far, and the specific projects on this filed have been performed intermittently. For the efficient and systematic approach of the energy supply system projects on thermal energy storage technology, we conduct the survey on the current status of this field. Firstly, classify into the thermal energy storage and describing the recent research for each system. The necessity and importance of thermal energy storage technology is identified through this study. It reveals that the thermal energy storage is the mandatory technology to solve the difference of supply and demand in thermal loads. It would greatly contribute to the combined heat and power(CHP) system. The urgent technologies for the commercial value and the core technologies for the CHP system are classified with this study.

• 한국전기전자재료학회논문지
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• 제27권7호
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• pp.417-427
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• 2014

Renewable energy sources such as solar, wind and hydro provides utilizing renewable power and reduce the using fossil fuels. On the other hand, it is too critical to apply power system due to the intermittent nature of renewable energy sources, the continuous fluctuations of the power load, and the storage with high energy density. Energy storage system, including pumped-hydroelectric energy storage, compressed-air energy storage, superconducting magnetic energy storage, and electrochemical devices like batteries, supercapacitors and others have shown that solve some of the challenges. In this paper, we review the current state of applications of energy storage systems, and atomic layer deposition technology, graphene materials on the energy storage systems and processes.

• 한국초전도ㆍ저온공학회논문지
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• 제22권4호
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• pp.45-50
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• 2020

In this research, the variation of round-trip efficiency in a liquid air energy storage system (LAES) is calculated and an optimal configuration is found. The multiple stages of cold energy storage are simulated with several materials that process latent heat at different temperature ranges. The effectiveness in the charging and discharging processes of LAES is newly defined, and its relationship with the round-trip efficiency is examined. According to defined correlation, the effectiveness of the discharging process significantly affects the overall system performance. The round-trip efficiency is calculated for the combined cold energy storage materials of aqueous dimethyl sulfoxide (DMSO) solution, ethanol, and pentane theoretically. The performance of LAES varies depending on the freezing point of the cold storage materials. In particular, when the LAES uses several cold storage materials, those materials whose freezing points are close to room temperature and liquid air temperature should be included in the cold storage materials. In this paper, it is assumed that only latent heat is used for cold energy storage, but for more realistic analyzes, the additional consideration of the transient thermal situation to utilize sensible heat is required. In the case of such a dynamic system, since there is certainly more increased heat capacity of the entire storage system, the volume of the cold energy storage system will be greatly reduced.

• 터널과지하공간
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• 제22권1호
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• pp.1-11
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• 2012

열에너지 저장은 고온 또는 저온의 열에너지를 임시 저장하는 것으로서 에너지 수요와 공급 사이의 불균형을 줄일 수 있고, 이를 통해 에너지를 절약하고 에너지 이용효율을 향상시킬 수 있다. 특히 간헐적으로 에너지를 생산하는 신재생에너지의 경우 에너지 저장 장치와의 조합은 필수적이다. 또한 지하 암반의 낮은 열전도도와 높은 열용량을 이용하여 지하에 열에너지를 저장하는 경우 열손실을 최소화하여 추가적인 효율 향상이 기대된다. 본 고에서는 지하 열에너지 저장 기술을 조사 분석하고 스웨덴에 암반공동내 열에너지 저장 사례를 소개하였다.

• International Journal of Fluid Machinery and Systems
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• 제10권3호
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• pp.209-217
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• 2017

The paper presents two novel concepts of increasing the energy storage capacity at pumped storage power plants, both existing and new projects. The concepts utilize compressed air as a working medium to displace water from a volume originally not available for storage. The concepts are likely to give additional storage volume at a low cost, however, much development and many investigations are needed before the concepts can be shown to be technical and economical feasible solutions for energy storage. The concepts are disclosed so that researchers and utilities can start those investigations, hopefully helping the green transition by providing highly valuable energy storage for a future renewable energy having a much higher share of renewable energies than the current systems.

• 전기학회논문지
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• 제66권3호
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• pp.486-492
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• 2017

In recent years, renewable energy sources have been mentioned as solution to environmental regulation and energy supply-demand. Energy storage systems are needed to mitigate the intermittent output characteristics of renewable energy sources and to operate micro grid efficiently using renewable energy generation systems. However, despite the necessity of energy storage system, this cannot secure the economical efficiency of the energy storage system by high initial cost. In this paper, a micro grid is constructed to supply electric power to industrial customers by using solar power generation system and energy storage system among renewable energy generation power sources and operated to improve energy independence. In the case study, we use photovoltaic system which is representative renewable energy generation system. Unlike conventional photovoltaic system, this system uses floating photovoltaic system with the advantage of having high output and no land area limitations. It is operated for the purpose of improving energy independence in the micro grid. In order to secure economical efficiency, the energy storage system operates a micro grid with a minimum capacity. Finally, this paper calculates the appropriate subsidy for the energy storage capacity.

• 한국수소및신에너지학회논문집
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• 제29권3호
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• pp.251-259
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• 2018

Metal hydride based hydrogen storage under moderate temperature and pressure gives the safety advantage over the gas and liquid storage methods. Still solid-state hydrogen storage including metal hydride is below the DOE target level for automotive applications, but it can be adapted to stationary or miliary application reasonably. In order to develop a modular solid state hydrogen storage system that can be applied to a distributed power supply system composed of renewable energy - water electrolysis - fuel cell, the heat transfer and hydrogen storage characteristics of the metal hydride necessary for the module system design were investigated using AB5 type metal hydride, LCN2 ($La_{0.9}Ce_{0.1}Ni_5$). The planetary high energy mill (PHEM) treatment of LCN2 confirmed the initial hydrogen storage activation and hydrogen storage capacity through surface modification of LCN2 material. Expanded natural graphite (ENG) addition to LCN2, and compression molding at 500 atm improved the thermal conductivity of the solid hydrogen storage material.

• 한국수소및신에너지학회논문집
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• 제13권1호
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• pp.90-99
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• 2002

In order to utilize hydrogen energy in a large-scale in the future, development of effective hydrogen storage method is essentially required as well as that of efficient hydrogen production method. The hydrogen storage method using metal hydrides has been holding the spotlight as a safer and higher-density hydrogen storage method than conventional hydrogen storage methods such as liquid hydrogen or compressed hydrogen storage method. However when metals react with hydrogen to store hydrogen as metal hydrides, they undergo exothermic reactions, while metal hydrides evolve hydrogen by endothermic reaction. Therefore, hydrogen storage tank should have such structure that it can absorb or release reaction heat rapidly and efficiently. In this study, a review on the improvement of the heat release and absorption structure in the hydrogen storage tank was conducted, and as a result, a new type of hydrogen storage tank with the structure of vertical-type wall was designed and manufactured. Experimental results showed that this new type of tank could be used as an efficient hydrogen storage tank because its structure is simpler and manufacture is easier than cup-type hydrogen storage tank with the structure of packed horizontal cup.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.162.2-162.2
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• 2010

The energy storage system is considered to be one of the useful devices for energy storing and recycling. the energy storage system can save energy cost and stabilize the system voltage. This paper presents the development of two energy storage systems. One is 750V system for light rail system. the other is 1500V system for heavy rail system.