• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.981-987
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• 2017

In this paper, we estimate the economic benefits of Energy Storage Systems (ESSs) for peak load shaving in an urban railway substation using the annual cost. The annual investment cost of ESSs is estimated using Net Present Value (NPV) and compared with the cost reduction of electricity by the ESS. The optimal capacities of the battery and Power Converting System (PCS) are determined for peak load shaving. The optimal capacity of the ESS and the peak load shaving is determined to maximize the profit by the ESS. The proposed method was applied to real load data in an urban railway substation, and the results show that electric power costs can be reduced. Other aspects of the ESS, such as the lifetime and unit price of the battery, are also investigated economically.

• 한국산업융합학회 논문집
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• 제21권5호
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• pp.207-217
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• 2018

Recently, the importance of energy demand management, particularly peak load control, has been increasing due to the policy changes of the Second Energy Basic Plan. Even though the installation of distributed generation systems such as Photovoltaic and energy storage systems (ESS) are encouraged, high initial installation costs make it difficult to expand their supply. In this study, the power consumption of a university building was measured in real time and the measured power consumption data was used to calculate the optimal installation capacity of the Photovoltaic and ESS, respectively. In order to calculate the optimal capacity, it is necessary to analyze the operation methods of the Photovoltaic and ESS while considering the KEPCO electricity billing system, power consumption patterns of the building, installation costs of the Photovoltaic and ESS, estimated savings on electric charges, and life time. In this study, the power consumption of the university building with a daily power consumption of approximately 200kWh and a peak power of approximately 20kW was measured per minute. An economic analysis conducted using these measured data showed that the optimal capacity was approximately 30kW for Photovoltaic and approximately 7kWh for ESS.

• 품질경영학회지
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• 제49권2호
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• pp.161-170
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• 2021

Purpose: The purpose of this study was to evaluate the economic value of installing public Energy storage system (ESS) facilities using a logit regression analysis and Contingent Valuation Method (CVM). We focused mainly on the environmental benefits of ESS and analyzed how the users' attitude toward environmental protection and knowledge of renewable energy affect their Willingness to pay (WTP) Methods: A single-bounded dichotomous choice (SBDC) survey was used to collect the data. We asked participants whether they are willing to pay a randomly presented cost (KRW 100, 500, 1000, 1500, 2000, 2500, 5000, 10000) along with their attitude to toward environmental protection, knowledge of renewable energy, and perceived cost of electric bill. 417 valid samples were collected and used for the analysis. Results: The results of the logit regression show that the initial bid, attitude toward environmental protection, knowledge of renewable energy, and perceived cost of electric bill significantly affect the user's WTP of public ESS facilities. The CVM results show that users are willing to pay KRW 5,049.1/month to install ESS facilities. Conclusion: : According to results, we conclude that the users agree with the need to install ESSs and that environmental benefits of ESSs are important factors for ESS adoption. Therefore, policy makers need to emphasize environmental aspects to install the ESS facilities.

• 에너지공학
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• 제25권2호
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• pp.94-100
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• 2016

에너지저장장치(ESS)는 전력수급 불균형 해소, 신재생에너지의 출력안정, 주파수 조정용 등 전력공급 안정성 향상 및 효율적 전기에너지사용 등에 기여하는 중요자원으로, 전세계적으로 '23년까지 '14년 설치용량의 약 30배가 증가한 55.9GWh의 보급이 전망되고 있다. 이와 같이 급증하는 세계시장에서 국내 ESS 업계의 경쟁력 확보를 위해서는 자국내 설치실적(Track Record) 확보가 필요한데, 우리나라는 주파수 조정용(FR용(用))과 그간 지속되어 왔던 전력수급 불균형 상황에 대비하기 위한 부하이동용 중심으로 ESS를 보급하여 왔다. 하지만, 주파수 조정용의 경우 통상적으로 화력발전소 정격용량의 약 5% 범위에서 설치효용이 발생하는 것으로 평가되고 있어, 화력발전이 비약적으로 증가하지 않는 한 국내 시장의 확장성이 부족하다고 할 수 있으며, 여유로운 예비력 확보정책에 따라 부하이동용에 대해서도 보급필요성이 저하되고 있는 바, 새로운 방식의 보급확대 대상이 필요하다고 할 수 있다. 유망한 신규보급대상은 간헐적 출력의 약점은 있으나, 신기후체제 대응과 산업육성을 위해 지속적으로 추진예정인 신재생에너지와의 연계설치를 통해 신재생에너지의 출력을 안정화 하고, 신재생에너지 발전량의 계통투입시기 조절을 통한 이산화탄소 저감효과를 기대할 수 있는 분야라고 할 수 있다. 본 연구에서는 향후 에너지정책의 최대 화두인 신기후체제 대응을 위한 온실가스 감축수단을 활용할 수 있도록, 태양광 연계형 ESS 충방전모드를 온실가스 저감효과를 고려토록 설계한 후, 투자유도를 위한 REC 가중치 산정방법에 대한 정책대안을 제시하였다.

• 전기학회논문지
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• 제64권1호
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• pp.1-7
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• 2015

This paper proposes probabilistic reliability evaluation model of power system considering Wind Turbine Generator(WTG) integrated with Energy Storage System(ESS). Monte carlo sample state duration simulation method is used for the evaluation. Because the power output from WTG units usually fluctuates randomly, the power cannot be counted on to continuously satisfy the system load. Although the power output at any time is not controllable, the power output can be utilized by ESS. The ESS may make to smooth the fluctuation of the WTG power output. The detail process of power system reliability evaluation considering ESS cooperated WTG is presented using case study of Jeju island power system in the paper.

• Asia pacific journal of information systems
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• 제27권2호
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• pp.99-125
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• 2017

In this study, we propose an operations model to automate a home energy management system (HEMS) that utilizes an energy storage system (ESS) in consideration of consumer utility. Most previous studies focused on the system for the profits obtained from trading charged energy using large-scale ESS. By contrast, the present study focuses on constructing a home-level energy management system that considers consumer's utility over energy consumption. Depending on personal preference, some residential consumers may prefer consuming additional energy to earn increased profits through price arbitrage and vice versa. However, the current system could not yet reflect on this aspect. Thus, we develop an operations model for HEMS that could automatically control energy consumption while considering the level of consumer's preference and the economic benefits of using an ESS. The results of simulations using a dataset of the Korean market show that an operations policy of charging and discharging can be changed depending on consumer's utility. The impact of this policy is not ignorable. Moreover, the technical specifications of ESS, such as self-discharge rate and round-trip efficiency, can affect the operations policy and automation of HEMS.

• 전기학회논문지
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• 제67권11호
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• pp.1401-1407
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• 2018

This paper proposed a method of energy storage system (ESS) operation to increase acceptable production of renewable energy (RE). We analyzed the rebound effect that does not show a demand increase even if the capacity of the ESS is increased and considered the charging time by analyzing the time when the output limit is most generated. The rebound effect was mitigated by adjusting the discharging time of the ESS, and the effect of the increase of acceptable production of the renewable energy was analyzed by adjusting the charging time.

• 전력전자학회논문지
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• 제22권4호
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• pp.330-335
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• 2017

Increased fossil fuel consumption causes global warming, environmental pollution, and abnormal climate change. Wind-generated power installation is proposed to solve this problem. Recently, the wind power plant construction case encourages the installation of the energy storage system (ESS) to improve the intermittency of wind power. The maximized ESS operation profits connected to wind power are not generated in the simplest operation pattern of charging at night and discharging at day. The battery charging efficiency improvement should be considered to get more profits. Thus, there is a possibility of increasing ESS operation profits by analyzing the battery AC and DC charging/discharging efficiency and the yearly average sealed maintenance free (SMP) in hours. In this paper, the battery impedance characteristic, AC and DC charging/discharging efficiency, and the yearly average SMP are analyzed. The operation scenario to improve the ESS battery charging efficiency connected to wind power is proposed and verified via simulation.

• 한국태양에너지학회 논문집
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• 제35권3호
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• pp.57-63
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• 2015

This paper presents a solution by introducing energy storage system(ESS) to solve an annual blackout due to a typhoon or electrical failure in Udo Island. This island is now receiving electrical power through undersea cables from the Jeju Island. During blackout period, ESS will supply the electricity. And it is necessary to estimate the ESS capacity and control the transient state for the operation of stable power system. For the verification of proposed method, ESS capacities have been estimated according to base load and the minimum capacity of only home appliance in Udo Island. Also, in case of restoring from the fault, the algorithm for synchronization is proposed. Finally, the simulation results by using the PSCAD/EMTDC program will show the feasibility.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.637-638
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• 2015

This paper review the technical trends of ESS(Energy Storage System). The ESS has been displaced by cathode, anode, electrolyte, and separator. The lithium-ion battery is getting the most attention in the ESS. In this paper, we especially want to review a look at technology trends of the cathode and the separator for lithium-ion battery.