• Journal of Information Processing Systems
• /
• 제11권1호
• /
• pp.116-124
• /
• 2015

Smart grids propose new solutions for electricity consumers as a means to help them use energy in an efficient way. In this paper, we consider the demand-side management issue that exists for a group of consumers (houses) that are equipped with renewable energy (wind turbines) and storage units (battery), and we try to find the optimal scheduling for their home appliances, in order to reduce their electricity bills. Our simulation results prove the effectiveness of our approach, as they show a significant reduction in electricity costs when using renewable energy and battery storage.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2006년도 추계 학술발표회
• /
• pp.169-178
• /
• 2006

The pumped-storage power system is the one of the hydroelectric power systems, generating electricity with hydraulic head difference. In this system, the electricity is produced during the hours of peak demand by using water that has been pumped into an upper reservoir from a lower reservoir during the hours of low demand. Generally, the system consists of an under-ground power house and tunnels such as the headrace, pressure, and tailrace tunnels. The Chungsong pumped-storage power station is the sixth one In the pumped-storage power station in Korea. Both the regional self-government and the population of chungsong -Goon had made a great effort to draw this power station construction into this area. The proposed Chungsong pumped-power station construction project was accepted by the central government as a part of the national electricity plan for the first time in Korea.

• International Journal of Computer Science & Network Security
• /
• 제24권6호
• /
• pp.77-82
• /
• 2024

The Smart home energy consumption represents much of the total energy consumed in advanced countries. For this reason, the main objectif of this paper is to study the energy consumption profile by day for each home appliances: controllable appliances for example Washing machine, Tumble dryer and Air conditioning and uncontrollable appliances for example TV, PC, Lighting, Refrigerator and Electric heater. In this paper, we start with presentation of a smart home energy management systems. Next, we present the modeling and simulation of controllable appliances and uncontrollable appliances. Finally, concludes this paper with some prospects. The modeling and the simulation of a Smart home appliances is based on MATLAB/Simulink software.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제12권4호
• /
• pp.1553-1571
• /
• 2018

Currently, many of schemes for smart grid data aggregation are based on a one-level gateway (GW) topology. Since the data aggregation granularity in this topology is too single, the control center (CC) is unable to obtain more fine-grained data aggregation results for better monitoring smart grid. To improve this issue, Shen et al. propose an efficient privacy-preserving cube-data aggregation scheme in which the system model consists of two-level GW. However, a risk exists in their scheme that attacker could forge the signature by using leaked signing keys. In this paper, we propose a secure and fine-grained electricity consumption aggregation scheme for smart grid, which employs the homomorphic encryption to implement privacy-preserving aggregation of users' electricity consumption in the two-level GW smart grid. In our scheme, CC can achieve a flexible electricity regulation by obtaining data aggregation results of various granularities. In addition, our scheme uses the forward-secure signature with backward-secure detection (FSBD) technique to ensure the forward-backward secrecy of the signing keys. Security analysis and experimental results demonstrate that the proposed scheme can achieve forward-backward security of user's electricity consumption signature. Compared with related schemes, our scheme is more secure and efficient.

• 한국수소및신에너지학회논문집
• /
• 제28권2호
• /
• pp.156-165
• /
• 2017

This study quantitatively assessed the environmental impacts of fuel cell (FC) systems by performing life cycle assessment (LCA) and analyzed their energy efficiencies based on energy return on investment (EROI) and electrical energy stored on investment (ESOI). Molten carbonate fuel cell (MCFC) system and polymer electrolyte membrane fuel cell (PEMFC) system were selected as the fuel cell systems. Five different paths to produce hydrogen ($H_2$) as fuel such as natural gas steam reforming (NGSR), centralized naptha SR (NSR(C)), NSR station (NSR(S)), liquified petroleum gas SR (LPGSR), water electrolysis (WE) were each applied to the FCs. The environmental impacts and the energy efficiencies of the FCs were compared with rechargeable batteries such as $LiFePO_4$ (LFP) and Nickel-metal hydride (Ni-MH). The LCA results show that MCFC_NSR(C) and PEMFC_NSR(C) have the lowest global warming potential (GWP) with 6.23E-02 kg $CO_2$ eq./MJ electricity and 6.84E-02 kg $CO_2$ eq./MJ electricity, respectively. For the impact category of abiotic resource depletion potential (ADP), MCFC_NGSR(S) and PEMFC_NGSR(S) show the lowest impacts of 7.42E-01 g Sb eq./MJ electricity and 7.19E-01 g Sb eq./MJ electricity, respectively. And, the energy efficiencies of the FCs are higher than those of the rechargeable batteries except for the case of hydrogen produced by WE.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• 제4B권2호
• /
• pp.86-91
• /
• 2004

PV power generation, which directly converts solar radiation into electricity, contains numerous significant advantages. It is inexhaustible and pollution-free, silent, contains no rotating parts, and has size-independent electricity conversion efficiency. The positive environmental effect of photovoltaics is that it replaces the more polluting methods of electricity generation or that it provides electricity where none was available before. This paper highlights a novel simple method to abstract the entire parameters of the solar cell. In development, design and operation of PV power generation systems, a technique for constructing V-I curves under different levels of solar irradiance and cell temperature conditions using basic characteristic values of the PV module is required. Everyone who has performed manual acquisition and analysis of solar cell I versus V data would agree that the job is tedious and time-consuming. A better alternative is to use an automated curve tracer to print out the I versus V curves and compute the four major parameters; $V_{oc}$, $I_{sc}$, FF, and . Generally, the V-I curve tracer indicates only the commonly used solar cell parameters. However, with the conventional V-I curve tracer it is almost impossible to abstract the more detailed parameters of the solar cell; A, $R_{s}$ and $R_{sh}$ , which satisfies the user, who aims at the analysis of the development of the PV power generation system, that being advanced simulation. In this paper, the proposed method provides us with satisfactory results to enable us to abstract the detailed parameters of the solar cell; A, $R_s$ and $R_{sh}$.>.

• 신재생에너지
• /
• 제4권2호
• /
• pp.45-51
• /
• 2008

The fuel cell system is environment-friendly and energy efficient system. Especially, the fuel cell cogeneration systems providing heat and electricity to buildings have been developed and applied to a lot of sites in the world to cope with the global warming and $CO_2$ emission problem. This paper presents the result of study on the economic evaluation with super-micro fuel cell (SMFC) cogeneration system by varying the floor area ($132m^2{\sim}331m^2$) of the house, whose system capacity ranges from 0.10 kWe to 0.50 kWe. The electricity demand, heat demand, saved energy cost, and the simple pay-back period have been simulated for the various capacities of fuel cell cogeneration system. As a result, this study suggests the fuel cell system’s capacity decision strategy for a given house area. Contrary to conventional design assumptions, the smaller capacity fuel cell cogeneration system is appropriate for the house of large floor area to defense the progressive electricity tax, and the larger capacity fuel cell cogeneration system is appropriate for the house of small floor area to sell the electricity.

• 한국유체기계학회 논문집
• /
• 제19권6호
• /
• pp.26-33
• /
• 2016

Combined heat and power (CHP) system is one of the power generation system which can generate both electricity and heat. Generally, mid-size and big-size CHP plant in Korea generate electricity from gas turbine and steam turbine, then supply heat from exhaust gas. Actually, CHP can supply heat using district heater which is located at low pressure turbine exit or inlet. When the district heater locates after low pressure turbine, which called back pressure type turbine, there need neither condenser nor mode change operating control logic. When the district heater locates in front of low pressure turbine or uses low pressure turbine extraction steam flow, which calls condensing type turbine, which kind of turbine requires condenser. In this case, mode change operation methods are used for generating maximum electricity or maximum heat according to demanding the seasonal electricity and heat.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
• /
• pp.25-28
• /
• 2008

The fuel cell system is environment-friendly and energy efficient system. Especially, the fuel cell cogeneration systems providing heat and electricity to buildings have been developed and applied to a lot of sites in the world to cope with the global warming and $CO_2$ emission problem. This paper presents the result of study on the economic evaluation with super-micro fuel cell (SMFC) cogeneration system by varying the floor area ($132m^2{\sim}331m^2$) of the house, whose system capacity ranges from 0.10 kWe to 0.50 kWe. The electricity demand, heat demand, saved energy cost, and the simple pay-back period have been simulated for the various capacities of fuel cell cogeneration system. As a result, this study suggests the fuel cell system's capacity decision strategy for a given house area. Contrary to conventional design assumptions, the smaller capacity fuel cell cogeneration system is appropriate for the house of large floor area to defense the progressive electricity tax, and the larger capacity fuel cell cogeneration system is appropriate for the house of small floor area to sell the electricity.

• Advances in Energy Research
• /
• 제5권2호
• /
• pp.129-145
• /
• 2017

In this study, the use of a micro gas turbine system using biogas to supply heating, cooling and electricity loads of a rural building located in rural area around Tehran has been studied. Initially, the amount of energy needed by the farmhouse was calculated and then the number of needed microturbines was determined. Accordingly, the amount of substances entering biogas digester as well as tank volume were determined. The results of this study showed that village house loads including electrical, heating and cooling and hot water loads can be supplied by using a microturbine with a nominal power of 30 kW and $33.5m^3/day$ of biogas. Digester tank and reservoir tank volumes are $67m^3$ and $31.2m^3$, respectively. The cost of electricity produced by this system is 0.446 US$/kWh. For rural area in Iran, this system is not compatible with micro gas turbine and IC engine system use urban natural gas due to low price of natural gas in Iran, but it can be compatible by wind turbine, photovoltaic and hybrid system (wind turbine& photovoltaic) systems.