• Journal of Bio-Environment Control
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• v.5 no.1
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• pp.57-64
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• 1996

To use effectively the solar energy in greenhouse heating, a high performance solar collector should be developed. And then the size of the solar collector and thermal storage tank should be determined through the calculation of heating load. The solar collector must be set in the optimum tilt angle and direction to take daily solar radiation maximally, and the flow rate of heat transfer fluid through the solar collector should be kept in the optimum range. In this research, the performance tests of a capillary tube solar collector were performed to determine the optimum water flow rate and the results summarized as follows. 1. The regressive equations for efficiency estimations of the capillary tube solar collector in the open loop were modeled in the water flow rate of 700-l,000 $\ell$/hr. 2. The optimum water flow rate of the solar collector was estimated by the second order polynomial regression and the maximum efficiency was 80% at the water flow rate of 850 $\ell$/hr. 3. The solar thermal storage system consisted of a capillary tube solar collector and a water storage tank was tested at the water flow rate of 850 $\ell$/hr in the closed loop, and obtained the solar thermal storage efficiency of 55.2%. 4. As the capillary tube solar collector engaged in this experiment was made of non-corrosive polyolefin tubes, its weight was as light as 1/30 of the flat plate solar collector made of copper tubes. Therefore it was considered to be suitable for the greenhouse heating system.

• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.221-228
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• 2014

In this study, we evaluated the efficiency of the dye-sensitized solar cell, through an analysis of the amount of energy and solar radiation according to the season. Solar array was installed next to a greenhouse in Gyeongsang National University (Latitude : N $35^{\circ}$ 9' 9.20", Longitude : E $128^{\circ}$ 5' 44.90", Altitude : 52 m), over a period of four months between August 2012 and February 2013, and solar radiation and generated electrical energy was measured and compared. The values was the greatest in October, showing that the vertical solar radiation on panel area was about 1,013.03MJ and the amount of generated power was about 4.87 kWh. The lowest values were obtained in November, showing that the vertical solar radiation on the panel area was about 755.25MJ and the amount of generated power was about 3.34 kWh. The average efficiency values were 3.12% in August, 2.60% in October, 2.39% in November, and 2.23% in February, respectively. Results of the study would be used as basic data when applying dye-sensitized solar cells to greenhouses in the future.

• Journal of the Korean Professional Engineers Association
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• v.39 no.5 s.188
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• pp.20-24
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• 2006

The energy of 97% consumed by our country depends on it's import from foreign market. This article covers hydrogen, fuel-cell, coal liquefaction gasification energy, and solar, wind, photovoltaic, hydro power, ocean, waste, geothermal, bio energy that is renewable energy, and so on, which are new-generation energy sources, increasing the concern on new & renewable source of enenrgy in future.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.833-844
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• 2008

Bio-energy offers the opportunity to lessen fossil fuel consumption. Energy derived from solar, wind, hydroelectric, geothermal, and biomass sources are considered renewable. Because most forms of bio-energy are derive deither directly or indirectly from the sun, there is an abundant supply of renewable energy available, unlike fossil fuels. The use of bio-energy also provides environmental, economic and political benefits. Bio-energy can be produced from a marine source such as biomass provides a $CO_2$ neutral, non-polluting form of energy. In this paper, the potential of marine biomass is increasingly discussed, given the size of the resource in that more than three quarters of the surface of planet earth is covered by water.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.1-5
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• 2008

Negative environmental consequences of fossil fuels and the concerns about their soaring prices have spurred the search for alternative energy sources. While other alternative energies-like solar, wind, geothermal, hydroelectric, and tidal-offer viable options for electricity generation, around 40% of total energy consumption requires liquid fuels like gasoline or diesel fuel. This is where bio-energy/biofuels is especially attractive, where they can serve as a practical alternative to oil. The production of liquid biofuels for transportation will depend upon a stable supply of large amount of inexpensive cellulosic biomass obtained on a sustainable basis. This paper reviewed development status of transportation bio-energy for vehicles, technical barriers to the production of cellulosic ethanol, and the global future of bio-diesel and ethanol production.

• Journal of Plant Biotechnology
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• v.40 no.4
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• pp.185-191
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• 2013

Over the past decades, carbon dioxide concentration of the atmosphere of the world has increased significantly, and thereby the greenhouse effect has become a social issue. To solve this problem, new renewable energy sources including solar, hydrogen, geothermal, wind and bio-energy are suggested as alternatives. Among these new energy sources, bio-energy crops are widely introduced and under rapid progress. For example, corn and oilseed rape plants are used for the production of bio-ethanol and bio-diesel, respectively. However, grain prices has increased severely because of the use of corn for bio-ethanol production. Therefore, non-edible switchgrass draws attention as an alternative source for bio-ethanol production in USA. This review describes the shortage of fossil energy and an importance of switchgrass as a bio-energy crop. Also, some characteristics of its major cultivars are introduced including growth habit, total output of biomass yields. Furthermore, biotechnological approaches have been conducted to improve the productivity of switchgrass using tissue culture and genetic transformation.

• Journal of the Korean Solar Energy Society
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• v.36 no.1
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• pp.19-26
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• 2016

Biomass has been used for energy sources from the prehistoric age. Biomass are converted into solid, liquid or gaseous fuels and are used for heating, electricity generation or for transportation recently. Solid biofuels such as bio-chips or bio-pellet are used for heating or electricity generation. Liquid biofuels such as biodiesel and bioethanol from sugars or lignocellulosics are well known renewable transportation fuels. biogas produced from organic waste are also used for heating, generation and vehicles. Biomass resources for the production of above mentioned biofuels are classified under following 4 categories, such as forest biomass, agricultural residue biomass, livestock manure and municipal organic wastes. The energy potential of those biomass resources existing in Korea are estimated. The energy potential for dry biomass (forest, agricultural, municipal waste) were estimated from their heating value contained, whereas energy potential of wet biomass (livestock manure, food waste, waste sludge) is calculated from the biological methane potential of them on annual basis. Biomass resources potential of those 4 categories in Korea are estimated to be as follows. Forest biomass 355.602 million TOE, agricultural biomass 4.019 million TOE, livestock manure biomass 1.455 million TOE, and municipal organic waste 1.074 million TOE are available for biofuels production annually.

• Journal of the Korean Solar Energy Society
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• v.31 no.4
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• pp.122-127
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• 2011

A bee venom is very useful and expensive medical resource. A bee venom collector has some difficulties and inconveniences because of its complex component. This is used normal battery as an electric power. However, using the solar cell of the bee venom collector reduces economic burden and guarantees high efficiency. We have performed comparative experiment between the bee venom collector to use battery and the one to use solar cell(polycrystalline silicon) by collecting the bee venom simultaneously. At the same electricity, the electric frequency(AC),312 Hz is more superior than 450Hz. This paper verified through the experiments that the bee venom collector to adopt solar cell is more effective than normal collector.

• New & Renewable Energy
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• v.19 no.1
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• pp.12-21
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• 2023

Governments and global companies are working towards using renewable sources of energy, such as solar, wind, and biomass, to reduce dependency on fossil fuels. In the defense sector, the new strategy seeks to increase the sustainable use of renewable energy sources to improve energy security and reduce military transportation. Renewable energy technologies are affected by factors such as climate, resources, and policy environments. Therefore, governments and global companies need to carefully select the optimal renewable energy sources and deployment strategies. Biomass is a promising energy source owing to its high energy density and ease of collection and harvesting. Many techniques have been developed to convert the biomass into electrical energy. Recently, diverse types of fuel cells have been suggested that can directly convert the chemical energy of biomass into electrical energy. The recently developed biomass flow fuel cell has significantly enhanced the power density several hundred times, reaching to ~100 mW/cm². In this review, we explore various strategies for producing electrical energy from biomass using modern methods, and discuss the challenges and potential prospects of this method.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.10
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• pp.491-496
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• 2014

In general, the entire air supply of a bio-safety laboratory (BSL) should be exhausted on the outside to ensure bio-safety, and the air conditioning system should always be operated to maintain a difference in the room pressure. As a result, the annual energy consumption of such a building is approximately five or ten times higher than that of an office building of the same magnitude. Thus, this study applies an actual operating system that targets BSL. The energy consumption is analyzed using the Energy Plus V8.0 program (an energy analysis program), and five kinds of cases that depend on the energy consumption of the basic BSL system are also analyzed. As a result, the energy consumption in Case 1 (basic system) is of 324.95 GJ. When the basic system of Case 1 is compared to that in Case 2 (basic system+passive design with exterior envelopes), an annual energy savings of is 6.9% is achieved. For Case 3 (basic system+Photovoltaic, PV) 12.7% is achieved, and for Case 4 (Solar Geothermal Hybrid System of renewable energy, SGHS) 49.5% is achieved. If a passive design with exterior envelopes and renewable energy system (PV+SGHS) is combined, as in Case 5, the energy consumption would be 118.15 GJ. Therefore, when this last system is compared to a basic system, the passive design with exterior envelopes and renewable energy system (PV+SGHS) can reduce energy consumption by 63.6%.