• Energy Research
• 7. Clean energy close
• Renewable Energy close

Abstract Compared with other traditional energy sources, renewable energy, which results the less pollution and has numerous resources, is a significant factor in addressing the current issues of the serious environmental pollution and the resource depletion. Large-scale renewable energy integrated to the grid could bring change in both morphological structure and operation modes of energy transmission. Therefore, it is necessary to research the evolution mechanism of the future transmission network with a high proportion of the renewable energy. In this paper, an evolution framework of power system with high proportion of renewable energy is proposed. Firstly, a network equivalence and simplification based on power transfer distribution factors (PTDFs) is proposed, which can effectively simplify the decision-making process of evolution of large-scale power system. Then, an annual production simulation (8760 h) which takes into account renewable energy and load fluctuations is used to find out the bottleneck of the power grid. Based on the above methods, evolution strategy of power system with high proportion of renewable energy is studied for finding out optimal expansion strategy. A real power system of Zhejiang province is used as a test system. Test results demonstrate the feasibility of the proposed evolution framework.

Abstract Sunlight Concentrated and transmission for daylighting via optical fibers is a booming technology of direct utilization of solar energy. It uses optical fibers to introduce sunlight deep into building interior. In this work, a sunlight concentrating and transmitting system via plastic optical fibers was developed and tested. This study addressed the cooling problem of the plastic optical fibers under highly irradiation. Polymethylmethacrylate (PMMA) plastic fibers have a strong absorption effect on infrared light, which means that plastic fibers heat up so much when they transmit focused sunlight that they burn. In this study, a comprehensive cooling approach was developed to solve the overheating problem of plastic optical fibers, which consists of an infrared filter, cooling water and a homogenizer. The transmission efficiency of the system was measured to be about 15%. Experiments show that the comprehensive cooling measures developed can ensure that PMMA plastic optical fibers are in a safe temperature range. This shows that it is feasible to use low-cost plastic optical fibers instead of expensive silica fiber to transmit high flux for daylighting.

Abstract Bamboo has been considered a potential feedstock of energy for the future. It can be subjected to the pyrolysis for biofuels production. The thermogravimetric analysis (TGA) combined with differential thermogravimetric analysis (DTG) for bamboo was carried out prior to pyrolysis. The thermal degradation of bamboo was mainly between 230 and 420 °C. The conventional pyrolysis of bamboo was investigated in a bubbling fluidized-bed reactor using silica sand. The product distribution and composition of pyrolysis bio-oil were dependent on biomass component and operating conditions such as pyrolysis temperature, fluidization velocity, and particle size of biomass. The fractional catalytic pyrolysis of bamboo was also studied to upgrade the pyrolysis vapor, using HZSM-5 and red mud. The highest yield of bio-oil was 54.03 wt% compared to 49.14 wt% and 50.34 wt% of HZSM-5 and red mud catalyst, respectively. In the red mud catalytic pyrolysis, the oxygen content was rejected from pyrolysis vapor mostly via decarboxylation to produce more CO2 than CO; in contrast, for the HZSM-5 catalytic pyrolysis, the production of CO through decarbonylation was more favored than CO2. The main composition of catalytic pyrolysis bio-oil was 4-vinylphenol, which was employed as a raw material source to synthesize valuable material for energy storage.

Abstract In some shelf sea regions of the world, the tidal range is sufficient to convert the potential energy of the tides into electricity via tidal range power plants. As an island continent, Australia is one such region – a previous study estimated that Australia hosts up to 30% of the world’s resource. Here, we make use of a gridded tidal dataset (TPXO9) to characterize the tidal range resource of Australia. We examine the theoretical resource, and we also investigate the technical resource through 0D modelling with tidal range power plant operation. We find that the tidal range resource of Australia is 2004 TWh/yr, or about 22% of the global resource. This exceeds Australia’s total energy consumption for 2018/2019 (1721 TWh/yr), suggesting tidal range energy has the potential to make a substantial contribution to Australia’s electricity generation (265 TWh/yr in 2018/2019). Due to local resonance, the resource is concentrated in the sparsely populated Kimberley region of Western Australia. However, the tidal range resource in this region presents a renewable energy export opportunity, connecting to markets in southeast Asia. Combining the electricity from two complementary sites, with some degree of optimization tidal range schemes in this region can produce electricity for 45% of the year.

Abstract Sugarcane is a major crop cultivated globally and the residue left over after the crop harvest and extraction of juice is a good biomass source that can be used for the production of several useful chemicals. The sugarcane bagasse is an excellent substrate for the production of various biochemicals and enzymes through fermentation. Now major interest is focused on the utilization of these residue for biofuel production. The sugarcane crop residue is rich in cellulose and hemicellulose, hence it can be used for the production of bioethanol and other liquid transportation fuels. The present review gives a detailed account of the availability of sugarcane residue and various commercially important products that can be produced from this residue. It also provides recent developments in R&D on the bioconversion of sugarcane crop residue for value added products.

Abstract To address the problem of fossil fuel usage at the Missouri University of Science and Technology campus, using of alternative fuels and renewable energy sources can lower energy consumption and hydrogen use. Biogas, produced by anaerobic digestion of wastewater, organic waste, agricultural waste, industrial waste, and animal by-products is a potential source of renewable energy. In this work, we have discussed Hydrogen production and End-Uses from CHHP system for the campus using local resources. Following the resource assessment study, the team selects FuelCell Energy DFC1500™ unit as a molten carbonate fuel cell to study of combined heat, hydrogen and power (CHHP) system based on a molten carbonate fuel cell fed by biogas produced by anaerobic digestion. The CHHP system provides approximately 650 kg/day. The total hydrogen usage 123 kg/day on the university campus including personal transportation applications, backup power applications, portable power applications, and other mobility applications are 56, 16, 29, 17, and 5 respectively. The excess hydrogen could be sold to a gas retailer. In conclusion, the CHHP system will be able to reduce fossil fuel usage, greenhouse gas emissions and hydrogen generated is used to power different applications on the university campus.

Abstract A vapour absorption refrigeration system (VARS) in which a transfer tank replaces the conventional solution pump is analysed. Six fluid pairs with R22 as the refrigerant and different absorbents: DMA; DMF; DMETEG; DMETrEG; DMEDEG; and NMP are considered. Variations in COP, circulation ratio, percent mass of generated vapour utilised for transfer-tank operation, and minimum generator temperature are compared over a wide range of operating conditions. In general, R22-DMA, R22-DMF, and R22-DMETrEG are preferable for a transfer-tank operated VARS. At high generator temperatures or low condenser temperatures, R22-DMA gives the best overall performance. When the temperatures of the evaporator, absorber, and condenser are high, one may prefer R22-DMF as the working fluid.

Abstract The paper aims to discuss the speedy spread of the use of optical fibres or optical light films lighting systems, as an alternative to classical lighting systems in buildings. A series of architectural projects has been selected to provide more evidence about advantages of these new lighting equipement, in terms of thermal and lighting comfort together with low cost energy. As a matter of fact their efficiency has even lead some professionals to use them in some buildings after suppression of the initial lighting system. The fact that the optional fibres or optical light films are used in various spaces has enabled to hope for a development of their applications in interiors and especially public places, in hot contries where heat output from traditional lighting bulbs is more likely to provide discomfort and hence where requirement for air conditionning is unavoidably maximised.

We tested this system with objectives to plan and apply this system in Japan, and examined its cooling effectiveness and ir flow generation