Search results for: Uchechi Chibuko

Authors: Uchechi Chibuko, Tsvetelina Merdzhanova, Solomon Agbo, Uwe Rau, Ursula Wurstbauer, Oleksandr Astakhov

Abstract:

Coupling of Photovoltaics (PV) to water electrolysers for production of hydrogen via water splitting holds great potential for long term energy storage and transportation. Similarly, the intermittency of PV power on short timescale from hours to days is more efficiently covered by batteries. In this work, we present two different system configurations. The first is the connection of a PV module to an alkaline electroylser/electrochemical (EC) cell stack referred to as a PV-EC system. This is carried out using a direct coupling approach for simplicity, implying the absence of any power electronics for the PV module maximum power point (MPPT) tracking. The second system involves connecting a lithium-titanium-oxide (LTO) battery (B) pack parallel to the electrolyser which is connected to a PV module and referred to as a PV-EC-B system also using a direct coupling approach. The first motivation of studying the two different systems is the possibility of improved stability and round-the-clock operation of the electrolyser in the presence of the battery pack connected to it. In PV-EC configuration the electrolyser remains naturally idle during night times/ periods of insufficient irradiance which can lead to accelerated degradation and safety concerns. For the PV-EC-B configuration, the power of the PV is split between the electrolyser and the battery during the day enabling an extended operation of the electrolyser during the night/periods of insufficient solar irradiance as the battery powers the electrolyser. We delve into two major implications of this effect using optimized experimental procedures with the use of GaAs concentrator PV modules with an efficiency of 34.5% at 17.3 suns. The first implication deals with how the solar-to-hydrogen (STH) efficiency of the systems is affected. The STH efficiency limit of the PV-EC configuration is obtained using an already established theoretical analysis of the electrolyser polarization curve. We therefore show that the experimental result of the PV-EC system yields an STH efficiency of 23.0% which is only 0.5% absolute less than its obtainable STH limit of 23.5%. However, the STH efficiency of the PV-EC-B is obtained to be 25.4% which is not only above the STH efficiency in the PV-EC configuration but also 1.9% absolute above the theoretical STH efficiency limit in the PV-EC configuration. The gain in STH efficiency is synergistic despite battery related losses as the electrolyser in the PV-EC-B configuration converts the same solar power as in the PV-EC system but at lower overpotentials. The second implication is the possibility of the electrolyser downscaling since the battery provides the possibility of running the electrolyser at lower potentials/ peak power. Our results show that the relative electrolyser size can be downscaled by a factor of 2 with the addition of a battery pack while keeping the STH efficiency without batteries. These two orthogonal investigations will be presented in well-defined steps showing determination of power requirements of the electrolyser, PV sizing, PV operation methodology using PV emulation, experimental obtained parameters and analysis of results. The results form a basis for investigation into more realistic operation, upscaling and techno-economic implications.

Keywords: photovoltaic, electrolyser, battery, solar-to-hydrogen efficiency

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Authors: Ozioma Beauty Nwaodu, Adebowale E Salako, Omolara Mabel Akinyemi, Nkechi Uche, Isuama Isu, Uchechi Jane Elechi

Abstract:

Goats form an integral part of livestock production in the tropics. Meat potential is determined subjectively by resource poor livestock keepers, using hand to measure the rump width (RW). Objective evaluation of meat potential in different breads of goats can overcome problems associated with subjective evaluation. Hence, the objectives were to predict meatiness in Red Sokoto (RS), Sahel and the West African Dwarf (WAD) goats, using product of the body length (BL), wither height (WH) and (RW) and to indicate the inherent size of each breed, using WH: BL ratio. These three parameters were used because they are less environmentally sensitive. A total of 2849 goats were sampled purposefully from the Akinyele and Oranyan markets in Ibadan, Oyo State Nigeria. RS showed no significant difference for BL and WH but different from the RW of both sexes (p < 0.01). Similarly WAD showed no significant difference for the BL and WH, but differed (p < 0.01) between sexes for RW. Using the ANOVA, BL:WH ratio showed no significant difference between the breeds. WAD goats have the highest mean for BL:WH ratio. Western meat livestock is primarily identified using BL:WH. The combinations of these body parameters as indicator for meat type in meat animals showed that WAD goat has more potential to lay down meat, than RS and Sahel.

Keywords: quantitative, morphologial traits, descriptive analysis, goats

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Authors: Vivian Uchechi Okpala

Abstract:

Background: Millions of workers die every year as a result of occupational hazards, accidents and injuries, which are as a result of non- compliance to the laws or legislations guiding the health, safety and welfare of workers in the industries. This and many more lead to the assessment of implementation of the health and safety contents of the Nigerian Factories Act (NFA) by small and medium scale industries in Anambra State. Objectives: The study is aimed at achieving the following specific objectives; to assess the extent of implementation of Part-II Health and Part -III Safety (General Provisions), implementation of Part II Health and Part -III Safety (General Provisions Nigerian Factories Acts based on the age of the industries, locations of the industries and level of education of the workers of the small and medium scale industries Methods: the research design that was used for this study was descriptive survey research design, Area of this study was Anambra state, The population for this study comprised 180 chairmen/presidents of union workers of manufacturing industries in Anambra State, The instrument used for this study was structured questionnaire titled ‘assessment of implementation of NFA health and safety contents by small and medium scale industries, results: From the analysis, the following findings were made: Results: The medium scale industries implemented the Part-II Health and Part III Safety (General provisions) better than the small scale industries in Anambra state, the age of the industries, location of the industries and the level of education of the workers in the industries significantly influenced the implementation of the Part III Safety (General Provisions) of NFA, the location of the industries significantly influenced the implementation of the Part II-Health (General Provisions) of NFA. Conclusion: there was generally a certain level of implementation of the factories Act, there is need for more improvement, strict inspection by the regulatory agencies. Implications of the study were highlighted and several suggestions for further studies were made. Based on the findings, several recommendations were made including that the Ministry of Labour and Productivity and the Ministry of Health should strengthen planned information, strict policies to sanction the offenders. Keywords: Occupational Health and Safety, Nigerian Factories Act

Keywords: occupational health and safety, Nigerian factories act, workers, welfare

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Authors: Punit Gandhi, J. C. Brezet, Tim Gorter, Uchechi Obinna

Abstract:

This paper introduces how weather forecasting could help in more efficient energy management for smart homes with the use of Home Energy Management Systems (HEMS). The paper also focuses on educating consumers and helping them make more informed decisions while using the HEMS. A combined approach of technical and user perspective has been selected to develop a novel HEMS-product-service combination in a more comprehensive manner. The current HEMS switches on/off the energy intensive appliances based on the fluctuating electricity tariffs, but with weather forecasting, it is possible to shift the time of use of energy intensive appliances to maximum electricity production from the renewable energy system installed in the house. Also, it is possible to estimate the heating/cooling load of the house for the day ahead demand. Hence, relevant insight is gained in the expected energy production and consumption load for the next day, facilitating better (more efficient, peak shaved, cheaper, etc.) energy management practices for smart homes. In literature, on the user perspective, it has been observed that consumers lose interest in using HEMS after three to four months. Therefore, to further help in better energy management practices, the new system had to be designed in a way that consumers would sustain their interaction with the system on a structural basis. It is hypothesized that, if consumers feel more comfortable with using such system, it would lead to a prolonged usage, including more energy savings and hence financial savings. To test the hypothesis, a survey for the HEMS is conducted, to which 59 valid responses were recorded. Analysis of the survey helped in designing a system which imparts better information about the energy production and consumption to the consumers. It is also found from the survey that, consumers like a variety of options and they do not like a constant reminder of what they should do. Hence, the final system is designed to encourage consumers to make an informed decision about their energy usage with a wide variety of behavioral options available. It is envisaged that the new system will be tested in several pioneering smart energy grid projects in both the Netherlands and India, with a continued ‘design thinking’ approach, combining the technical and user perspective, as the basis for further improvements.

Keywords: weather forecasting, smart grid, renewable energy forecasting, user defined HEMS

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