-
Post-COVID-19 Sustainable Waste-to-Energy Solutions for Uganda’s Displacement Camps: A Review
Reuben Gad Mugagga,
Hope Baxter Chamdimba
Issue:
Volume 10, Issue 2, June 2021
Pages:
32-39
Received:
31 March 2021
Accepted:
19 April 2021
Published:
29 April 2021
Abstract: The launching of the Sustainable Development Goals in 2015 has continually advanced the sustainability paradigm across all corners of the globe. While this has led to the fruition of inherent country policies and plans for Uganda, the country is still trailing below the desired rate of attaining SDGs by 2030. The commencement of this decade of action and the proliferating intensity of the current unprecedented health crisis have thus called for heightened emphasis on inclusive sustainable development for the most disproportionately disadvantaged populations of which refugees form part. The pandemic has forced key stakeholders to shift their focus by re-allocating their scarce resources from disadvantaged communities such as refugee camps, thereby exposing them to severe and unacceptable vulnerability. Coupled to this COVID-19 pandemic is the prevalent energy crisis in displacement camps which shall have far-reaching disruptions. Increased energy access in refugee settlements shall help advance the modest progress made so far. This paper therefore highlights the most promising Waste-to-Energy (WtE) options for displacement camps in the Ugandan context which are evaluated based on a Multi Criteria Decision Analysis (MCDA) matrix upon which deductions of anaerobic digestion and briquettes respectively serve as the best ranked options respectively for more inclusive social economic development in these settings.
Abstract: The launching of the Sustainable Development Goals in 2015 has continually advanced the sustainability paradigm across all corners of the globe. While this has led to the fruition of inherent country policies and plans for Uganda, the country is still trailing below the desired rate of attaining SDGs by 2030. The commencement of this decade of acti...
Show More
-
Application of Artificial Neural Networks for Maximal Power Point Tracking
Amadou Fousseyni Toure,
Fadaba Danioko,
Badie Diourte
Issue:
Volume 10, Issue 2, June 2021
Pages:
40-46
Received:
6 April 2021
Accepted:
26 April 2021
Published:
8 May 2021
Abstract: In this paper, a hybrid controller of maximum power point tracking of photovoltaic systems based on the artificial neuron network has been proposed and studied. The data needed for model generation are obtained from the series of measurements. The training of neural networks requires two modes: the off-line mode to get optimal structure, activation function and learning algorithm of neural networks and in an online way these optimal neural networks are used in the PV system. The hybrid model is made up of two neural networks; the first network has two inputs and two outputs; the solar irradiation and the ambient temperature are the inputs; the outputs are the references voltage and current at the maximal power point. The second network has two inputs and one output; the inputs use the outputs of the first network, and the output will be the periodic cycle which controls the DC/DC converter. The performance of the method is analyzed under the different conditions of climatic variation using the MATLAB/Simulink simulation tool. A we compared our proposed method to the perturbation and observation approach, in terms of tracking accuracy, steady state ripple and response time.
Abstract: In this paper, a hybrid controller of maximum power point tracking of photovoltaic systems based on the artificial neuron network has been proposed and studied. The data needed for model generation are obtained from the series of measurements. The training of neural networks requires two modes: the off-line mode to get optimal structure, activation...
Show More
-
Analysis of Shading Effects in Solar PV System
Dushengere Bernadette,
Maurice Twizerimana,
Alexis Bakundukize,
Bizabakoraho Jean Pierre,
Nsekambabaye Theoneste
Issue:
Volume 10, Issue 2, June 2021
Pages:
47-62
Received:
10 April 2021
Accepted:
26 April 2021
Published:
8 May 2021
Abstract: Due to its advantages, the use of clean energy in general and especially solar PV systems offer a great solution to problems that people face in their everyday life. Generation of energy using solar PV system technology is cheaper and clean technology compared to one of the fossil fuels. Aside from its advantages, this technology still has some drawbacks that affect its performance where the ones caused by shadows are considered as one of the big problems. This research work showed laboratory experiments and simulations to see how the system is affected by shading where a 1.5 kWp PV system has been used for the study. The system has been simulated with PVsyst (7.0.6 version) and experimented within the University of Rwanda/ African Center of Excellence in Energy Studies for Sustainable Development (UR/ACE-ESD) High E-Tech Smart Grid Laboratory. Laboratory experiments showed that whatever shade is applied to the system, the DC voltage and current change (increases or decrease) and DC power decreases. In the simulation, it has been notified that the irradiance losses are dependent on the time of a day, sun position, and the rate of created shadow. From the simulated results, annual energy produced and near shading losses in the non-shaded system is 2373 kWh and 0% respectively while in the shaded system, the annual energy produced was 2055 kWh and 2.1% of near shading losses. This undoubtedly disturbs the performance of the power system as well as other related works. Based on the result for this work, shadow affects the performance of PV systems and the rate at which the PV system is affected depends on the shaded area, position, and how much radiation reaches that shaded area. This increases the system’s instability as it can lose its ability to generate power at the maximum due to the user control algorithm as well as degradation of the output that a PV panel can produce. Furthermore, investigations need to be carried out to modify this work. Providers of energy based on solar systems should sensitize shading issues towards their beneficiaries, and make a follow-up to installed systems so that users can give special attention to shading issues while they operate their system. It is recommended to continue this research within Rwandan Solar power plants considered as a case study for more investigation.
Abstract: Due to its advantages, the use of clean energy in general and especially solar PV systems offer a great solution to problems that people face in their everyday life. Generation of energy using solar PV system technology is cheaper and clean technology compared to one of the fossil fuels. Aside from its advantages, this technology still has some dra...
Show More
-
A Quantitative Study of the Influence of Urban Form on Large-Scale Application of Rooftop Photovoltaics Using Simplified Method
Yutong Li,
Kang Jing,
Fengrong Liu,
Fuyou Zhao
Issue:
Volume 10, Issue 2, June 2021
Pages:
63-75
Received:
29 May 2021
Accepted:
8 June 2021
Published:
16 June 2021
Abstract: The large-scale application of distributed photovoltaic system is often impeded by the shading effect between buildings and mismatch between the solar power generation and building energy consumption. This paper explores the relationship between urban form and rooftop photovoltaic installation and utilization potential with implications for low-carbon city planning. This study first investigated the influence of the urban form on the installation potential of the solar rooftop photovoltaics for 12 cities across China which covering different solar climate zones. The significant impact of the urban density on the photovoltaic installation potential is only observed in the cities in high latitude areas with medium solar radiation, and the negative impact can be mitigated by reducing the building height differences, which up to 25% improvement can be expected. Then, taking Shenzhen as an example, the influence of the urban form on the photovoltaic power generation utilization was further investigated for residential, commercial and office type of district building energy consumption profiles. It is found that the densely developed urban built-up environment has positive effect on the solar power utilization in which high percentage of the self-consumption ratio is observed. The self-consumption ratio of the residential district which is the lowest can be effectively improved by mixing with office and business buildings. For typical urban form in Shenzhen which the BCR and FAR are 0.35 and 2.5 respectively, if carefully planned, the rooftop photovoltaics can provide 12.6~18.5% of the building energy consumption and 69.8~75% of the solar power can be directly used by the building, which make the rooftop photovoltaics an important clean and economical energy resource for low-carbon city development.
Abstract: The large-scale application of distributed photovoltaic system is often impeded by the shading effect between buildings and mismatch between the solar power generation and building energy consumption. This paper explores the relationship between urban form and rooftop photovoltaic installation and utilization potential with implications for low-car...
Show More
-
Assessment of Embodied Energy and Carbon IV Oxide Emission of Concrete Containing Corncob Ash
Aliyu Abubakar,
Abbagana Mohammed,
Duna Samson
Issue:
Volume 10, Issue 2, June 2021
Pages:
76-84
Received:
10 June 2021
Accepted:
21 June 2021
Published:
26 June 2021
Abstract: The purpose of this study is to assess the Embodied Energy (EE) and Carbon IV Oxide (CO2) emissions saving potentials of Corn Cob Ash (CCA) as partial replacement of Ordinary Portland Cement (OPC) in concrete. Cement manufacture is energy intensive and contributes considerable amount of CO2 emissions into the atmosphere. Globally, Concrete is the most consumed man-made material and about 95% of CO2 emissions from a cubic meter of concrete are from cement manufacturing. In this study, the experimental plan was designed to carry out compressive strength, flexural strength, density and water absorption tests on the concrete using 0, 5, 10, 15 and 20% CCA contents to replace OPC. Inventory method of analysis was used to determine the EE and CO2 emission for all the concrete mixes. The results indicated that the water absorption, density, compressive and flexural strength decreased with increase in CCA content and increased with curing period. The optimum blend was obtained at 10% CCA and 90% OPC contents. The EE and CO2 emission decreased with increase in CCA contents. At 20% CCA content the EE was 2382 MJ/m3 which is 12.04% less than that of control samples. Also, 16.37% embodied CO2 emission saving was obtained for samples containing 20% CCA. The regression equations generated gave standard deviation, S, < 1.0, P-value < 0.05, T-statistics > T24, 0.05 and F-statistics > F1, 23, 0.05. All these indicated that there is good relationship between the predictors and the responses.
Abstract: The purpose of this study is to assess the Embodied Energy (EE) and Carbon IV Oxide (CO2) emissions saving potentials of Corn Cob Ash (CCA) as partial replacement of Ordinary Portland Cement (OPC) in concrete. Cement manufacture is energy intensive and contributes considerable amount of CO2 emissions into the atmosphere. Globally, Concrete is the m...
Show More
