Journal of Energy Research and Reviews

Bananas are the main source of stable food among the Kisii people in Kenya. Apart from the banana fruit, the other parts are usually thrown to waste although can be used in a useful manner like to generate biogas. This research sought to investigate biogas production potential from different parts of a banana plant in Kisii County, Kenya. In the study, 2 kg of banana leaves, pseudo-stem, fruit bunch stalk (FBS) and peels were collected as feed-stocks for a laboratory-scale anaerobic digester to produce biogas. The experiment was carried out in a multi-stage anaerobic digestion system operated under mesophilic temperature (30-35°C). Various process parameters were measured including total solid, volatile solid and volume of biogas produced. After completion of 21-day digestion at an average temperature of 33°C, specific Biogas yields reached were about 16.5 litres/kg (leaves), 13.5 litres/kg (pseudo-stem), 12.7 litres/kg (fruit bunch stalk) and 15.1 litres/kg (peels). The optimum daily production of biogas was between the 13^th-15^th day. Cumulatively, it was observed that after the 15^th day, almost all of the biogas had been released from the digester. By doing a simple computation based on energy calculation, it was found that 61% of the energy expected from a similar quantity by other researchers. The study showed that banana leaves have highest potential for biogas as compared to the other parts.

This study assess the nexus between climate change and media coverage vis a vis the influence of the diversified positions on climate change and how it pave way for the creation of new perspectives and understanding amongst individuals about climate change issue in Kano, Nigeria. The study concludes that there is a very high level of media awareness about climate change issue in Kano; media coverage and representations about climate change has positively impacted and shaped individuals’ understanding about climate change issue. The study also reveal that social media platform remain the predominant source of information about climate change issue in Kano; and the causes of climate change in Kano is deemed to be artificial rather than natural; while change in weather pattern is the noticeable consequences of climate change in Kano. The study concludes that media coverage and representations about climate change shapes the perspectives, understandings and knowledge of individuals about climate change in Kano, Nigeria.

Aims: To estimate the optimum tilt angle and maximum solar power for different geoclimatic zones in Nigeria.

Methodology: In this study, the surface data of direct and diffuse solar radiations spanning 2013 to 2017 were obtained from the archives of the Modern-Era Retrospective Analysis for Research and Application for 20 stations spread across Nigeria. To study the direct relationship between the solar power on a photovoltaic panel and the solar radiation, the values of the direct, diffuse, and ground-reflected components of solar radiation were calculated for six tilt angles ranging from 15° to 90° using anisotropic models. Afterwards, the maximum values of the solar power and the corresponding tilt angles, as well as the average number of solar panels that can be used to cater for the electricity needs of households in all the geoclimatic zones, were estimated.

Results: Analyses showed that the maximum solar power was received at tilt angles of 30° and 45° from October till February, and tilt angles of 15° and 30° from March till September in all the study locations. For instance, the Sahel and Guinea Savanna zones had the highest solar power, whereas Derived Savanna and Coastal zones had relatively low power. Based on the results, it was determined that the number of solar panels required in the sahel zone would be lower than those of the other zones.

Conclusion: It can be inferred from the results that the reception of maximum solar power is at the tilt angle of 45^o in Sahel, Guinea, and Derived Savanah regions, and at 30^o in the Coastal region. The results of this research will provide solar engineers with accurate information on the orientation and tilt of PV modules for efficient power generation.

The main objectives of this study were to determine and analyze energy use efficiency in sugar beet production, and to make cost-benefit analysis in Guneid area - Sudan. An experiment was carried out using three tillage implements (disc plough, disc harrow and ridger) for land preparation, seven days irrigation interval and mechanical planter. The treatments were replicated four times in a completely randomized block design. The results showed that total energy consumption in sugar beet production was 35099.20MJha^-1, out of which 52.33% of fertilizer energy, 18.0% water energy and 9.0% of diesel energy. The energy use ratio was 28.71 and energy productivity was 1.71kgMJha^-1. The results also showed that 73.6% of total energy input was in non-renewable energy form, and only 26.4% was in renewable form, while 34.1% was in from of direct energy and 65.9% indirect energy. Cost-Benefit analyses showed that the total return, net return, benefit–cost ratio and productivity of crop were 2689.6 US$ha^-1, 990.8 US$ha^-1, 1.58. and 35.3kgUSD^-1 respectively. Although large amounts of energy consumption for sugar beet production increased the yield, it also caused in problems related to environmental pollution, land degradation, nutrient loading and pesticide toxicity. Therefore, it is important to look for methods and systems that can reduce the negative effect of high energy inputs and to develop more efficient, economical and environmentally friendly agricultural production systems that increase energy use efficiency and crop yield.

Increased energy consumption coupled with the ongoing climate change are urging us to develop more sustainable energy alternatives, including biofuels produced from renewable biomass. Our heavy reliance on fossil-derived fuels has not only gained intense public attention in recent years, but has also prompted us to intensively study the production of sustainable biofuels from renewable energy sources via microbial fermentation.  Owing to the recent advances and availability of state-of-the-art molecular tools, our knowledge about anaerobic microorganisms and their direct and indirect contributions in the production of different biofuels have increased tremendously. Anaerobic microorganisms are mainly utilized for commercial production of biofuels such as; biogas and fuel alcohols from renewable organic matter, while photosynthetic microorganisms convert inorganic carbon and water to potential fuels (e.g. fuel alcohols) and fuel precursors (e.g. biomass, starch, lipids). Although metabolically engineered microorganisms, programmed to redirect renewable carbon sources into desired fuel products, are contemplated as best choices to obtain high volumetric productivity and yield, however, native populations of anaerobic microorganisms are still considered the primary choice for the production of biogas and bioethanol. These anaerobic microorganisms responsible for different degradation pathways and their functions in anaerobic digesters are continuously being updated.  In this review, we discuss the essential role of anaerobic microbes in biogas and bioethanol production via consolidated anaerobic process. Additionally, key enzymatic reactions and microbiota involved in the degradation steps and in the production pathways are specifically highlighted. We also discussed the challenges that still exist for biofuel production from native populations of anaerobic microorganisms and their possible solutions.