scholarly journals Development of A Flat Plate Solar Store

2020 ◽  
pp. 60-85
Author(s):  
Oluwasegun M. Ayoola ◽  
Olawale J. Abidakun ◽  
Taofeeq O. Olajire ◽  
Oluwatimilehin E. Oluwajire ◽  
Adekoya Oluwaseun Abiodun
Keyword(s):  
Fossil Fuels ◽  
Daily Precipitation ◽  
Sweet Pepper ◽  
The Sun ◽  
Average Temperature ◽  
Food Items ◽  
The Past ◽  
Solar Dryer ◽  
Performance Results ◽  
Drying Chamber

<p>The most noteworthy advantage of solar power as compared to other forms of energy is that it is clean and might be supplied with no contamination to the environment. Over the past centuries, it is believed that energy from fossil fuels is less expensive and more helpful than energy from other sources. This research thus results to the successful fabrication of a solar dryer with tests distributed for various performance comparisons like No-load and load performance of the dryer. Direct sun-drying comparisons depicted discernable contrasts within the final moisture content specified. The utmost temperature recorded within the drying chamber and solar dish for No-load are 44.5  and 52  respectively. Whereas when the cupboard is loaded, the highest temperature of 34.5  and least temperature of 23   are recorded. An average temperature of 27  was obtained, thereby giving the solar dryer an exegetic efficiency between 70% and 80%. Performances of the tests were done from 9am to 5pm. The solar store that was designed to heat to the drying chamber within the night was found to possess its most elevated temperature at 43 . These performance results were achievable due to daily precipitation, and in some cases, cloudy days when the sun was not shining at its peak. The load outcome was done with red-sweet pepper and yam food items.</p>

Introduction

2017 ◽  
Author(s):  
Anthony McMichael
Keyword(s):  
Carbon Dioxide ◽  
Fossil Fuels ◽  
Carbon Dioxide Concentration ◽  
First Century ◽  
Ice Age ◽  
Average Temperature ◽  
The Past ◽  
Twenty First Century ◽  
The Difference ◽  
Eighteenth And Nineteenth Centuries

Trends In Global Greenhouse emissions during the first two de­cades of this twenty- first century are leading us to a much hotter world by 2100, perhaps 3°C– 4°C above the late- twentieth- century average temperature and hotter than at any time in the last 20– 30 million years. Further, the rate of heating would be about 30 times faster than when Earth emerged from the most recent ice age, between 17,000 and 12,000 years ago. At that speed, environ­mental changes may outstrip the capacity of many species to evolve and adapt. Having once relied on fires in caves, humans in the late eighteenth and nineteenth centuries increasingly began to burn fossil fuels to release vastly more energy— and, inadvertently, vastly more carbon dioxide. About 600 billion metric tons of that invisible, stable, and odorless gas have been emitted since 1750, about two- thirds of which will persist in the atmosphere for centuries. The resulting 40 percent increase in atmospheric carbon dioxide concentration is the main cause of human- driven climate change. We have wrapped another heat- retaining blanket around the planet, causing warming of Earth’s surface at a rate that far outpaces nature’s rhythms. Humans have lived in climatically congenial times for the past 11,000 years of the Holocene geological epoch compared with the rigors of the preceding ice age. Figure 1.1 shows the world’s estimated aver­age surface temperature over that era, and the right- hand side of the graph shows the likely global warming by 2100 averaged across many published modeled projections. The difference between the peak tem­perature of 7,000 years ago and the nadir of the Little Ice Age 350 years ago is 0.7°C. By early in this twenty- first century, the global average temperature had edged higher than for the past 11,000 years— by 0.6°C in six decades. If the world’s temperature were to rise by 3°C– 4°C within just three generations, our descendants might struggle to remain healthy, raise families, and survive within stable societies. I am certainly not the first to say this … A 4°C temperature increase probably means a global carrying capacity below 1 billion people.

Analysis of Fish Fillet Drying Rates under Three Solar Energy Drying Systems

2009 ◽  
Vol 62-64 ◽  
pp. 518-524
Author(s):  
Gikuru Mwithiga ◽  
Samuel Gathuki Mwangi
Keyword(s):  
Ambient Air ◽  
Absolute Maximum ◽  
Airflow Rate ◽  
Fish Fillet ◽  
Sun Drying ◽  
Average Temperature ◽  
Green House ◽  
Maximum Value ◽  
Solar Dryer ◽  
Drying Chamber

A small Box type solar dryer with controllable air inlet was designed and tested. The dryer had a mild steel absorber plate and a polyvinyl chloride (pvc) transparent cover and could be adjusted to allow variation in airflow rate through the drying chamber. A convectional green house covered with transparent pvc and into which a drying tray stand at a height of 90 cm above the ground was placed made up the second drying method. The rate of air flow through the green house could be controlled by adjusting the opening at either end of the tunnel. The third method of drying which also served as the control is sun drying in which case the drying trays was placed 90 cm above the ground but left unenclosed to allow free flow of ambient air. The air temperature at points just above the drying rack was monitored for all three drying systems under no load conditions from morning to late afternoon. The temperature was also monitored during drying when the trays were loaded with fish of different fillet thicknesses. The rate of loss of moisture was also monitored by weighing the fillets at regular interval until the moisture dropped to 20%, dry basis or lower. The average temperature inside the plenum chamber of the box type solar dryer was found to have a high daily value of 71.1OC although an absolute maximum value of 74.4OC was recorded. This maximum value could be reached on cloudless days between the hours of 13:00 and 1400. The green house recorded a slightly lower average temperature and its peak value occurred latter in the day. Both the green house and the box-type solar dryer had average drying chamber temperatures that were more than 30 centigrade degrees above ambient conditions. Both the box-type and green house type solar dryer could dry thin slices of fish fillet in 1-3 days as opposed to the 7-9 days normally required under sun drying conditions. The quality of the dry fillet was satisfactory and CIE LAB colour values did not change significantly during drying.

scholarly journals The Trend and Status of Energy Resources and Greenhouse Gas Emissions in the Malaysia Power Generation Mix

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2200
Author(s):  
Siti Norasyiqin Abdul Latif ◽  
Meng Soon Chiong ◽  
Srithar Rajoo ◽  
Asako Takada ◽  
Yoon-Young Chun ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Energy Policy ◽  
Policy Change ◽  
Fossil Fuels ◽  
Ghg Emissions ◽  
Electricity Sector ◽  
Energy Resources ◽  
Energy Mix ◽  
Average Temperature ◽  
The Past

Environmental issues in energy policy, especially global warming, have received more attention lately than ever before. Excessive dependence on fossil fuels, deforestation, and land degradation are the three main factors that lead to increased carbon dioxide (CO2) emissions. Consequently, the global average temperature has doubled compared to anticipation. Various international protocols and agendas have been established, pledged to restore the global average temperature to the 1990 level. As a result, energy policies worldwide have also undergone various transformations to align with these protocols since then. As a developing nation, Malaysian’s electricity demand has continuously grown in the past two decades. To date, the electricity sector is still dominated by fossil fuels. Government incentives have been the most influential factor in the nation’s energy mix trend. Several energy policies implemented throughout the past 22 years have seen the shift from natural gas to coal power in power plants, and in more recent years, renewable energy resources. Numerous studies in the past have independently outlined the status of various energy source in Malaysia. However, they all fell short in providing the greenhouse gas (GHG) emissions in the Malaysian energy sector. Notably, the question that remains to be answered is how GHG emissions have changed in response to the amendment in the energy mix; hence, the effectiveness of policy change in this aspect remains unknown. This paper analysed the past and present trend of Malaysia electricity generation mix and the resultant GHG emissions. In particular, this paper focused on investigating the variation of combined specific GHG emissions in the Malaysian electricity sector, in response to the policy change within the past 22 years. This provides the insight for Malaysian policymakers to evaluate the effectiveness of past policies in GHG emissions and the measures to be taken in future. The finding of this paper shows the attention on the nation’s GHG emissions has evolved over the years, following the diversification in energy mix driven by the policy change. It was also found that, on average, it took a decade for a significant reduction in specific GHG emission to be visible since the government’s energy policy implementation.

BP Global Energy Outlook 2030

2013 ◽  
pp. 109-128 ◽  
Author(s):  
C. Rühl
Keyword(s):  
Emerging Economies ◽  
Energy Demand ◽  
Fossil Fuels ◽  
Net Energy ◽  
Global Energy ◽  
The Past ◽  
Market Shares ◽  
The Us ◽  
Almost All ◽  
Oil Gas

This paper presents the highlights of the third annual edition of the BP Energy Outlook, which sets out BP’s view of the most likely developments in global energy markets to 2030, based on up-to-date analysis and taking into account developments of the past year. The Outlook’s overall expectation for growth in global energy demand is to be 36% higher in 2030 than in 2011 and almost all the growth coming from emerging economies. It also reflects shifting expectations of the pattern of supply, with unconventional sources — shale gas and tight oil together with heavy oil and biofuels — playing an increasingly important role and, in particular, transforming the energy balance of the US. While the fuel mix is evolving, fossil fuels will continue to be dominant. Oil, gas and coal are expected to converge on market shares of around 26—28% each by 2030, and non-fossil fuels — nuclear, hydro and renewables — on a share of around 6—7% each. By 2030, increasing production and moderating demand will result in the US being 99% self-sufficient in net energy. Meanwhile, with continuing steep economic growth, major emerging economies such as China and India will become increasingly reliant on energy imports. These shifts will have major impacts on trade balances.

Konsumsi Energi Pada Alat Pengering Surya dan Tipe Bak Untuk Pengeringan Biji Kakao

2019 ◽  
Vol 17 (3) ◽  
Author(s):  
Lamhot P. Manalu
Keyword(s):  
Specific Energy ◽  
Fossil Fuels ◽  
Negative Impact ◽  
Solar Irradiation ◽  
Drying Process ◽  
Food Industries ◽  
Solar Dryer ◽  
Agricultural Applications ◽  
Drying System ◽  
Drying Efficiency

Crop drying is essential for preservation in agricultural applications. It is performed either using fossil fuels in an artificial mechanical drying process or by placing the crop under the open sun. The first method is costly and has a negative impact on the environment, while the second method is totally dependent on the weather. The drying process requires a lot of energy in relation to the amount of water that must be evaporated from the product. It is estimated that 12% of the total energy used by the food industries and agriculture absorbed in this process. Due to the limitation of energy resources, it is important to keep researching and developing of diversification and optimization of energy This study aims to assess the use of energy for cocoa drying using solar energy dryer and bin-type dryer, as well as to determine the drying efficiency of each type of dryer. The results showed that the efficiency of the solar dryer drying system ranges between 36% to 46%, while the tub-type dryers between 21.7% to 33.1%. The specific energy of solar dryer ranged from 6.17-7.87 MJ / kg, while the tub-type dryers 8.58-13.63 MJ / kg. Dryer efficiency is influenced by the level of solar irradiation and the amount of drying load, the higher the irradiation received and more cocoa beans are dried, the drying efficiency is also higher and the specific energy further down.Proses pengeringan memerlukan banyak energi sehubungan dengan banyaknya air yang harus diuapkan dari bahan yang dikeringkan. Pengeringan dapat dilakukan dengan menggunakan pengering mekanis berbahan bakar fosil atau dengan menempatkan produk di bawah matahari terbuka. Metode pertama adalah mahal dan memiliki dampak negatif pada lingkungan, sedangkan metode kedua sangat tergantung pada cuaca. Diperkirakan bahwa 12% dari total energi yang dipergunakan oleh industri pangan dan pertanian diserap untuk proses ini. Mengingat semakin terbatasnya sumber energi bahan bakar minyak maka usaha diversifikasi dan optimasi energi untuk pengeringan perlu terus diteliti dan dikembangkan. Salah satunya adalah pemanfaatan energi surya sebagai sumber energi terbarukan. Penelitian ini bertujuan untuk mengkaji penggunaan energi untuk pengeringan kakao dengan memakai pengering energi surya dan pengering tipe bak, serta untuk mengetahui efisiensi pengeringan dari masing-masing tipe pengering. Hasil kajian menunjukkan bahwa efisiensi total sistem pengeringan alat pengering surya berkisar antara 36% dan 46%, sedangkan pengering tipe bak antara 21.7% dan 33.1%. Kebutuhan energi spesifik alat pengering surya berkisar antara 6.17-7.87 MJ/kg, sedangkan alat pengering tipe bak 8.58-13.63 MJ/kg. Efisiensi alat pengering dipengaruhi oleh tingkat iradiasi surya dan jumlah beban pengeringan, semakin tinggi iradiasi yang diterima pengering serta semakin banyak biji kakao yang dikeringkan, maka efisiensi pengeringan juga semakin tinggi dan kebutuhan energi spesifik semakin turun.Keywords: energy, efficiency, cocoa, solar dryer, bin-type dryer.

Introduction

2017 ◽  
Author(s):  
Peter Rez
Keyword(s):  
Fossil Fuels ◽  
Standard Of Living ◽  
The Sun ◽  
Fundamental Physics ◽  
Atomic Nuclei

Our standard of living depends on transforming energy locked up in fossil fuels, atomic nuclei or provided free of charge by the sun and wind into a form that we can use. That transformation of energy is governed by fundamental physics and chemistry. This book is for those who want to understand more about where the energy we use comes from, and how it gets used. It lays out the simple physics behind our use of energy....

scholarly journals Trajectories of the Earth System in the Anthropocene

2018 ◽  
Vol 115 (33) ◽  
pp. 8252-8259 ◽  
Author(s):  
Will Steffen ◽  
Johan Rockström ◽  
Katherine Richardson ◽  
Timothy M. Lenton ◽  
Carl Folke ◽  
...  
Keyword(s):  
Global Economy ◽  
Human Action ◽  
Behavioral Changes ◽  
Earth System ◽  
New Governance ◽  
Sea Levels ◽  
Average Temperature ◽  
The Past ◽  
The Earth ◽  
Potential Threshold

We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a “Hothouse Earth” pathway even as human emissions are reduced. Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene. We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies. Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System—biosphere, climate, and societies—and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values.

Performance of Large-Scale Seasonal Thermal Energy Stores

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
F. Ochs ◽  
W. Heidemann ◽  
H. Müller-Steinhagen
Keyword(s):  
Thermal Energy ◽  
Large Scale ◽  
Fossil Fuels ◽  
Waste Heat ◽  
Type System ◽  
Solar Thermal Energy ◽  
Construction Costs ◽  
The Past ◽  
Energy Stores ◽  
Construction Type

More than 30 international research and pilot seasonal thermal energy stores (TESs) were realized within the past 30 years. Experiences with operation of these systems show that TES are technically feasible and work well. Seasonal storage of solar thermal energy or of waste heat from heat and power cogeneration plants can significantly contribute to substitute fossil fuels in future energy systems. However, performance with respect to thermal losses and lifetime has to be enhanced, while construction costs have to be further reduced. This paper gives an overview about the state-of-the-art of seasonal thermal energy storage with the focus on tank and pit TES construction. Aspects of TES modeling are given. Based on modeled and measured data, the influence of construction type, system configuration, and boundary conditions on thermal losses of large-scale TES is identified. The focus is on large-scale applications with tank and pit thermal energy stores and on recent investigations on suitable materials and constructions. Furthermore, experiences with the operation of these systems with respect to storage performance are discussed.

scholarly journals Theoretical Review of Secular Instabilities in the Sun

1980 ◽  
Vol 5 ◽  
pp. 441-444
Author(s):  
M. Gabriel
Keyword(s):  
Inner Core ◽  
Neutrino Flux ◽  
Radial Oscillation ◽  
Solar Model ◽  
The Sun ◽  
Standard Solar Model ◽  
The Past ◽  
Low Order

In this review we discuss the problems raised by the discovery that the sun was, in the past, unstable towards non-radial oscillations.In 1972, Fowler (1972), in an attempt to explain the low-neutrino flux measured in Davis’ experiment (now 1.6 snu, while the standard solar model predicts 4.4 snu) suggested that the sun could have undergone, some 10 years ago, a change in structure because of sudden mixing of the inner core. During the same year Dilke and Gough (1972) suggested the sun is unstable to low-order gravity modes (g+ modes) of non-radial oscillation and that the mixing is triggered when the amplitude of the oscillation becomes large enough.

Two-Dimensional InSb/GaAs- and InSb/InP-based Tandem Photovoltaic Device with Matched Bandgap

Nanoscale ◽  
2022 ◽  
Author(s):  
Meiqiu Xie ◽  
Xuhai Liu ◽  
Yang Li ◽  
Xing'ao Li
Keyword(s):  
High Performance ◽  
Fossil Fuels ◽  
Photovoltaic Device ◽  
Energy Crisis ◽  
Two Dimensional ◽  
The Past

The past several years have witnessed remarkable research efforts to develop high-performance photovoltaics (PVs), to curtail energy crisis by avoiding dependence on traditional fossil fuels. In this regard, it is...

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