Alternative Renewable Energy Sources Research Articles

Effect of Dust and High Temperature on Photovoltaics Performance in the New Capital Area

The trend for integrating solar Photovoltaic Panels as an alternative renewable and sustainable energy source is growing in Egypt, North Africa and the Middle East. However, these efforts are not widely accepted by the society due to their lower efficiencies. The efficiency of the photovoltaic panels is affected by many environmental parameters, which have a negative impact on system efficiency and cost of energy, dust and increased panel temperatures being the most serious. This work presents the results of a case study conducted at The British University in Egypt at El-Sherouk city to study the effect of different parameters such as dust accumulation, water cooling and coating on their performance of both mono- and poly-crystalline panels at El-Sherouk City. The effects of high temperature and dust accumulation on different solar panels placed in natural outdoor conditions at El-Sherouk City were studied and the electrical performance of dusted, cleaned, and cooled PV panels is presented. The variation in the efficiency of mono-crystalline panels installed at different tilt angles, resulting from the accumulation of dust on their surface, was also studied. The results showed that the accumulation of dust on the surface of different types of solar panels can reduce the efficiency by 30%. While the high temperature can reduce the efficiency by up to 10 %. The results showed that the power reduction percentage was 17%, 20%, 25%, 27% and 30% for tilt angles 60°,45°,30°,15° and 0°; respectively. Tilt angles 15° and 30° showed to be optimal for the installation of the PV solar system, as they resulted the highest amount of output power

Research Survey on Different MPP Tracking Optimization Algorithms for Solar Photovoltaic System (SPS)

Due to increase in global warming, it is required to choose an alternative renewable energy source for the electricity generation. Among various renewable energy sources (RES), photo-voltaic energy is one of the most accessible source of energies. But the conversion rate of solar PV cell is about 25 % to 40 % of solar irradiation level. In Solar Photovoltaic (PV) system, to improve and maximize the operating efficiency level, Maximum Power Point Tracking (MPPT) techniques were required. Because of the change in the level of solar irradiance, and the nature of dynamic temperature, this MPP tracking will be highly important to make the solar PV system (SPS) to operate at higher efficiency level. This MPPT method is mainly categorized into three different types such as direct method, indirect method and intelligent method. This paper will gives and overview about various MPPT methods employed for solar PV system. Various controlling algorithms were discussed in this section for a better understanding.

Co-digestion of cocoa pods and cocoa leaves: Effect of C/N ratio to biogas and energy potential

In Indonesia, energy needs are mostly fulfilled by non-renewable fuels. In the longer term, such practices may lead to an energy crisis due to problems of resource continuity and availability. Therefore, the development of renewable energy remains a priority for the Indonesian Government, one of which is from biomass sources. Indonesia has vast and abundant biomass sources available for further transformation to bioenergy. Waste from the cocoa plantation (e.g. cocoa pods and cocoa leaves), for instance, contain organic materials that are potential for biogas production. This research aimed to evaluate the effect of the C/N ratio on biogas production and energy potential from the co-digestion of cocoa husk with cocoa leaves. The Biochemical Methane Potential (BMP) test operated under batch and mesophilic condition for 28 days were carried out. The samples tested include blank control, positive control (α-cellulose), and co-digestion samples at different C/N ratio in the range of 22 to 25, prepared in triplicate. The results indicated that pH inhibition was not evident during the digestion process. The findings also confirmed that the co-digestion of cocoa pods with cocoa leaves at a much higher C/N ratio was able to enhance biogas production. Further estimation on the electricity potential showed a potential application of this co-digestion strategy for providing alternative renewable energy sources.

Editorial preface of the special issue on “progress in alternative fuels and energies”

Editorial preface of the special issue on “progress in alternative fuels and energies”

Environmental, social and health benefits of alternative renewable energy sources. Case study for household biogas digesters in rural areas

In rural areas of Colombia, liquefied petroleum gas (LPG) is the preferred option available for cooking. However, the poorest households rely on firewood (FW) to meet their daily cooking needs, because is the most accessible and affordable energy source. This high level of dependence on traditional solid fuels and the use of non-optimized cook stoves results in high health, environmental, economic and social costs on developing countries’ households. This study aimed at assessing the environmental and health benefits of implementing grass-fed household biogas digesters in rural areas of Colombia, through Life Cycle Assessment (LCA) methodology. Functional Unit was the annual demand of cooking energy by a typical family in those rural areas, which means 2400 MJ of useful heat. There were evaluated two sources of biogas obtained from Pennisetum grass: Biogas from minerally fertilized grass (BMFG) and from organically fertilized one (BOFG). Results showed that FW had the highest impacts from fuels assessed, while the lowest impacts were found with BOFG, showing half of LCA total impacts compared with LPG and more than two orders of magnitude lower in non-methane volatile organic compounds and particulate matter (PM2.5eq) emitted compared with FW. Therefore, BOFG appears as an environmentally feasible alternative for cooking, which allowed the reduction LCA impacts among most of the categories assessed, as the fuel purchase expenses and of the wood collection time. Moreover, health impacts including the indoor emissions exposure showed also more than two orders of magnitude less impact compared with FW. It can be concluded that household digesters could improve the living standard of rural families.

Heat of Combustion of Coffee Pulp and Husks as Alternative Sources of Renewable Energy

The study determined the amount of heat energy (heat of combustion) produced per unit mass from coffee pulp and coffee husks to see if these can be used as alternative sources of energy. The samples were obtained from Mount Elgon areas in Eastern Uganda. The objectives determined the amount of heat produced per unit mass from coffee husk and pulp and compared the amount of heat produced per unit mass from the coffee husk and coffee pulp. The coffee husk and pulp were dried, ground and sieved using a 150 microns diameter sieve. The resultant powder was analyzed using IKA C200 bomb calorimeter. The Heat values produced per unit mass from coffee husk and pulp were 15.389KJg-1 and 13.755KJg-1 respectively. Further analysis showed that both coffee pulp and coffee husks could be used as fuels for renewable energy. However, from the findings, it is recommended that coffee husks should be preferred as a better source of fuel since it generated 1.634KJg-1 more energy than the coffee pulp. Comprehensive study should be carried out on the two samples to obtain a complete fuel description of the samples.

Principles and practice of designing microbial biocatalysts for fuel and chemical production.

The finite nature of fossil fuels and the environmental impact of its use have raised interest in alternate renewable energy sources. Specifically, nonfood carbohydrates, such as lignocellulosic biomass, can be used to produce next generation biofuels, including cellulosic ethanol and other nonethanol fuels like butanol. However, currently there is no native microorganism that can ferment all lignocellulosic sugars to fuel molecules. Thus, research is focused on engineering improved microbial biocatalysts for production of liquid fuels at high productivity, titer, and yield. A clear understanding and application of the basic principles of microbial physiology and biochemistry are crucial to achieve this goal. In this review, we present and discuss the construction of microbial biocatalysts that integrate these principles with ethanol-producing Escherichia coli as an example of metabolic engineering. These principles also apply to fermentation of lignocellulosic sugars to other chemicals that are currently produced from petroleum.

Application of metallic nanoparticles for biogas enhancement using the biomethane potential test

Owing to the continued global environmental crisis, wastewater treatment is seen with great potential to limit the demand on freshwater usage while contributing to depletion of global warming with alternative source of renewable energy. Thus, in the wastewater settings, anaerobic digestion (AD) reduces organic pollutants while generating green energy in the form of biogas. However, AD is a relatively slow microbial–based process, which has become a major challenge to produced methane–enriched biogas. Therefore, augmentation of AD was investigated via the addition of metallic–based nanoparticles (NPs) (Fe, Cu, and Ni) at a concentration of 1 g and 2 g. Scanning electron microscopy and energy dispersive X-ray (SEM/EDX) were used to track the NPs distribution and utilisation in the post-AD digestate. A biomethane potential (BMP) technique was employed with 1 L Duran schott bottles. This was operated at a working volume of 0.8 L (0.3 L inoculum and 0.5 L wastewater), hydraulic retention time of 10 days and mesophilic temperature 40 °C. The wastewater treatability performance showed over 65% removal of chemical oxygen demand (COD), turbidity and colour. The NP additives showed a synergetic effect on biogas production as it hinged on the NPs type and concentration (1 g Fe-NPs > 2 g FeNiCu-NPs > 1 g Cu-NPs > 2 g Cu-NPs > 1 g Ni-NPs > 2 g Ni-NPs > 2 g Fe-NPs). Usage of 1 g of Fe NPs balanced the nutrient supply of the microbes, which increased the biogas production (by 75% >3 mL/d of the control) with 100% methane composition. The prospects of Fe-based NPs seems very promising and industrially worthy for wastewater treatment and bioenergy production. This warrants future research into NPs recovery and reuse as a way of mitigating its economic viability and environmental risk.

Origin of the contact force-dependent response of triboelectric nanogenerators

Triboelectric nanogenerators (TENGs) have attracted significant interest as the alternative source of renewable energy. Their performance is believed to depend on the contact force, but its origin is yet to be established. Herein, we show that the origin lies in the real contact area A r , probed with novel experiments specifically designed for this purpose. The open circuit voltage V oc , short circuit current I sc and A r for a TENG, having two nominally flat tribo-contact surfaces, were found to increase with contact force/pressure. The A r is notably small at low pressures (0.25% at 16 kPa) that are typically experienced in wearable applications. However, it increases 328 fold to as much as 82% when it saturates beyond about 1.12 MPa pressure - achievable for impact with ocean waves. Critically, V oc and I sc saturate at the same contact pressure as A r suggesting that electrical output follows the evolution of the A r . Assuming that tribo-charges can only transfer across the interface at areas of real contact, it follows that an increasing A r with contact pressure should produce a corresponding increase in the electrical output. These results underline the importance of accounting for real contact area in TENG design to boost their performance, the distinction between real and nominal contact area in tribo-charge density definition, and the possibility of using TENGs as a self-powered pressure/load sensors. Crucially, the results indicate that the large contact pressures, readily available in applications such as road-tyre contact and wave energy, alone could be enough to boost the performance, thus avoiding the need for costly surface engineering to increase A r . • Origin of the contact force-dependent performance of TENGs investigated. • Real contact area & electrical output measured over wide contact force range. • Origin is contact force-dependent real contact area owing to surface roughness. • Major implications for definition & measurement of tribocharge density. • Major implications in TENG design, pressure sensor design & high force applications.

Evaluation of the design and performance of a micro hydropower plant in a pressurised irrigation network: Real world application at farm-level in Southern Spain

Agriculture is one of the most energy intensive activities within the European Union. The common absence of electric infrastructure in these rural settings has led to the need for in situ generation in many cases. The existing excess pressures in large pressurised irrigation networks makes the generation of micro hydropower here a possible alternative renewable energy source. Pump-as-turbines have been proposed as a cost-effective technology for such purposes, taking advantage of the excess pressure in pipe networks to produce energy. This paper presents a methodology for the design of a plant for micro hydropower generation in an agricultural farm and outlines the predicted benefits of the installation. These predicted benefits were also compared with the measured performance of the plant for the 2019 irrigation season. The main aim of the plant was to replace a diesel generator that supplied energy to the farm. The excess pressure found in the pipe network varied between 0m and almost 60m. The nominal power of the pump-as-turbine was selected to supply the maximum energy requirements of the farm. The predicted operation time of the plant was estimated at up to 3199 h concentrated between April and September. An annual savings of approximately €2950 and 11 t eCO2 were also estimated. The measured results showed an actual operation time of 2443 h between May and September, as in April the monitoring system was not operational. For this operation time, the savings were €2258 and 8.4 t eCO2. Considering the April theoretical irrigation time obtained, the savings raised up to approximately €2434 and 9.1 teCO2. The return on investment of the installation was computed to be recovered in less than ten years.

A study of enhancing the biogas production in anaerobic digestion

Anaerobic digestion is one of the main strategies for waste management that eliminates waste and produces biogas simultaneously. Biogas is an alternative source of renewable energy consisting mainly of methane and carbon dioxide. This is suitable for transport applications, energy production and cooking. The present study provides a comprehensive overview on biogas production enhancement techniques in anaerobic digestion from various biomass wastes. Co-digestion, two phase digestion, recirculation of slurry, thermal pretreatment, alkaline pretreatment, acid pretreatment, ultrasound pretreatment, hydrothermal pretreatment and milling pretreatment are some of the techniques used to improve the biogas production. Comparatively co-digestion significantly improves the biogas production than the other processes which gives the biogas production of 531 Lkg−1VS with 52% cow manure and 48% food wastes in a 30-day hydraulic retention period. Pre-treatment before anaerobic digestion increases the biogas yield, especially hydrothermal pretreatment of rice straw increases the yield of biogas from 140 to 315.9 Lkg−1VS. In addition, thermal and mechanical pretreatment of barley straw increases the biogas production by 40.8% and 50.2% respectively. Information on different biomass waste components is important for the efficient implementation of anaerobic digestion and maintaining the key parameters within the desired range will also boost the biogas production.

Economic assessment of the use of household waste as an alternative renewable energy source

Economic assessment of the use of household waste as an alternative renewable energy source

Marketing Strategies to Use Solar Energy in Homes

Grounded in the disruptive innovation theory in this single case study, the purpose of this case study was to explore homeowner’s awareness of the benefits of solar energy. Twenty residential homeowners were interviewed face- to-face to explore: 1) perceived benefits of solar energy in their county in Ohio and 2) perceptions of the rationale behind the marketing strategy of solar energy systems sold for residential use. Inductive analyses and coding interpretation to explore the participants’ responses revealed 3 themes: the existence of environmental benefits for using solar energy systems, the expensive cost of equipment associated with government incentives, and the lack of marketing information available for consumers use. The study’s finding indicated that homeowners were largely unaware of the lack of marketing strategies and social change implications through community awareness. The implications for positive social change include the potential to enable corporate leaders, small business owners, and entrepreneurs to develop marketing strategies for renewable energy systems. These strategies may promote solar energy systems as a clean, renewable, and affordable alternative electrical energy source for the 21st century.

Evaluation of Bioethanol Production from Enset (<i>Ensete ventricosum</i> (Welw.) Cheesman) Processing Waste and Leaf Using <i>Saccharomyces cerevisiae</i>

The depletion of fossil fuel reserves and the increasing awareness of greenhouse gas emissions act as the primary driving force for finding alternative renewable energy sources, especially those derived from biomass. This study was conducted with the objective of bio-ethanol production from non- edible plant biomass, Enset [Ensete ventricosum (Welw.) Cheesman] processing waste and leaves in batch fermentation using yeas (S. cerevisiae). Forty grams of acid pre-treated or untreated ensete processing waste and leaves were incubated with 1% of yeast under three different temperature (26°C, 30°C and 40°C) treatments and allowed to ferment over 16 days. Yeast cell density, total reducing sugars and percent of ethanol was measured at 4 days interval spectrophotometrically beginning from the incubation period. Results showed that all measured parameters subsequently decrease with increasing days of fermentation in both acid pre-treated and untreated substrates. Acid pre-treated substrates resulted in higher amounts of cell density, total reducing sugars and bio-ethanol than untreated substrates. Among the different temperatures, 30°C produced more bio-ethanol than others throughout the fermentation periods, and the result was in agreement with cell density and total sugars measured. In conclusion, this study showed that Enset processing waste and leaves can be used as a feedstock for bio-ethanol production and the yield can be increased with acid pre-treatment and incubation under 30°C temperature.

Суперконденсаторні енергонакопичувачі для освітлювальних систем з комбінованим електроживленням

Modern continuous lighting systems use powerful high-performance LEDs as light sources and an important task is to begin using alternative renewable energy sources for their power supply (including during the day). The simplest of the renewable energy sources is photovoltaic solar energy converter. However, solar photovoltaic generation depends significantly on many factors - geographical location, time of day, state of the atmosphere, time of year and the like. In addition, photovoltaic generation depends on the weather conditions and cloudiness, which makes it unstable and prone to change drastically (by an order of magnitude) during daylight hours. Therefore, an important element of the power system based on renewable energy sources is the system of accumulation of generated energy. The method of power stabilization using supercapacitors for systems with a significant change in power generation in the electrical power system is analyzed. The paper offers design principles of the power supply systems for powerful LEDs with supercapacitor energy storage devices intended to make the use of energy from sources with variable generation more efficient. The systems with supercapacitor-based drives, which allow to ensure stable operation of the lighting system when the power supply from an alternative source is absent or reduced, provide high safety and reliability, and have a significantly longer service life than battery-based energy storage systems.

Vertical axis wind power plant

The issue of developing technologies using alternative renewable energy sources today is a very urgent task both around the world and in Russia, which is explained by economic, technological, and, most importantly, environmental factors. The climatic and geo-graphical features of our country create all the necessary conditions for the use of such areas as solar energy, small hydro energy, wind energy, etc. But the most promising in terms of energy potential is wind energy, as many regions of our country are located in areas with high average wind speeds. However, there are a number of problems that impede the development of wind energy in Russia, the most important of which is the almost complete absence of wind generators designed and manufactured in our country that could compete with foreign models. The product proposed in the article is an attempt to solve this problem through the use of a new design of a wind wheel and an electric generator, as well as the use of magnetic suspensions.

PERIODE PEMBUNGAAN DAN PEMBUAHAN NYAMPLUNG (Calophyllum inophyllum) PADA TEGAKAN BENIH PROVENAN DI WONOGIRI

Nyamplung (Calophyllum inophyllum) is a potential type of non-timber forest product (NTFP) with high oil yield which is useful as an alternative renewable energy sources and herbal medicine-cosmetics. Result of population selection level in Java Island have been used to build Provenan Seed Stand (PSS) nyamplung in KHDTK Wonogiri (Central Java) as an improved seed source with high oil yield and fruit productivity. Seed become nyamplung part that is used as oil raw material which is strongly influenced by flowering and fruiting period. Information on flowering fruiting ability and period is needed to support the availability of raw materials in a sustainable supply for the nyamplung oil industry. Seed become nyamplung part that is used as oil raw material which is strongly influenced by flowering and fruiting period. Information on flowering fruiting ability and period is needed to support the availability of raw materials in a sustainable supply for the nyamplung oil industry. Observation of flowering and fruiting period focused on 465 individual trees in nyamplung PSS at KHDTK Wonogiri through monthly monitoring by calculated flowering fruiting individual tree during 5 years (2014-2018). The results showed that the flowering period of nyamplung in TBP Wonogiri varied during 2014-2018. Flowering and fruiting occurs almost throughout the year. However, the peak of flowering and fruiting occurs mostly in March-August (end of the rainy season to the middle of dry season). In general, the trend of flowering and fertilization increased in 2014-2016, then decreased in 2017-2018, which is thought to be influenced by the higher canopy density. The environmental factor that most influences flowering is number of rainy days, while fertilization of TBP was strongly influenced by temperature. The management of TBP require future action such: second thinning, top pruning, application of fertilizers and hormones to stimulate flowering, and further detailed observations of flowering fruiting stage and its interaction with microclimate.

ENERGY PLANTS ALTERNATIVE TO FUTURE BIOFUEL PRODUCTION

Replacing fossil fuels with alternative renewable energy sources is a very current issue worldwide. The development of energy plant (lingo-cellulosic) crops represents the promising solution, for the future production of biofuels in order to produce renewable energy and replace fossil fuels. For the implementation of energy crops were elaborated a series of technologies and technical equipment that respond to the requirements of these crops. The paper addresses these technologies, technical equipment and technologies for valorizing energy crops.

ДОСЛІДЖЕННЯ ПРОЦЕСУ ПРИГОТУВАННЯ СУШИЛЬНОГО АГЕНТА У СОНЯЧНОМУ ТЕПЛОВОМУ КОЛЕКТОРІ ІЗ ВИКОРИСТАННЯМ 3D-МОДЕЛЮВАННЯ

Сушіння сільськогосподарської продукції є однією із найбільш енергоємних операцій під час первинної обробки сировини. Зменшення витрат на процес сушіння суттєво впливає на вартість кінцевого продукту. Тому надзвичайно актуальним є використання сонячної енергії для приготування сушильного агента. У статті, використовуючи програмне забезпечення тримірного моделювання, досліджено процес нагрівання сушильного агента в сонячному тепловому колекторі. Використовуючи технологію “цифровий двійник”, досліджено режими роботи сонячного теплового колектора із різними геометричними параметрами. Реалізацію технології “цифровий двійник” здійснювали за допомогою програмного комплекса Creo 7.0 із встановленим модулем комп’ютерної симуляції FloEFD. Для комп’ютерної симуляції процесу нагрівання сушильного агента у колекторі були задані такі параметри: час проведення експерименту, місце розташування об’єкта дослідження, положення відносно вибраної системи координат (кути нахилу до горизонту), температура навколишнього середовища, хмарність. Використання технології “цифровий двійник” дозволило оптимізувати параметри сонячного теплового колектора та скоротити матеріальні витрати і тривалість дослідження. На кінцевому етапі досліджень було перевірено остаточно вибраний варіант конструкції колектора. Розроблена комп’ютерна модель буде використана для автоматизованого керування сонячним тепловим колектором та оптимізації процесу сушіння.

Density Functional Theory Investigation of Fulvene-Derivatized Fullerenes as Candidates for Organic Solar Cells.

Interest within the scientific community in organic solar cells has been on the rise over the last two decades as researchers respond to increasing demands for alternative renewable energy sources. Fulvene, fullerene, and endohedral metallofullerene derivatives have individually shown great promise as efficient charge transfer agents. Despite the heavy demand for research in this area, there have been no studies reported to date that explore the electronic behavior of molecules containing both fullerene and fulvene groups. The lack of interest may be attributed to inherent limitations and inaccuracy in most density functional theory (DFT) band gap calculations for large molecules. Herein we present a systematic computational investigation of the band gaps and dipole moments of several test fullerene-fulvene molecules using a novel DFT method that has been modified to allow accurate computation of the band gaps of this class of molecules. Calculated results showed promising low band gap energies and attractive conductive properties for all fullerene-fulvene derivatives. This new DFT method can conceivably be an invaluable tool that can provide predictive insight into the suitability of similar high molecular weight materials for application in organic solar cell devices.