Sustainable Renewable Energy Sources Research Articles

Assessing the behavior of the feed-water constituents of a pilot-scale 1000-cell-pair reverse electrodialysis with seawater and municipal wastewater effluent

Reverse electrodialysis (RED) has vast potential as a clean, nonpolluting, and sustainable renewable energy source; however, pilot-scale RED studies employing real waters remain rare. This study reports the largest RED (1000 cell pairs, 250 m2) with municipal wastewater effluent (1.3–5.7 mS/cm) and seawater (52.9–53.8 mS/cm) as feed solutions. The RED stack was operated at a velocity of 1.5 cm/s and the pilot plant produced 95.8 W of power (0.38 W/m2total membrane or 0.76 W/m2cell pair). During operation of the RED, the inlet design of the stack, comprising thin spacers, and the water dissociation reaction at the cathode were revealed as vulnerabilities of the stack. Specifically, pressure drops at the fluid inlet parts had the most detrimental effects on power output due to clogged spacers around the inlet parts. In addition, precipitates resulting in inorganic fouling were inevitable during the water dissociation reaction due to significant potential generated by the stack in the cathode chamber. Na+ and Cl− accounted for the majority of ions transferred from seawater to wastewater effluent through ion exchange membranes (IEMs). Moreover, some divalent cations in seawater, Mg2+ and Ca2+, were also transferred to the wastewater effluent. Some organics with relatively low molecular weights in the wastewater effluent passed through the IEMs, and their hydrophobic properties elevated the specific UV absorbance (SUVA) level in the seawater.

A Critical Approach on Sustainable Renewable Energy Sources in Rural Area: Evidence from North-West Region of Romania

In the favorable context of a potential increase in the use of renewable energy sources in Romania, a research was conducted among the rural population in the North-West region of development in order to analyze public perception regarding this alternative energy production. A survey was conducted on a sample of 322 respondents and data was analyzed using different statistical methods (Principal Component Analysis, Cluster analysis, etc.). Results indicated a positive attitude towards renewable energy and support mainly from young and highly educated people. The percentage of users is relatively low and there is little intention in the future to switch to a renewable energy source even if it is perceived as a sustainable way of living. Lack of knowledge regarding renewable energy sources is the most important aspect and authorities should assume a mission in the public education of citizens in order to implement the measures and achieve the goals established in the national strategy plans.

Optimizing renewable energy portfolios under uncertainty: A multi-segment fuzzy goal programming approach

Abstract Selecting a renewable energy source portfolio is an uncertain multi-criteria decision-making (MCDM) problem. In particular, it involves searching for the best portfolio of renewable energy that meets the decision maker’s preferences by considering and leveraging conflicting criteria such as technical, environmental, societal, and economic. To tackle such complex problems, this paper proposes an efficient method, called multi-segment fuzzy goal programming (MS-FGP), which addresses decision-making problems with high levels of uncertainty. The paper makes the following contributions: i) extends the conventional fuzzy goal programming (FGP) model to solve a wide range of uncertainties decision-making problems and ii) proposes a method based on a recent development in the FGP area that considers all types of fuzzy goals in real-world problems. The model is validated by applying it to a real-world scenario: optimizing the renewable portfolio for electricity generation in Italy. These renewables are solar photovoltaic (PV), wind, biomass, and tidal currents. The results show that the proposed methodology can assist decision makers in determining the most sustainable renewable energy source portfolio for electricity generation under uncertain conditions and in imprecise environments.

An Optimal Scheduling Controller for Virtual Power Plant and Microgrid Integration Using the Binary Backtracking Search Algorithm

This paper presents a novel binary backtracking search algorithm (BBSA) for an optimal scheduling controller applied to the IEEE 14-bus test system for controlling distributed generators (DGs) in microgrids (MGs) in the form of virtual power plant (VPP) toward sustainable renewable energy sources integration. The VPP and MGs models are simulated and tested based on real parameters and loads data recorded in Perlis, Malaysia, employed on each bus of the system for 24 h. BBSA optimization algorithm provides the best binary fitness function, i.e., global minimum fitness for finding the best cell to generate the optimal schedule. The fitness function is generated based on real conditions such as solar irradiation and wind speed and preparation of battery charge/discharges, fuel states and demand of the specific hour. The obtained results show that the BBSA algorithm provides the best schedule to control DGs ON and OFF based on controller decision. Results obtained from the BBSA are compared with binary particle swarm optimization in terms of objective function and power saving to validate the developed controller. The developed BBSA optimization algorithm minimizes the power generation cost, reduces power losses, delivers reliable and high-quality power to the loads, and integrates priority-based sustainable MGs into the grid. Thus, VPP can enable efficient integration of DGs and MGs into the grid by balancing their variability.

Used Cooking Oils as a Source Material for Biodiesel Production: Case Study for Kitwe Town, Zambia

The escalating prices on the world market, depreciation of fossils fuel reserves and environmental concerns has lead to the quest for the alternatives sustainable renewable energy sources. The past decades have witnessed innovations developed to produce biodiesels from various sources such as Groundnuts, Soya beans, Palm oils, Canola, Sunflower, Castor nuts and Jatropha plants and animal fats. However, most of these raw materials are competitive as food sources in human food chain. This research assesses the use of Used Cooking Oils (UCOs) from food outlets in Kitwe Town, Zambia as source for biodiesel production. Of equal importance is the assessment of environmental impact of the current waste management practices employed in disposal of UCOs. Data was obtained by administering questionnaires to various food outlets. The study revealed that approximately 8500 L/year of UCO would be generated from the sampled area. Fast food outlets accounted for 76% of the overall UCOs production in the sampled area. It was found that UCOs were mainly disposed through drainage into Municipal Sewers with the possibility of fatberg generation. Reuse of the UCO by the correspondents was a common practice and any leftover was disposed into the environment. The results of this study indicated the UCOs could be a major source material for biodiesel production.

Sustainability of Renewable Sources of Energy for Rural Communities in Anambra State

This study assessed the sustainability of different alternative renewable sources of energy for rural communities in Anambra State. Through literature review a number of sustainability criteria were established and used in assessing the identified alternative sources of renewable energy in the state. A systematic SWOT analysis was further performed to synthesise the characteristics of individual renewable energy resource. 42 experts were engaged and given a structured questionnaire where they were expected to score each of the renewable energy sources on a 5-point scale based on the selected sustainability criteria. A scale of 1-5 was used to examine and rate the sustainability of each of the identified renewable energy options based on environmental social and economic criteria. Based on their individual scores, the total average score for each of the energy sources was computed and used in rating their level sustainability. The study found that among the six alternative renewable energy options considered, biomass was ranked the most sustainable renewable energy source for electricity provision in rural communities in the state with a sustainability score of 35.0. Solar and hydro energy resources were ranked 2nd and 3rd with scores of 31.2 and 31.0 respectively, while geothermal (24.5) energy was ranked the least. This implies that harnessing and investing in biomass, solar and hydro energy technologies in Anambra State could lead to sustainable energy provision in the rural Communities in Anambra State. The study further avers that genuine commitment through government investments in biomass, solar and hydro energy technologies with strong policy framework could minimise the electricity challenges of the rural communities in the state, and at the same time reduce pressure on urban infrastructure due to rural-urban migration.

Nanostructured Metal Chalcogenides for Energy Storage and Electrocatalysis

Energy storage and conversion technologies are vital to the efficient utilization of sustainable renewable energy sources. Rechargeable lithium‐ion batteries (LIBs) and the emerging sodium‐ion batteries (SIBs) are considered as two of the most promising energy storage devices, and electrocatalysis processes play critical roles in energy conversion techniques that achieve mutual transformation between renewable electricity and chemical energies. It has been demonstrated that nanostructured metal chalcogenides including metal sulfides and metal selenides show great potential for efficient energy storage and conversion due to their unique physicochemical properties. In this feature article, the recent research progress on nanostructured metal sulfides and metal selenides for application in SIBs/LIBs and hydrogen/oxygen electrocatalysis (hydrogen evolution reaction, oxygen evolution reaction, and oxygen reduction reaction) is summarized and discussed. The corresponding electrochemical mechanisms, critical issues, and effective strategies towards performance improvement are presented. Finally, the remaining challenges and perspectives for the future development of metal chalcogenides in the energy research field are proposed.

A simple lower bound on the EROI of photovoltaic electricity generation

Two conceptually and computationally simple techniques (one optimistic, the other pessimistic) are introduced to estimate the energy payback time of a photovoltaic array. Both yield values of the Energy Returned On energy Invested (EROI) in excess of approximately 5. Therefore solar photovoltaic electricity appears to be a stably sustainable source of renewable energy.

Self-sustaining Microbial Photoelectrosynthesis for Hydrogen Generation and Waste Water Cleaning

Sunlight offers an inexhaustible and sustainable source of renewable energy to meet our increasing energy demand. However, direct harvesting of solar energy is still challenging due to the variation of natural sunlight and its intermittent nature. To meet the Terawatt Challenge and harness large quantity of energy, current artificial photosynthesis system is showing great promise for its capability of imitating natural photosynthesis. However, the direct water splitting by artificial photosynthesis requires large energy input. Here we demonstrate GaInP2-TiO2-MoSx photocathode could couple with microbial electrochemical oxidation process, which used to treat wastewater and recover the chemical energy embedded in organics into electricity, to covert water into hydrogen. The self-sustaining system could generate a current of 0.4 mA/cm2 without any external bias and ~10 mA/cm2(with 5 % solar to hydrogen conversion efficiency) at slightly applied bias condition.

Environmental aspects of the geothermal energy utilisation in Poland

Geothermal energy is considered as a strategic and sustainable source of renewable energy that can be effectively managed in several economic sectors. In Poland, despite the abundant potential of such resources, its share in the energy mix of renewable energy sources remains insubstantial. The utilisation of geothermal resources in Poland is related to the hydrogeothermal resources, however, numerous researches related to petrogeothermal energy resources are being performed. The utilisation of each type of energy, including geothermal, has an impact on the natural environment. In case of the effective development of geothermal energy resources, many environmental benefits are pointed out. The primary one is the extraction of clean, green energy that is characterised by the zero-emission rate of pollutants into the atmosphere, what considering the current environmental pollution in many Polish cities remains the extremely important issue. On the other hand, the utilisation of geothermal energy might influence the natural environment negatively. Beginning from the phase of drilling, which strongly interferes with the local landscape or acoustic climate, to the stage of energy exploitation. It should be noted that the efficient and sustainable use of geothermal energy resources is closely linked with the current law regulations at national and European level.

A REVIEW OF GLOBAL SCENARIO OF BIODIESEL, SOURCES AND SLUDGE PALM OIL WASTE FOR THE BIODIESEL PRODUCTION

The uncontrolled usage of fossil fuel and its by-products has largely contributed to global warming which is by far irreversible; these non-renewable reserves if exhausted might have a major impact on human development. This urges the need of discovering a sustainable renewable energy source which could potentially replace the fossil fuel in future, this is also the main focus researchers working on field of energy. A more sustainable biodiesel, which also is biodegradable and a clean energy has drawn a significant amount of attention and interest across the globe in recent years. Steady raise in the price of petroleum products and importantly the environmental concerns, highlighted the need of alternative fuels. Biodiesel primarily consists of Fatty Acid Methyl Esters (FAME), which are derived through transesterification of various sources such as vegetable oils, animal fat etc. In addition, the recycled oil from the food industry when processed with a suitable catalyst along with methanol produces mono alkyl esters, which are further segregated and purified. Bio-diesel can be produced through many techniques including acid & base catalysis, enzymatic conversion, solid catalysis, non-catalytic conversion and super-critical methanolysis. Multiple factors such as, amount of alcohol, catalysts and reaction temperature, reaction time and FFA and water content of oils or fats impact the transesterification reaction. The multiple advantages of Biodiesel include safety, non-toxicity and biodegradable in comparison with petroleum based products, thus justifying its title as “Green fuel”. The reduced polluting ability of Biofuels is due to the fact that they are oxygenated and are relatively free of sulfur and other aromatic compounds, thus being a effective fuel with reduced emission of Sulfuric oxides, Carbon monoxide, residual hydrocarbons and particulate matter. Thus no engine modification is required with the prior blending proportion with normal petroleum diesel. The major physicochemical properties are similar between biodiesel and the petroleum fuel. The present review made an attempt to cover the scenario of worldwide concerned towards biodiesel production, its scope and need, various sources adopted for biodiesel preparation, the various catalysts, reaction condition adopted, maintained during production of biodiesel and its fuel properties (depends on Free Fatty Acid profile of the feedstock) and an exclusive role of Sludge Palm Oil (SPO) form palm oil processing industries, a cost effective feedstock for biodiesel preparation.

Biomass traits and candidate genes for bioenergy revealed through association genetics in coppiced European Populus nigra (L.).

BackgroundSecond generation (2G) bioenergy from lignocellulosic feedstocks has the potential to develop as a sustainable source of renewable energy; however, significant hurdles still remain for large-scale commercialisation. Populus is considered as a promising 2G feedstock and understanding the genetic basis of biomass yield and feedstock quality are a research priority in this model tree species.ResultsWe report the first coppiced biomass study for 714 members of a wide population of European black poplar (Populus nigra L.), a native European tree, selected from 20 river populations ranging in latitude and longitude between 40.5 and 52.1°N and 1.0 and 16.4°E, respectively. When grown at a single site in southern UK, significant Site of Origin (SO) effects were seen for 14 of the 15 directly measured or derived traits including biomass yield, leaf area and stomatal index. There was significant correlation (p < 0.001) between biomass yield traits over 3 years of harvest which identified leaf size and cell production as strong predictors of biomass yield. A 12 K Illumina genotyping array (constructed from 10,331 SNPs in 14 QTL regions and 4648 genes) highlighted significant population genetic structure with pairwise FST showing strong differentiation (p < 0.001) between the Spanish and Italian subpopulations. Robust associations reaching genome-wide significance are reported for main stem height and cell number per leaf; two traits tightly linked to biomass yield. These genotyping and phenotypic data were also used to show the presence of significant isolation by distance (IBD) and isolation by adaption (IBA) within this population.ConclusionsThe three associations identified reaching genome-wide significance at p < 0.05 include a transcription factor; a putative stress response gene and a gene of unknown function. None of them have been previously linked to bioenergy yield; were shown to be differentially expressed in a panel of three selected genotypes from the collection and represent exciting, novel candidates for further study in a bioenergy tree native to Europe and Euro-Asia. A further 26 markers (22 genes) were found to reach putative significance and are also of interest for biomass yield, leaf area, epidermal cell expansion and stomatal patterning. This research on European P. nigra provides an important foundation for the development of commercial native trees for bioenergy and for advanced, molecular breeding in these species.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-016-0603-1) contains supplementary material, which is available to authorized users.

Multicriteria decision support in local energy planning: An evaluation of alternative scenarios for the Sustainable Energy Action Plan

One of the major challenges for the implementation of local energy planning is the successful development of a Sustainable Energy Action Plan (SEAP) by the local authorities (especially within the framework of their participation to the Covenant of Mayors’ initiative). This aspect constitutes a decision making problem, since the local authorities have to identify the best fields of actions and opportunities for reaching their long-term CO2 reduction target. However, the already available methods and tools do not offer an integrated framework for the SEAPs’ development and especially the selection of sustainable Renewable Energy Sources (RES) and Rational Use of Energy (RUE) technologies. In this context, the aim of this paper is to present a participatory supportive framework for the implementation of local energy planning. At the first level, the proposed approach incorporates the development of alternative Scenarios of Actions (using knowledge-based process, participatory approach and aspiration level). At the second level, a direct and transparent multicriteria decision support is introduced, in order to evaluate the feasible Scenarios. It includes the application of a multicriteria ordinal regression approach and an extreme ranking analysis method for the estimation of the best and worst possible ranking position of each Scenario. The results from the pilot appraisal of the methodological approach to a “real” problem are presented and discussed. The adopted approach contributes to the selection of the most appropriate combination of RES/RUE actions, supporting in this way the local authorities to the development of their SEAP.

Land use change (LUC) analysis and life cycle assessment (LCA) of Brazilian soybean biodiesel

Biodiesel is an alternative to tackle global warming, especially for reducing greenhouse gases (GHG) emissions when replacing fossil fuels. However, it can compete for land with food production. Brazil is a global player on soybeans farming and most of the biodiesel produced in the country comes from it. This work proposes a new approach to evaluate its impact, associating land use change (LUC) analysis with life cycle assessment (LCA) in a representative Brazilian soybeans farming zone. LUC assessment used Landsat satellite imagery analysis from the years 1993 and 2013, and intergovernmental panel on climate change (IPCC) guidelines to estimate GHG emissions. LCA was based on field data collection processed with SimaPro®. Results show that the increment on annual GHG emissions per hectare, derived from the apportioning total emissions for the period studied, was 50.16 kg CO2 eq ha−1 y−1. From this increment, 97.1 % come from LUC, being the largest share from converting pastures to soybeans farming (81.2 % of the total emissions). However, in the area, a large share of converted pastures are degraded, acting as source of emissions, not as sink as considered by IPCC. At the same time, practices like no-tillage make soybeans a carbon sink. Therefore, results could change if alternative approaches were to be adopted, being a challenge for future work. Therefore, when considering biodiesel from soybeans, a close regard to local land use dynamics is essential to evaluate impacts. Besides, promoting more efficient use of land already cleared with the goal to avoid deforestation can turn biodiesel into a sustainable renewable energy source.

Energetic Communities: Planning support for sustainable energy transition in small- and medium-sized communities

Energetic Communities: Planning support for sustainable energy transition in small- and medium-sized communities

Energetic Communities: Planning support for sustainable energy transition in small- and medium-sized communities

Energetic Communities: Planning support for sustainable energy transition in small- and medium-sized communities

Energetic Communities: Planning support for sustainable energy transition in small- and medium-sized communities

Energetic Communities: Planning support for sustainable energy transition in small- and medium-sized communities

Energetic Communities

Energetic Communities

ELECTRICITY GENERATION FROM SUGAR PROCESSING WASTEWATER USING ENVIRONMENTAL FRIENDLY DUAL CHAMBER MICROBIAL FUEL CELL

Energy crises in Pakistan are evaluated in terms of inclination since last few years and these crises mainly dependable on the depletion of petroleum. The focus of world is diverting towards the sustainable renewable energy sources. Microbial fuel cell is one of the emerging technologies that use the concept of clean energy using environmental friendly process with the utilization of microbes. In this research a microbial activity is observed that generates electricity from sugar processing wastewater using a dual chamber microbiological reactor. Different observations has been carried out to analyze the wastewater and microbiological parameters with respect to time and it was analyzed that fuel cell generates electricity of 1.28 mA, 0.9 volts and 0.304 Watt/m 2 . Along with the energy generation, the waste water is also treated with this microbial cell having effectiveness of TDS 56.35%, COD 69.3% and BOD 68.1% removal. Due to this efficiency, the microbial fuel cell may replace the conventional harmful energy sources.

Prospects of geothermal water Use in cultivation of Spirulina

Abstract Spirulina has been studied due to its commercial importance as a source of essential amino acids, protein, vitamins, fatty acids etc. Most of the culture systems in use today are open ponds. The new approach proposed in this paper is to use the geothermal water as a medium for microalgae cultivation. Poland has beneficial conditions for wide geothermal use, as one of the environmentally friendly and sustainable renewable energy sources. In the planned research, geothermal water could be used to prepare microalgal culture medium, to heat greenhouses with bioreactors used for the growth of Spirulina, to dry the obtained biomass, as well as to heat the ground in foil tunnels. Using geothermal water gives the possibility to produce algae in open ponds covered with greenhouses and to cultivate plants during winter. The obtained algae can be used for the production of algal bio-products (e.g. homogenates), having the potential application in plant cultivation.