Sustainable Alternative Energy Source Research Articles

Direct Conversion of Natural Date Pulp to Hierarchically Porous Carbon Spheres As Efficient and Stable Oxygen-Reduction Electrocatalysts

The impending global energy crisis and environmental concerns associated with the excessive use of fossil fuels have prompted us to explore highly sustainable alternative energy sources as well as highly efficient eco-friendly energy conversion and storage technologies. Fuel cells are electrochemical energy conversion devices with energy conversion efficiencies two times greater than those of conventional fire powered plants. Such electrochemical devices normally involve an oxygen reduction reaction (ORR) over their positive electrode; unfortunately, the sluggish ORR kinetics at room temperature significantly limit their efficiency and performance, and thus have become a major obstacle towards their practical applications. The development of efficient electrocatalysts for promoting the ORR is the key to realize the practical use of such advanced technologie. Carbon materials are promising alternatives to noble metal catalysts for oxygen reduction reactions (ORR) in energy conversion devices. Here we report hierarchically porous carbon spheres with a trace amount of encapsulated cobalt as highly active and stable electrocatalysts for the ORR under both alkaline and acidic conditions. We use renewable natural date pulp as the carbon precursor and a facile hydrothermal carbonization method with in situ formed cobalt as a template for the synthesis. These catalysts yield competitive catalytic activity (a small Tafel slope of 53 mV dec-1) and superb durability and methanol tolerance compared to the benchmark Pt/C catalyst in alkaline electrolyte. Even under harsh acidic conditions, the catalysts deliver a satisfactory catalytic performance and good stability, indicating their extensive applicability. This performance is mainly attributed to the rich surface defects and the hierarchically porous structure that provide abundant active sites for the ORR. In situ formed cobalt nanoparticles are critical to the creation of the abundant mesopores, high specific surface area, and catalytically active defect sites over the carbon material. The encapsulated cobalt residual further enhances the ORR activity of the catalysts, while having a negligible effect on the cost due to its trace level (0.2 at.%).

Hole Transporting Layers in Solar Cells: Stabilizing NiO Perovskite Inks with Organic Capping Agents

Increasing global demand for inexpensive energy has stimulated the development of sustainable alternative energy sources. One approach is the development of artificial water splitting electrocatalysts based on solid state materials, such as utilizing solar energy generated by perovskites for efficient O2 and H2 production from water. Perovskite solar cells is a growing field of efficient and affordable photovoltaic devises. Current systems use expensive organic poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) for hole transporting layers when constructed in the nip configuration. NiO is potentially an efficient alternative to PEDOT:PSS but cannot be used directly because its solubility in various solvent is similar to perovskites. Previous work has shown that capping agents can be added to NiO during in situ synthesis. Addition of organic capping agents to NiO should improve its solubility in alternative organic solvents enabling deposition on perovskite surfaces. NiO coated perovskite inks are cheaper than the PEDOT:PSS materials currently used and are ideal for mass production of perovskite solar cells. In this study, we will demonstrate a process for adding capping agents to pre-synthesized NiO particles. Earlier capping agents included long chain carboxylic acids and xanthates. Herein, we evaluated the effect of chain length reduction on the conductivity of NiO materials. In addition, we will demonstrate using PXRD, IR, and SEM that the addition of these capping agents maintains the NiO crystallinity and conductivity.

Simultaneous bioelectricity generation from cost-effective MFC and water treatment using various wastewater samples

Worldwide, the requirement of electrical energy has increased with an increase in population. Thus, there is a need to develop an alternative source of sustainable energy, such as microbial fuel cell (MFC). MFC is a better option of energy generation and can provide a renewable resource which utilizes wastewater into power by the help of microorganisms. MFC is one of the advanced methods for treating wastewater and simultaneously producing current and voltage. Dual-chambered MFC was prepared using two plastic boxes (500 ml) by using wastewater as an anolyte. Different types of mediators are used in MFC including methylene blue, potassium ferricyanide, and EDTA to facilitate and higher the efficiency of electron transfer from the MFC to the electrode. Maximum OCV and current output of sample 1 (Budha Talab pond water) were 0.86 V and 75.1 mA and of sample 2 (Jaypee cement plant) were 1.42 V and 122 mA. The maximum current output of sample 3 (sugar industry, sewage waste, NIT canteen) was 1.3 V. Various physiochemical parameters such as dissolved oxygen (DO), biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were analyzed which affect the power output. The obtained result concluded that wastewater should be feed at a certain time interval to avoid the loss of substrate for organisms in the anodic chamber which lead to the death of themicroorganism. Among all, sugar industry wastewater has a high potential for power generation as their physiochemical results are suitable for better power output.

An earth-abundant, amorphous cobalt-iron-borate (Co-Fe-Bi) prepared on Ni foam as highly efficient and durable electrocatalysts for oxygen evolution

The rational designing of Earth-abundant, low-cost and efficient oxygen evolution reaction electrocatalysts is prerequisite to develop the alternative sustainable energy sources. In this work, we demonstrate the development of a highly efficient and durable electrocatalyst based on an amorphous Co-Fe-Bi directly grown on three-dimensional nickel foam via a facile solution approach. Co-Fe-Bi electrocatalysts on nickel foam exhibits an overpotential of ~307 mV to achieve the geometrical current density of 10 mA cm−2, a low Tafel slope of ~68.6 mV dec−1 and outstanding durability for 40 h at a mass loading of 1.2 mg cm−2, which is superior to those of borate-based electrocatalysts reported in the literature. This remarkable preliminary electrocatalytic performance in Co-Fe-Bi originates from the synergistic influence of unique binder-free ultra-thin nanosheets on the three dimensional porous structure, amorphous nature of multimetal-metalloid complex with highly abundant catalytically active sites and high conductivity of nickel foam. This work holds a great promise in the design and development of highly efficient and durable electrocatalysts at a large-scale based on an amorphous bimetallic borate nanosheets using a facile one-step solution process.

Carbon cloth/transition metals-based hybrids with controllable architectures for electrocatalytic hydrogen evolution - A review

Recently, the demand for energy consumption has been increasing exponentially due to the exhaustion of fossil fuels in the environment. This is the foremost technical challenge to the researchers to progress clean and alternative sustainable energy sources. Among various kinds of energy sources, an environment-friendly fuel, hydrogen is recognized as a favorable energy carrier to reduce the necessity on fossil fuels and protect the environment by reducing the discharge of greenhouse and other toxic gases. Thus, effective production and storage of hydrogen through a cost-effective and significant approach are the important factors of sustainable hydrogen production. Electrocatalytic water splitting is a favorable method for the hydrogen evolution reaction (HER), which requires an efficient and strong electrocatalyst to accelerate the kinetics of HER. To date, the well-developed electrocatalysts for HER activity are Pt-group metals, but, these electrocatalysts are inadequate and more expensive. In recent years, significant improvement has been achieved in the development of carbon cloth-based HER electrocatalysts as a replacement to Pt-based catalysts for hydrogen production in acidic medium. In this review, we mainly focused on the recent growth in the establishment of carbon-cloth functionalized transition metal (Fe-, Co-, Ni-, Mo-, and W-) based electrocatalysts towards the enhancement of HER activity. Depending on the results, we believed that the transition metal-based electrocatalysts have been appearing as fascinating and future alternative catalysts due to their morphology improvements, synergistic effects, a significant enhancement in the production of active sites, charge transfer efficiency, and superior HER activity with great durability. In addition, we outline the remarkable challenges and future prospects in this inspiring field.

The Development of Redox-Active Helical Polypeptides for Battery Application

This work seeks to develop polypeptide nanocomposites containing redox-active moieties as cathode and anode components to circumvent the drawbacks of conventional lithium ion batteries, e.g., use of scarce resources, high carbon emissions, and high-cost recycling. Polymer frameworks carrying 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) and viologen moieties are recognized as viable materials for next-generation battery cathodes and anodes, respectively, due to their stabilities and redox processes. Anticipating that the secondary structures adopted by polypeptides will provide opportunities to control the placement of radicals in three-dimensional space by tuning the distribution of radicals along polymer backbones, polypeptides containing TEMPO and viologen were designed for utilization in electrodes. This presentation will highlight the synthetic processes, followed by investigation of the physical and electrochemical properties of the materials, and their secondary structures, by utilizing a variety of thermal, spectroscopic, and imaging techniques. It is anticipated that the synthetic development of radical polypeptide nanocomposites will address needs in the advancement of high-performance and sustainable alternative energy sources (e.g., supercapacitors, and biosensors) towards a greener and more sustainable world, which is facing a never-ending demand for energy technologies. Figure 1

Evaluating Forest Biomass Recovery in South Central Alabama Pine Plantations

AbstractImproved use of forest biomass has been presented as a viable option to satisfy a portion of the demand for sustainable alternative sources of energy. Yet, there are considerable gaps in our understanding related to the efficiencies of current state-of-the-art forest biomass recovery systems. Southern pine plantation biomass stands typically exhibit higher stand densities and smaller-diameter trees than conventional stands, which, in turn, may result in reduced recovery efficiencies. In this study, the impact of new harvest systems for biomass recovery was investigated in typical southern pine plantation biomass harvests. Specifically, spatial and temporal effects on residue distribution were examined following biomass harvest of 14- and 24-year-old loblolly pine plantations. Preharvest total standing biomass for the younger site at 90 t ac–1 (220 t hectare–1) was half that of the older site at 160 t ac–1 (390 t hectare–1). Although the analysis detected no significant temporal effects on residue distributions, the preharvest condition exhibited 100 percent ground cover, whereas postharvest conditions had nearly 20 percent of the area designated as bare. Two of the five residue classifications, light debris and litter-herbaceous, were found to have a significantly higher incidence of occurrence than the other residue classifications on the sites based on a multinomial regression. In general, we found recovery efficiencies for both sites of 80 percent or greater for both methods of determination, by destructive sampling and based on load tickets.

Environmental Effects of Petroleum Leaks Around Diyarbakir City (SE Anatolia of Turkey) and Its Environment

Petroleum, a type of fossil fuels, is made up of the words “petra” meaning stone in Latin and “oleum” meaning oil (Petra oleum = Petrol) and it is Petroleum is English. Due to the growing population in the world, dependence on oil continues despite the search for clean and sustainable alternative energy sources. Just like all fossil-based energy sources, it is a fact that the use of oil causes air pollution, indirectly pollution of land and water resources, and the most important problem of today, global warming. Oil spills are one of the causes of this pollution. Natural and artificial oil spills cause oil pollution and cause damage that is difficult to recycle in the environment. Petroleum poses a serious risk to water resources in the pre-use phase. In this study; it will be investigated whether there is any pollutant effect on the fresh water resources in the pre-use stages of oil exploration, production, transportation, processing and storage. As a research area, Diyarbakır Province, which is located in the north of the Upper Mesopotamian Basin, where all phases (systems) before use such as exploration, production, transmission, storage and treatment (refining) are found altogether. Almost all of the oil production in Turkey is provided from the South-eastern Anatolia Region. With daily crude oil production, Diyarbakır is the second largest producer of crude oil after Batman. In Diyarbakır province there are 42 Oil Fields operated by various oil producers and over 260 Oil Wells are located in these fields. In the scope of this study; In Diyarbakır province, active or inactive oil fields and their locations will be determined and their impact areas will be determined. Underground and surface water resources (existing wells, streams and natural and artificial lakes) being in the impact area will be identified and their locations will be processed on the map. Samples will be taken from the water sources along with the field study. Physical and chemical analyzes of the samples will be performed. In this context, it will be investigated whether there are any petroleum components in the water resources and in what stage and where the pollution before the consumption occurs.

Heat generation in biofuel tractor diesel engines

While legal restrictions on the use of fossil fuels are being applied to conserve natural resources, mixed spirit fuels, vegetable oils and their esters are attracting increasing attention as promising alternative sustainable energy sources for tractors and agricultural machinery. The paper substantiates the need for the use of biofuels in tractor diesel engines. It is shown that the choice for diesel alternative biofuel with a perspective should be carried out in accordance with the design features of the engine and during its primary tests. In the paper we investigate such environmentally friendly energy sources such as methanol, ethanol and methyl ester of rapeseed oil (MЕRО). Methanol, ethanol and MЕRО have the potential to lead to some solutions to environmental problems, as there are abundant resources for their production and these sources of energy are characterized by relatively low emissions of harmful substances during combustion. The ways of bioethanol production from various raw materials and the process of rapeseed oil methanolysis are considered. It is shown that agricultural enterprises that consume mainly petroleum products as fuel are now quite capable of producing at least environmentally friendly renewable biofuels for their tractors. Experimental studies of tractor diesel engines on biofuels of the following compositions were carried out: alcohol-fuel emulsion (AFE, alcohol (methanol, ethanol) - 25 %, detergent-dispersing additive succinimide C-5A - 0,5 %, water - 7,0 %, diesel fuel - 67,5 %); methanol (88,0 %) and MЕRО (12,0 %). Based on the studies of the thermal performance of tractor diesel engines running on biofuel, the nature of the influence of their work on the characteristics of heat dissipation and defined their numeric values.

The role of energy-scape elements in creating sustainable economic project in Egyptian parks

Abstract Electricity, have recently became the backbone of all industrial, information and service sectors. Moreover, the global energy consumption has doubled in the last century, a global demand to use alternative sources of sustainable energy has increased. The current work focuses on a major concern in developing countries such as Egypt, where its neighborhoods and cities are facing shortage in their basic needs of electricity supply, which effect the economic state and the urban developments of theses countries and relaying on fossil fuel is not a solution. This research introduce a solution that will provide the electricity demand for the urban projects and became self-sustain projects by using the wide spread of landscape elements in the major projects and the overall urban context to generate efferent and clean energy using renewable energy (RE) devices. Integrating RE devices with landscape elements will create new elements called 'Energy-scape' elements. The results shows that using three Energy-scape elements can satisfy the energy consumption of the park services while using four Energy-scape elements will produce more than the energy consumed in this urban project with Zero carbon emissions.

Facile synthesis of Tungsten Phosphide/Ketjen Black Hybrid Electrocatalyst for Hydrogen Production

Hydrogen is considered a clean and sustainable alternative energy source in future, and transition metal phosphides as substitutes for Pt-based electrocatalysts for the hydrogen evolution reaction (HER) have received widespread attention. However, exploring a facile way to synthesize efficient catalysts is still a challenge. In this work, we found a simple and safe way to obtain tungsten phosphide (WP) and the influence of synthesis temperature was also investigated. Moreover, with the modification of Ketjen Black, WP/KB heterostructures were gained, which showed an excellent HER performance in both acidic and alkaline solutions with Tafel slopes of 60 mV dec−1 and 66 mV dec−1, respectively. Furthermore, a possible improvement mechanism was also discussed.

An industrial perspective on membrane distillation processes

AbstractProcess intensification has led to significant developments in both distillation and membrane technology. Membrane distillation (MD) is an emerging technology for fluid separations that are typically performed by conventional separation processes, such as distillation or reverse osmosis (e.g. water desalination, or water removal). Compared with other membrane technologies, the driving force in MD is the difference in vapor pressure across the hydrophobic membrane, rather than the total pressure. MD can be a cost effective separation process, especially when more sustainable alternative sources of energy (e.g. geothermal and solar) or waste heat sources are used. Many review papers on MD are available in the open literature, but most of them focus on the membrane characteristics (e.g. material aspects).This industrial perspective paper assesses the MD technology and reports on relevant issues by offering a concise overview of MD technology, addressing different MD configurations, current major applications, operating parameters and their effect on the MD process, commercially available membranes, as well as cost estimations to determine the feasibility of MD processes. While successfully applied in desalination and a few other niche applications, MD has failed to make a strong industrial impact in other areas still dominated by distillation. A key message is that membrane distillation is still a growing technology for separation and purification processes, but it needs further exploration and optimization to become a mature technology applicable to more industrial processes in the chemical process industry. © 2018 Society of Chemical Industry

Biofuels: Production of fungal-mediated ligninolytic enzymes and the modes of bioprocesses utilizing agro-based residues

Abstract The depletion of fossil fuels and rise in their global energy consumption and demand have had a major impact on the stability of the ecosystem and highlighted the need for efficient, sustainable, and renewable alternative sources of energy. Lignocellulosic biomass-based biofuels are highly advantageous due to their enormous supply in nature. Enzymatic bioconversion of lignocellulose polysaccharides into monomeric sugars has a higher efficiency than traditional chemical modes of action. Fungal-mediated ligninolytic enzymes offer even greater advantages in the bioconversion of lignocelluloses into simple sugars due to their thermostability, activity across a wide range of pH values, high specificity, and minimal by-products. This review, based on recent developments in the field of fungal-derived ligninolytic enzymes, discusses their mechanisms of action along with their production and the modes of bioprocesses involved as well as different techniques, such as heterologous gene expression, mutagenesis, and co-culturing, that enhance production and improve catalytic and stability properties.

Structural evolution of a Ge-substituted SnSe thermoelectric material with low thermal conductivity

Thermoelectric materials are expected to become new alternative sources of sustainable energy. Among them, the SnSe intermetallic alloy has been described as an excellent thermoelectric compound, characterized by an extremely low thermal conductivity with maximum performance at the onset of a structural phase transition at 800 K. Recently, novel SnSe derivatives with Ge substitution have been synthesized by a direct arc-melting technique. This produces nanostructured polycrystalline samples that exhibit a record high Seebeck coefficient, anticipating an excellent performance above room temperature. Here, the structural phase transition from a GeS-type structure (space groupPnma) to a TlI-type structure (space groupCmcm) is investigatedin situ vianeutron powder diffraction (NPD) in the temperature range 298–853 K for the selected composition Sn0.8Ge0.2Se. This transition takes place at 803 K, as shown by differential scanning calorimetry. The analysis from the NPD data shows a non-monotonic behaviour of the anisotropic displacement parameters upon entering the domain of theCmcmstructure. The energies of the atomic vibrations have been quantitatively analysed by fitting the temperature-dependent mean-square displacements to Einstein oscillators. The thermal conductivity of Sn0.8Ge0.2Se is as low as 0.35 W m−1 K−1at 773 K, which mostly represents the lattice thermal contribution.

Ag@TiO2 Nanowires-Loaded Dye-Sensitized Solar Cells and Their Effect on the Various Performance Parameters of DSSCs

In the search for sustainable alternative energy sources the dye-sensitized solar cell (DSSC) has proven a viable contender in photovoltaics with core advantages of facile and low-cost fabrication; and record cell power conversion efficiency (PCE) between 11–14%. This is competitively low; compared to that of the more common Si-based cells of 14–26%. Plasmonic DSSCs, with the potential of highly concentrating optical energy in cells from the localized surface plasmon resonance effect, were predicted to attain very high PCEs. However, the record plasmonic DSSC PCE is only 10.8%, attributed to, mainly, the secondary effects of plasmonic nanostructures not well understood yet. This study employed Ag@TiO2 plasmonic nanowires (PNWs), a systematic approach, wide-range PNW loadings and extended characterization to study their effects on the performance of DSSCs. They enhanced PCE from 4.63% to 5.03% from a balance of the negative and positive effects of the PNWs; most uniquely via efficient charge transport. The PNWs exhibited electron-sink effect causing upward shift of the TiO2 Fermi level with poor charge injection efficiency, at high concentrations. They improved charge collection and resistance against recombination. These results will serve as valuable guide in the field of plasmonic DSSCs and related fields.

BIOFUELS AS PROMISING FUELS

The use of fossil fuels results in global warming and pollution. In comparison with fossil fuels biofuels represent an eco-friendly, biodegradable, sustainable, cost-competitive and promising alternative energy source. They contain high energy content and do not contribute to greenhouse effect. Therefore, using cheap or renewable resources as the feedstock for biofuels production has a great potential in terms of a major contribution to future energy supply. The production and use of biofuels is already well established and a further promotion of these fuels such as lipid biofuels (bioethanol, pure plant oils and biodiesel) and gas biofuels (biomethane, biohydrogen) mainly depends on non-technical issues, such as policies and cost–effectiveness. Biofuels will definitely stay for the foreseeable future and still can continue to provide the earth and the human population with a relatively clean source of energy with several benefits such as economic benefits of providing employment and health benefits of reduced carbon emissions, leading to cleaner air. With increasing sophistication of technology and intense research and development done, one can safely infer that biofuel will become more appealing and applicable for use on a globally commercial level. As such, biofuel is acknowledged as the Earth’s future energy source. Until a newer and cleaner energy source is discovered, scientists will definitely persist in researching and enhancing biofuels to make them more cost-effective, while still being environmentally friendly.

Biodiesel production process optimization from Spirulina maxima microalgae and performance investigation in a diesel engine

Biodiesel is a renewable, easily biodegradable, eco-friendly and sustainable alternative energy source. In this investigation, crude oil was extracted from Spirulina maxima microalgae through biochemical conversion method with the help of soxhlet apparatus. Biodiesel production process parameters were optimized through base transesterification. Maximum biodiesel yield achieved was 87.75 % at optimal reaction condition after transesterification, when methanol to oil ratio was 6:1, catalyst loading was 1 % KOH (wt.%), temperature was 65 °C, and stirring speed was 600 rpm for a reaction time of 70 minutes. All the physicochemical properties of the produced biodiesel were determined and compared with the ASTM D6751 specification. Finally, performance and emission of an unmodified diesel engine was evaluated with 20 % and 40 % (v/v) biodiesel blends and compared the results with ordinary Diesel fuel (DF). Using biodiesel blends improves Hydrocarbon (HC) emission by 10-15 % and Carbon monoxide (CO) emission by 9.3-13.9 %. However, Brake specific fuel consumption (BSFC), Oxides of nitrogen (NOX), Carbon dioxide (CO2) and smoke opacity were found to be slightly higher for biodiesel blends, and Brake thermal efficiency (BTE) was found slightly lower than DF. Thus, Spirulina maxima serves as a potential feedstock for biodiesel production and prospective fuel in diesel engine application.

Integrating biomass quality variability in stochastic supply chain modeling and optimization for large-scale biofuel production

The production of biofuels using second-generation feedstocks has been recognized as an important alternative source of sustainable energy and its demand is expected to increase due to regulations such as the Renewable Fuel Standard. However, the pathway to biofuel industry maturity faces unique, unaddressed challenges.To address this challenges, this paper presents an optimization model which quantifies and controls the impact of biomass quality variability on supply chain related decisions and technology selection. We propose a two-stage stochastic programming model and associated efficient solution procedures for solving large-scale problems to (1) better represent the random nature of the biomass quality (defined by moisture and ash contents) in supply chain modeling, and (2) assess the impact of these uncertainties on the supply chain design and planning.The proposed model is then applied to a case study in the state of Tennessee. Results show that high moisture and ash contents negatively impact the unit delivery cost since poor biomass quality requires the addition of quality control activities. Experimental results indicate that supply chain cost could increase as much as 27%–31% when biomass quality is poor. We assess the impact of the biomass quality on the topological supply chain. Our case study indicates that biomass quality impacts supply chain costs; thus, it is important to consider the impact of biomass quality in supply chain design and management decisions.

Investigating solar energy potential in tropical urban environment: A case study of Dar es Salaam, Tanzania

Solar energy is considered to be an alternative sustainable energy source in the urban environment. The potential of using solar energy in urban areas is highly dependent on urban morphology which affects the level of solar irradiance received by individual buildings. Many studies focus on solar energy potential of building form in urban areas but relatively few studies examine how urban morphology affects solar energy potential of urban neighbourhoods. It leads to inefficient design of neighbourhoods in terms of solar energy potential. The present study investigates the potential of exploiting solar energy in Dar es Salaam, Tanzania by using numerical modelling of solar irradiance on building roofs and façades. It is shown that there is substantial solar irradiance received by building roofs in all four study neighbourhoods and urban morphology has considerable effects on annual solar irradiance. Solar irradiance of different orientations of tilted roofs and façades is subject to seasonality of the solar azimuth angle. It is suggested that such abundant solar energy sources would provide solutions to accommodate the increasing energy demand and to improve living quality in urban areas due to the rapid urbanization of the city.

Energy harvesting from pavement via polyvinylidene fluoride: hybrid piezo-pyroelectric effects

In the USA, there are over 4 million miles (6 million km) of roadways and more than 250 million registered vehicles. Energy lost in the pavement system due to traffic-induced vibration and deformation is enormous. If effectively harvested, such energy can serve as an alternative sustainable energy source that can be easily integrated into the transportation system. It is well known that most piezoelectric materials are also pyroelectric materials, which convert temperature change into electricity. However, the potential of polyvinylidene fluoride (PVDF) as a hybrid piezo-pyroelectric energy harvester has been seldom studied. The uniqueness of this study lies in that the electrical responses of PVDF under coupled mechanical and thermal stimulations are investigated. Through a series of well controlled experiments, it is found that there exists an interesting coupling phenomenon between piezoelectric and pyroelectric effects of PVDF: the voltage generated by simultaneous mechanical and thermal stimulations is the algebraic sum of voltages generated by separate stimulations. This means that there is neither strengthening nor weakening coupling effect when the piezoelectric and pyroelectric phenomena are coupled. This also makes the modeling process of the hybrid piezoelectric and pyroelectric effect straightforward. An estimation of power generation through piezoelectric and pyroelectric effect is conducted, and the overall effects of temperature on hybrid piezo-pyroelectric energy harvesting are discussed.