Showing papers on "Energy source published in 2010"
IBM1
TL;DR: In this article, the authors summarized the promise and challenges facing development of practical Li−air batteries and the current understanding of its chemistry, and showed that the fundamental battery chemistry during discharge is the electrochemical oxidation of lithium metal at the anode and reduction of oxygen from air at the cathode.
Abstract: The lithium−air system captured worldwide attention in 2009 as a possible battery for electric vehicle propulsion applications. If successfully developed, this battery could provide an energy source for electric vehicles rivaling that of gasoline in terms of usable energy density. However, there are numerous scientific and technical challenges that must be overcome if this alluring promise is to turn into reality. The fundamental battery chemistry during discharge is thought to be the electrochemical oxidation of lithium metal at the anode and reduction of oxygen from air at the cathode. With aprotic electrolytes, as used in Li-ion batteries, there is some evidence that the process can be reversed by applying an external potential, i.e., that such a battery can be electrically recharged. This paper summarizes the authors’ view of the promise and challenges facing development of practical Li−air batteries and the current understanding of its chemistry. However, it must be appreciated that this perspective ...
2,308 citations
TL;DR: The engineering of Escherichia coli is demonstrated to produce structurally tailored fatty esters (biodiesel), fatty alcohols, and waxes directly from simple sugars, a step towards producing these compounds directly from hemicellulose, a major component of plant-derived biomass.
Abstract: Increasing energy costs and environmental concerns have emphasized the need to produce sustainable renewable fuels and chemicals. Major efforts to this end are focused on the microbial production of high-energy fuels by cost-effective 'consolidated bioprocesses'. Fatty acids are composed of long alkyl chains and represent nature's 'petroleum', being a primary metabolite used by cells for both chemical and energy storage functions. These energy-rich molecules are today isolated from plant and animal oils for a diverse set of products ranging from fuels to oleochemicals. A more scalable, controllable and economic route to this important class of chemicals would be through the microbial conversion of renewable feedstocks, such as biomass-derived carbohydrates. Here we demonstrate the engineering of Escherichia coli to produce structurally tailored fatty esters (biodiesel), fatty alcohols, and waxes directly from simple sugars. Furthermore, we show engineering of the biodiesel-producing cells to express hemicellulases, a step towards producing these compounds directly from hemicellulose, a major component of plant-derived biomass.
1,344 citations
TL;DR: In this article, the authors highlight recent efforts and opportunities in the heterogeneous electrochemical conversion of carbon dioxide to help address the global issues of climate change and sustainable energy production, and highlight the potential of electrochemical reduction of CO2 to produce a variety of organic compounds such as formic acid, carbon monoxide, methane, and ethylene with high current efficiency.
Abstract: This Perspective highlights recent efforts and opportunities in the heterogeneous electrochemical conversion of carbon dioxide to help address the global issues of climate change and sustainable energy production. Recent research has shown that the electrochemical reduction of CO2 can produce a variety of organic compounds such as formic acid, carbon monoxide, methane, and ethylene with high current efficiency. These products can be used as feedstocks for chemical synthesis or converted into hydrocarbon fuels. This process is of interest (i) for the recycling of CO2 as an energy carrier, thereby reducing its accumulation in the atmosphere, (ii) for the production of renewable hydrocarbon fuels from CO2, water, and renewable electricity for use as transportation fuels, and (iii) as a convenient means of storing electrical energy in chemical form to level the electrical output from intermittent energy sources such as wind and solar. Accomplishments to date in this field of study have been encouraging, yet s...
1,161 citations
04 Nov 2010
TL;DR: This paper analytically model the subscribers' preferences and their energy consumption patterns in form of carefully selected utility functions based on concepts from microeconomics and proposes a distributed algorithm which automatically manages the interactions among the ECC units at the smart meters and the energy provider.
Abstract: In this paper, we consider a smart power infrastructure, where several subscribers share a common energy source. Each subscriber is equipped with an energy consumption controller (ECC) unit as part of its smart meter. Each smart meter is connected to not only the power grid but also a communication infrastructure such as a local area network. This allows two-way communication among smart meters. Considering the importance of energy pricing as an essential tool to develop efficient demand side management strategies, we propose a novel real-time pricing algorithm for the future smart grid. We focus on the interactions between the smart meters and the energy provider through the exchange of control messages which contain subscribers' energy consumption and the real-time price information. First, we analytically model the subscribers' preferences and their energy consumption patterns in form of carefully selected utility functions based on concepts from microeconomics. Second, we propose a distributed algorithm which automatically manages the interactions among the ECC units at the smart meters and the energy provider. The algorithm finds the optimal energy consumption levels for each subscriber to maximize the aggregate utility of all subscribers in the system in a fair and efficient fashion. Finally, we show that the energy provider can encourage some desirable consumption patterns among the subscribers by means of the proposed real-time pricing interactions. Simulation results confirm that the proposed distributed algorithm can potentially benefit both subscribers and the energy provider.
995 citations
TL;DR: In this article, the hydrogen storage in metal hydrides with particular interest in Mg as it has potential to become one of the most promising storage materials, and the possibility of commercialization of Mg based alloys has been discussed.
922 citations
TL;DR: The results presented here suggest that microbiological catalysts may be a robust alternative, and when coupled with photovoltaics, current-driven microbial carbon dioxide reduction represents a new form of photosynthesis that might convert solar energy to organic products more effectively than traditional biomass-based strategies.
Abstract: The possibility of providing the acetogenic microorganism Sporomusa ovata with electrons delivered directly to the cells with a graphite electrode for the reduction of carbon dioxide to organic compounds was investigated. Biofilms of S. ovata growing on graphite cathode surfaces consumed electrons with the reduction of carbon dioxide to acetate and small amounts of 2-oxobutyrate. Electrons appearing in these products accounted for over 85% of the electrons consumed. These results demonstrate that microbial production of multicarbon organic compounds from carbon dioxide and water with electricity as the energy source is feasible.
853 citations
TL;DR: It is concluded that AMPK acts as the primordial trigger for fasting- and exercise-induced adaptations in skeletal muscle and that activation of SIRT1 and its downstream signaling pathways are improperly triggered in AMPK-deficient states.
769 citations
TL;DR: Recent advances in new types of electrodes, a better understanding of the impact of membranes and separators on performance of these systems, and results from several new pilot-scale tests are all good indicators that commercialization of the technology could be possible within a few years.
Abstract: Scientific research has advanced on different microbial fuel cell (MFC) technologies in the laboratory at an amazing pace, with power densities having reached over 1 kW/m3 (reactor volume) and to 6.9 W/m2 (anode area) under optimal conditions. The main challenge is to bring these technologies out of the laboratory and engineer practical systems for bioenergy production at larger scales. Recent advances in new types of electrodes, a better understanding of the impact of membranes and separators on performance of these systems, and results from several new pilot-scale tests are all good indicators that commercialization of the technology could be possible within a few years. Some of the newest advances and future challenges are reviewed here with respect to practical applications of these MFCs for renewable energy production and other applications.
767 citations
TL;DR: This paper examined the causal relationship between CO2 emissions, nuclear energy consumption, nuclear consumption, renewable energy consumption and economic growth for a group of 19 developed and developing countries for the period 1984-2007 using a panel error correction model.
759 citations
TL;DR: In this article, the authors investigate the algae production technologies such as open, closed and hybrid systems, production costs, and algal energy conversions, in order to investigate the potential of algae as a promising source of biodiesel.
686 citations
TL;DR: In this paper, a pilot scale fluidized bed reactor was used to produce bio-oil and bio-char from corn cobs and corn stover (stalks, leaves and husks) by fast pyrolysis.
Abstract: Bio-oil and bio-char were produced from corn cobs and corn stover (stalks, leaves and husks) by fast pyrolysis using a pilot scale fluidized bed reactor. Yields of 60% (mass/mass) bio-oil (high heating values are ∼20 MJ kg −1 , and densities >1.0 Mg m −3 ) were realized from both corn cobs and from corn stover. The high energy density of bio-oil, ∼20–32 times on a per unit volume basis over the raw corn residues, offers potentially significant savings in transportation costs particularly for a distributed “farm scale” bio-refinery system. Bio-char yield was 18.9% and 17.0% (mass/mass) from corn cobs and corn stover, respectively. Deploying the bio-char co-product, which contains most of the nutrient minerals from the corn residues, as well as a significant amount of carbon, to the land can enhance soil quality, sequester carbon, and alleviate environmental problems associated with removal of crop residues from fields.
TL;DR: In this paper, a meshed, multi-terminal VSC HVDC is proposed as the best suitable technology for a supergrid, and the potential and need for such a grid is described.
Abstract: For many, the supergrid is seen as the solution that allows the massive integration of renewable energy sources in the European power system It connects different remote energy sources to the existing grid while offering additional control It offers balancing through geographic spread and allows a more diversified energy portfolio In the meanwhile it increases the security of supply However, technical limitations exist, and it is not yet possible to construct such a supergrid Several outstanding issues need to be solved This paper first describes the potential and need for a supergrid The paper focuses on a meshed, multi-terminal VSC HVDC, and it is explained why this relatively new technology is believed to be the best suitable one for such a grid The different difficulties or challenges that still exist are addressed Not only the remaining technical limitations are addressed, but also the techno-economic, control and operational issues are discussed, as well as some regulatory obstacles
TL;DR: The major challenges in expanding WTE incineration in China are discussed, namely, high capital and operational costs, equipment corrosion, air pollutant emissions, and fly ash disposal.
TL;DR: In this article, the authors considered the best option and has the largest potential, which meets energy requirements and could insure fuel supply in the future, and showed that biomass gasification offers the earliest and most economical route for the production of renewable hydrogen.
TL;DR: A number of gas hydrates are known to form at moderate pressure, and nearly ten structures in the pressure range above 100MPa as discussed by the authors. But, these structures are not stable at high temperatures.
TL;DR: Plant growth-promoting rhizobacteria (PGPR) are potential agents for the biological control of plant pathogens and a biocontrol strain should be able to protect the host plant from pathogens and fulfill the requirement for strong colonization.
Abstract: The rhizosphere is the soil-plant root interphase and in practice consists of the soil adhering to the root besides the loose soil surrounding it. Plant growth-promoting rhizobacteria (PGPR) are potential agents for the biological control of plant pathogens. A biocontrol strain should be able to protect the host plant from pathogens and fulfill the requirement for strong colonization. Numerous compounds that are toxic to pathogens, such as HCN, phenazines, pyrrolnitrin, and pyoluteorin as well as, other enzymes, antibiotics, metabolites and phytohormones are the means by which PGPR act, just as quorum sensing and chemotaxis which are vital for rhizosphere competence and colonization. The presence of root exudates has a pronounced effect on the rhizosphere where they serve as an energy source, promoting growth and influencing the root system for the rhizobacteria. In certain instances they have products that inhibit the growth of soil-borne pathogens to the advantage of the plant root. A major source of concern is reproducibility in the field due to the complex interaction between the plant (plant species), microbe and the environment (soil fertility and moisture, day length, light intensity, length of growing season, and temperature). This review listed most of the documented PGPR genera and discussed their exploitation.
TL;DR: RTILs present a highly versatile and tunable platform for the development of new processes and materials aimed at the capture of CO(2) from power plant flue gas and in natural gas sweetening and new imidazolium-based polymer architectures and thermotropic and lyotropic liquid crystals as highly tailorable materials based on and capable of interacting with RTILs are developed.
Abstract: Clean energy production has become one of the most prominent global issues of the early 21st century, prompting social, economic, and scientific debates regarding energy usage, energy sources, and sustainable energy strategies. The reduction of greenhouse gas emissions, specifically carbon dioxide (CO2), figures prominently in the discussions on the future of global energy policy. Billions of tons of annual CO2 emissions are the direct result of fossil fuel combustion to generate electricity. Producing clean energy from abundant sources such as coal will require a massive infrastructure and highly efficient capture technologies to curb CO2 emissions. Current technologies for CO2 removal from other gases, such as those used in natural gas sweetening, are also capable of capturing CO2 from power plant emissions. Aqueous amine processes are found in the vast majority of natural gas sweetening operations in the United States. However, conventional aqueous amine processes are highly energy intensive; their imp...
TL;DR: The findings reveal that m TORC1 is a key regulator of PPARα function and hepatic ketogenesis and suggest a role for mTORC1 activity in promoting the ageing of the liver.
Abstract: The multi-component mechanistic target of rapamycin complex 1 (mTORC1) kinase is the central node of a mammalian pathway that coordinates cell growth with the availability of nutrients, energy and growth factors. Progress has been made in the identification of mTORC1 pathway components and in understanding their functions in cells, but there is relatively little known about the role of the pathway in vivo. Specifically, we have little knowledge regarding the role mTOCR1 has in liver physiology. In fasted animals, the liver performs numerous functions that maintain whole-body homeostasis, including the production of ketone bodies for peripheral tissues to use as energy sources. Here we show that mTORC1 controls ketogenesis in mice in response to fasting. We find that liver-specific loss of TSC1 (tuberous sclerosis 1), an mTORC1 inhibitor, leads to a fasting-resistant increase in liver size, and to a pronounced defect in ketone body production and ketogenic gene expression on fasting. The loss of raptor (regulatory associated protein of mTOR, complex 1) an essential mTORC1 component, has the opposite effects. In addition, we find that the inhibition of mTORC1 is required for the fasting-induced activation of PPARα (peroxisome proliferator activated receptor α), the master transcriptional activator of ketogenic genes, and that suppression of NCoR1 (nuclear receptor co-repressor 1), a co-repressor of PPARα, reactivates ketogenesis in cells and livers with hyperactive mTORC1 signalling. Like livers with activated mTORC1, livers from aged mice have a defect in ketogenesis, which correlates with an increase in mTORC1 signalling. Moreover, we show that the suppressive effects of mTORC1 activation and ageing on PPARα activity and ketone production are not additive, and that mTORC1 inhibition is sufficient to prevent the ageing-induced defect in ketogenesis. Thus, our findings reveal that mTORC1 is a key regulator of PPARα function and hepatic ketogenesis and suggest a role for mTORC1 activity in promoting the ageing of the liver.
22 Mar 2010
TL;DR: Simulation results confirm that the proposed distributed algorithm significantly reduces the peak-to-average-ratio (PAR) in load demand and the total cost in the system.
Abstract: In this paper, we consider deployment of energy consumption scheduling (ECS) devices in smart meters for autonomous demand side management within a neighborhood, where several buildings share an energy source. The ECS devices are assumed to be built inside smart meters and to be connected to not only the power grid, but also to a local area network which is essential for handling two-way communications in a smart grid infrastructure. They interact automatically by running a distributed algorithm to find the optimal energy consumption schedule for each subscriber, with an aim at reducing the total energy cost as well as the peak-to-average-ratio (PAR) in load demand in the system. Incentives are also provided for the subscribers to actually use the ECS devices via a novel pricing model, derived from a game-theoretic analysis. Simulation results confirm that our proposed distributed algorithm significantly reduces the PAR and the total cost in the system.
TL;DR: Denitrifying bioreactors are an approach where solid carbon substrates are added into the flow path of contaminated water as mentioned in this paper, which act as a C and energy source to support denitrification.
TL;DR: DNA sequences of cellulase and associated genes, as well as physiological and morphological information about the digestive systems of cellulases-producing insects, may allow the efficient use of cellulosic biomass as a sustainable energy source.
Abstract: Despite the presence of many carbohydrolytic activities in insects, their cellulolytic mechanisms are poorly understood. Whereas cellulase genes are absent from the genomes of Drosophila melanogaster or Bombyx mori, other insects such as termites produce their own cellulases. Recent studies using molecular biological techniques have brought new insights into the mechanisms by which the insects and their microbial symbionts digest cellulose in the small intestine. DNA sequences of cellulase and associated genes, as well as physiological and morphological information about the digestive systems of cellulase-producing insects, may allow the efficient use of cellulosic biomass as a sustainable energy source.
TL;DR: In this article, the authors argue that German renewable energy policy, and in particular the adopted feed-in tariff scheme, has failed to harness the market incentives needed to ensure a viable and cost-effective introduction of renewable energies into the country's energy portfolio.
TL;DR: The scheduling problem of building energy supplies is considered with the practical background of a low energy building and testing results show that significant energy cost savings can be achieved through integrated scheduling and control of various building energy supply sources.
Abstract: Recent research shows that 20%-30% of building energy consumption can be saved through optimized operation and management without changing the building structure and the hardware configuration of the energy supply system. Therefore, there is a huge potential for building energy savings through efficient operation. Microgrid technology provides an opportunity and a desirable infrastructure for improving the efficiency of energy consumption in buildings. The key to improve building energy efficiency in operation is to coordinate and optimize the operation of various energy sources and loads. In this paper, the scheduling problem of building energy supplies is considered with the practical background of a low energy building. The objective function is to minimize the overall cost of electricity and natural gas for a building operation over a time horizon while satisfying the energy balance and complicated operating constraints of individual energy supply equipment and devices. The uncertainties are captured and their impact is analyzed by the scenario tree method. Numerical testing is performed with the data of the pilot low energy building. The testing results show that significant energy cost savings can be achieved through integrated scheduling and control of various building energy supply sources. It is very important to fully utilize solar energy and optimize the operation of electrical storage. It is also shown that precooling is a simple way to achieve energy savings.
TL;DR: In this paper, the authors proposed a methodology for allocating an ESS in a distribution system with a high penetration of wind energy, aiming to maximize the benefits for both the DG owner and the utility by sizing the ESS to accommodate all amounts of spilled wind energy and by then allocating it within the system in order to minimize the annual cost of the electricity.
Abstract: Environmental concerns and fuel cost uncertainties associated with the use of conventional energy sources have resulted in rapid growth in the amount of wind energy connected to distribution grids. However, based on Ontario's standard offer program (SOP), the utility has the right to curtail (spill) wind energy in order to avoid any violation of the system constraints. This means that any increase in wind energy production over a specific limit might be met with an increase in the wind energy curtailed. In spite of their cost, energy storage systems (ESSs) are considered to be a viable solution to this problem. This paper proposes a methodology for allocating an ESS in a distribution system with a high penetration of wind energy. The ultimate goal is to maximize the benefits for both the DG owner and the utility by sizing the ESS to accommodate all amounts of spilled wind energy and by then allocating it within the system in order to minimize the annual cost of the electricity. In addition, a cost/benefit analysis has been conducted in order to verify the feasibility of installing an ESS from the perspective of both the utility and the DG owner.
TL;DR: Everyone seems to agree that shale gas "provides the potential to transform North America's energy landscape," but every link in the chain between the newly abundant domestic energy source and its transformative impact is still shrouded in uncertainty.
Abstract: Engineering ingenuity is unlocking a vast storehouse of natural gas buried beneath American soil from Texas to New England. The sudden great promise of clean, homegrown shale gas has all kinds of people excited. National-security types see it as a replacement for foreign oil and gas, environmentalists as a replacement for dirty coal and even oil. And because it yields only 45% of the carbon dioxide emissions of coal, advocates of taming global warming see it as a temporary crutch while carbon-free energy sources are developed and deployed. Everyone seems to agree with a March study by IHS Cambridge Energy Research Associates that concluded that shale gas "provides the potential to transform North America9s energy landscape." The problem is that word "potential." Every link in the chain between the newly abundant domestic energy source and its transformative impact is still shrouded in uncertainty. And a rising tide of NUMBY—not under my backyard—that9s greeting shale gas in the Northeast could hobble the revolution (see sidebar).
TL;DR: Tidal energy has the potential to play a valuable part in a sustainable energy future and is an extremely predictable energy source, depending only on the gravitational pull of the moon and the sun and the centrifugal forces created by the rotation of the earth-moon system as discussed by the authors.
TL;DR: In this article, the principles of fast pyrolysis are discussed, and the main technologies reviewed (demo scale: fluid bed, rotating cone and vacuum pyrolynsis; pilot plant: ablative and twin screw pyrolyssis).
Abstract: While the intention of slow pyrolysis is to produce mainly charcoal, fast pyrolysis is meant to convert biomass to a maximum quantity of liquids (bio-oil). Both processes have in common that the biomass feedstock is densified to reduce storage space and transport costs. A comfortable, more stable and cleaner intermediate energy carrier is obtained, which is much more uniform and well defined. In this review, the principles of fast pyrolysis are discussed, and the main technologies reviewed (demo scale: fluid bed, rotating cone and vacuum pyrolysis; pilot plant: ablative and twin screw pyrolysis). Possible product applications are discussed in relation to the bio-oil properties. General mass and energy balance are provided as well, together with some remarks on the economics. Challenges for the coming years are (1) improvement of the reliability of pyrolysis reactors and processes; (2) the demonstration of the oil's utilization in boilers, engines and turbines; and (3) the development of technologies for the production of chemicals and biofuels from pyrolysis oils. One important conclusion in relation to biofuel production is that the type of oxygen functionalities (viz. as an alcohol, ketone, aldehyde, ether, or ester) in the oil should be controlled, rather then merely focusing on a reduction of just the oxygen content itself. Copyright © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd
TL;DR: The field is now in a position to develop a multiscale view of circadian systems, from the molecular level to the intact organism, and to apply this information for the development of new therapeutic strategies or for enhancing agricultural productivity in crops.
Abstract: An intrinsic clock enables an organism to anticipate environmental changes and use energy sources more efficiently, thereby conferring an adaptive advantage. Having an intrinsic clock to orchestrate rhythms is also important for human health. The use of systems biology approaches has advanced our understanding of mechanistic features of circadian oscillators over the past decade. The field is now in a position to develop a multiscale view of circadian systems, from the molecular level to the intact organism, and to apply this information for the development of new therapeutic strategies or for enhancing agricultural productivity in crops.
TL;DR: The first prototype installation of pressure retarded osmosis (PRO) was opened in Norway in late 2009 as mentioned in this paper, where water from a low salinity solution permeates through a membrane into a pressurized, highsalinity solution; power is obtained by depressurizing the permeate through a hydroturbine.
TL;DR: This research provides a method for preparing tandem DSSCs consisting of a TiO(2)-photosensitized anode and a photosensitized p-type SC as a cathode and demonstrates that ultrafast hole injection generally occurs between the sensitizer and the SC, but the resulting charge-separated state is short-lived and recombines quickly.
Abstract: Because solar energy is the most abundant renewable energy resource, the clear connection between human activity and global warming has strengthened the interest in photovoltaic science. Dye-sensitized solar cells (DSSCs) provide a promising low-cost technology for harnessing this energy source. Until recently, much of the research surrounding DSSCs had been focused on the sensitization of n-type semiconductors, such as titanium dioxide (Gratzel cells). In an n-type dye-sensitized solar cell (n-DSSC), an electron is injected into the conduction band of an n-type semiconductor (n-SC) from the excited state of the sensitizer. Comparatively few studies have examined the sensitization of wide bandgap p-type semiconductors. In a p-type DSSC (p-DSSC), the photoexcited sensitizer is reductively quenched by hole injection into the valence band of a p-type semiconductor (p-SC). The study of p-DSSCs is important both to understand the factors that control the rate of hole photoinjection and to aid the rational desi...