Energy demand Research Papers - Academia.edu (original) (raw)

An important fraction of the future energy demand may be satisfied by nuclear power. In this context, the possibilities of worldwide nuclear deployment are studied. We are convinced that the Molten Salt Reactors may play a central role in this deployment. The Molten Salt Reactor needs to be coupled to a reprocessing unit in order to extract the Fission Products which poison the core. The efficiency of this reprocessing has a crucial influence on reactor behavior especially for the breeding ratio. The Molten Salt Breeder Reactor project was based on an intensive reprocessing for high breeding purposes. A new concept of Thorium Molten Salt Reactor is presented here. Including this new concept in the worldwide nuclear deployment, to satisfy these power needs, we consider three typical scenarios, based on

- by
- •
- Waste Management, Energy demand, Nuclear power, Boolean Satisfiability
- by Hulya Sarak
- •
- Mechanical Engineering, Methodology, Energy, Consumption
- by Hamed Shakouri
- •
- Fuzzy set theory, Linear Programming, Forecasting, Energy Consumption

Energy sustainability is becoming an increasing issue—or rather “the” issue in our society. Often it is reduced to a purely technical problem. Renewable energies and energy-efficient technologies are developed to solve the problem, but finally the end-users will “decide” how much and what kind of energy they are going to consume. This article is targeted on showing the environmental psychological

- by Rainer Zah
- •
- Engineering, Energy demand, Crop Residue Burning, Energy Crop

Efficient and rational implementation of building stock CO 2 emission reduction strategies and policies requires the application of comprehensive building stock models that have the ability to: (a) estimate the baseline energy demand of the existing building stock, (b) explore the technical and economic effects of different CO 2 emission reduction strategies over time, including the impact of new technologies, and (c) to identify the effect of emission reduction strategies on indoor environmental quality.

- by Dejan Mumovic
- •
- Architecture, Energy Conservation, Energy Consumption, New Technology
- by Nevenka Hrovatin
- •
- Economics, Energy Policy, Demand Side Management, Electricity

The environmental consequences of replacing fish meal and fish oil with plant-based sources in salmonid feeds were investigated using Life Cycle Assessment (LCA). Two scenarios of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) farming were compared. The first scenario used a Standard Diet (STD) with high levels of fish meal and fish oil, and the second a Low Marine-Fishery-Capture Diet (LFD) in which fish meal and fish oil were replaced by plant protein and oil sources. Environmental impacts assessed were: acidification, eutrophication, climate change, terrestrial ecotoxicity, net primary production use (biotic resource use), water use, land occupation and total cumulative energy demand. The assessment confirmed the substantial contribution of feed to the environmental burdens of fish production and the LFD scenario led to a significant decrease in biotic resource use compared to the STD scenario with the same total energy demand. Environmental impacts of feeds depended highly on the geographic origins of feed ingredients from fishery (e.g., fish oil from Norway or Peru) and from terrestrial agricultural crop species (e.g., palm oil or rapeseed oil). This study demonstrated the importance of a multicriteria method to give stakeholders the most accurate information on the potential consequences of replacing fishery products with plant-based sources in aquafeeds.

- by Hayo van der Werf
- •
- Zoology, Climate Change, Life Cycle Assessment, Environmental Impact Assessment

Fermented food composts, to be recycled into fertilizer and animal feed, require sodium chloride concentrations to be less than 1 wt% due to several toxicities. Electrochemical methods are used to remove sodium ions from fermented food composts. By washing the compost with tap water (with no electric current applied), 48% of the initial sodium ion is removed. With an electric current density of 3 mA/cm2 (the distance between the electrodes is 16 cm), the removal efficiency increases to 96% for a 36 h operation. Major factors influencing the efficiency are the treatment time and the electric current density. Removal efficiency increases with energy demand to yield 96% removal at 60 Kwh/m2. Due to the difference in relative ionic mobility, less than 9% of calcium is removed, during the same operation time, which supports the feasibility of this method.

- by Hyun-Jae Shin
- •
- Mechanical Engineering, Chemical Engineering, Energy demand, Current Density

The paper develops an Applied General Equilibrium (AGE) model for the estimation of energy demand and applies it to the Spanish Economy. The price system is based in the classical (Sraffian) theory of prices of production. The quantity system is based on the Keynesian principle of effective demand supported by broad energy multipliers. Both systems have been adapted to the specificities of energy industries. The model is dynamic in nature since output and technology are evolving through time. Energy technical coefficients are declining at a specific rate that may be speeded up or slowed down after changes in prices of the different sources of energy. The "tendencies" and "elasticities" implied are computed by calibration and econometric methods.

- by Jorge Zafrilla
- •
- Energy demand

Southeast Asia enjoyed, until recently, one of the fastest economic growth in the world. This economic growth has caused both a surge in energy demand and a degradation of environmental resources in the region. Modern biomass cogeneration technologies can help to satisfy increasing energy needs while preserving the environment. This study presents estimates of the change in air emissions that would be associated with wide spread adoption of modern biomass cogeneration technologies by the food and agro-industries in Indonesia, Malaysia, The Philippines and Thailand. Results suggest that wide spread adoption of biomass cogeneration technology would result in a signiÿcant reduction in both greenhouse gas and criteria pollutant emissions.

- by Yann Duval
- •
- Engineering, Technology, Economic Growth, Biomass
- by Steve Wiseman
- •
- Biological Sciences, Environmental Sciences, Cortisol, FISH

maternal nestbuilding in Syrian hamsters: Interaction of ovarian steroids and energy demand. PHYSIOL BEHAV 58(1 ) 141 -146, 1995.--To investigate the relationship between energy demand, ovarian hormones, and behavioral thermoregulation, we measured nestbuilding of female Syrian hamsters (Mesocricetus auratus) under conditions where energy demand and circulating ovarian hormone levels varied. Hamsters increased nestbuilding trader conditions of chronically elevated estradiol and progesterone levels (late gestation; ovariectomized animals treated with estradiol ___ progesterone) and increased energy demand (late gestation or cold exposure). When hormone treatments were withdrawn, hamsters gained weight and reduced nestbuilding activity. Nestbuilding was not affected by lactation (characterized by low ovarian steroid levels and high energy demand) or by estrous cycle phase (characterized by relatively transient changes in ovarian steroid levels and subtle changes in energy demand). Thus, nestbuilding in Syrian hamsters was responsive to increased energy demand from cold exposure, late gestation, and to ovarian hormones. However, during lactation and estrous cycles, nestbuilding did not always change predictably according to known changes in energy expenditure and steroid hormone levels. Thus, levels of nestbullding are influenced by factors in addition to ovarian hormones and energy expenditure under some circumstances.

- by George Wade
- •
- Thermoregulation, Lactation, Energy Metabolism, Biological Sciences

Smart thermostats, combined with multiple temperature sensors, and home energy management systems (HEMS) are experiencing rapid growth worldwide. Meanwhile, behavioral science-based programs, such as energy feedback and energy saving tips, have been also gaining attention. Can the two strategies work together and save even more energy? An experimental program was undertaken in Sapporo, Japan – a climate similar to Minnesota – to assess the joint impact of these two strategies.
One hundred households participated in the program. The first group received a tablet with an energy saving app and a HEMS control system, whereas the second group received only the tablet with the app. The app was designed to stimulate behavioral change through recommendations regarding indoor temperature and humidity settings. It also gave energy consumption feedback and energy saving tips (utilizing “nudges” such as social norms and prompts). The HEMS control system was designed to automatically control heating based on schedules configured in advance.
The impact of the different strategies was evaluated with a randomized control trial (RCT). Energy consumption data 1 year after the interventions indicates that the combined treatments yielded about 3.5% reduction compared to the control, while the app alone achieved about 2.4% reduction in winter. We also found out that the usage of the app differs between the two groups, suggesting that the app results in different levels of reduction with and without the combination of the HEMS control system.

1] The goal of this study is to quantify the world's wind power potential for the first time from data. Wind speeds are calculated at 80 m, the hub height of modern, 77-m diameter, 1500 kW turbines. Since relatively few observations are available at 80 m, the Least Square extrapolation technique is utilized and revised here to obtain estimates of wind speeds at 80 m given observed wind speeds at 10 m (widely available) and a network of sounding stations. Tower data from the Kennedy Space Center (Florida) were used to validate the results. Globally, 1313% of all reporting stations experience annual mean wind speeds ! 6.9 m/s at 80 m (i.e., wind power class 3 or greater) and can therefore be considered suitable for low-cost wind power generation. This estimate is believed to be conservative. Of all continents, North America has the largest number of stations in class ! 3 (453), and Antarctica has the largest percent (60%). Areas with great potential are found in northern Europe along the North Sea, the southern tip of the South American continent, the island of Tasmania in Australia, the Great Lakes region, and the northeastern and northwestern coasts of North America. The global average 10-m wind speed over the ocean from measurements is 6.64 m/s (class 6); that over land is 3.28 m/s (class 1). The calculated 80-m values are 8.60 m/s (class 6) and 4.54 m/s (class 1) over ocean and land, respectively. Over land, daytime 80-m wind speed averages obtained from soundings (4.96 m/s) are slightly larger than nighttime ones (4.85 m/s); nighttime wind speeds increase, on average, above daytime speeds above 120 m. Assuming that statistics generated from all stations analyzed here are representative of the global distribution of winds, global wind power generated at locations with mean annual wind speeds ! 6.9 m/s at 80 m is found to be 1372 TW ($54,000 Mtoe) for the year 2000. Even if only $20% of this power could be captured, it could satisfy 100% of the world's energy demand for all purposes (6995-10177 Mtoe) and over seven times the world's electricity needs (1.6-1.8 TW). Several practical barriers need to be overcome to fully realize this potential.

- by Dimple Garg
- •
- Statistics, Energy, Multidisciplinary, Great Lakes Region

Electrochromic evacuated advanced glazing has been developed, combining optimum dynamic control of the solar radiation penetrating into buildings with a high degree of thermal insulation. This was achieved by the optimisation of the electrochromic device materials (electrochromic, ion storage, protective layers, transparent conductors and polymer electrolytes) and by the refinement of a sealing method for evacuated glazing. Electrochromic evacuated glazing prototypes with dimensions up to 40 cm Â 40 cm have been fabricated using vacuum techniques and chemical methods. The prototypes exhibit excellent optical and thermal performance, with a contrast ratio up to 1:32 (visible dynamic transmittance range T lum,bleached = 63% and T lum,colored = 2%), coloration efficiency up to 92 cm 2 /C and mid-pane U-values as low as 0.86 W m À2 K À1 . Their durability in relation to real working environmental conditions has been assessed through indoor and outdoor testing. Such a glazing can be used in building applications to improve occupant thermal comfort, contribute to a reduction in space heating and cooling loads and allow for increased areas of fenestration thereby reducing artificial lighting loads. These factors reduce the energy demand for the building and therefore contribute to the reduction of carbon dioxide emissions. #

- by Spiros Papaefthimiou
- •
- Engineering, Energy, Energy Efficiency Buildings, Dynamic control

Since the maturing of the wind farm industry, attention has been focused on the use of wind turbines for electricity production in remote areas. Generally, remote villages are driven by diesel generators. However, introduction/dissemination of wind energy conversion systems (WECS) into the existing diesel systems results in the reduction of the diesel fuel consumption and eventually allows atmospheric pollution to subside. A short-term energy storage integrated with wind-diesel system may compensate for fluctuations in the power output of the wind turbine and raise the fuel saving potential. The Kingdom of Saudi Arabia's (K.S.A) area is large, with large number of villages/settlements scattered all over the Kingdom. In the present study, hourly mean wind-speed data recorded at an airport, K.S.A., has been analyzed to investigate the technical and economic feasibility/viability of utilizing off-grid hybrid (wind-diesel-battery) power systems to meet the load requirements of a typical remote/isolated village with annual electrical energy demand of 13,244 MWh. The airport is located in the vicinity of the candidate settlement. The hybrid systems simulated comprise of various combinations (wind farms) of 600 kW commercial WECS supplemented with diesel generators and a short-term battery storage. The amount of battery storage capacity has been varied from 0 to 60 load minutes (equivalent to 0-60 min of average load). National Renewable Energy Laboratory's (NREL's) HOMER software has been used to perform the technical and economic analysis of hybrid wind-diesel-battery power systems. The investigation indicates that for a hybrid system consisting of 3.6 MW (six 600 kW wind machines, 50 m hub-height) wind farm capacity together with 4.5 MW diesel system (three 1.5 MW diesel units) and a battery storage of 30 load minutes (equivalent to 30 min of average load), the wind penetration is 24%. The cost of generating energy from the above hybrid configuration has been found to be 0.078 US$/kWh (assuming a diesel fuel price of 0.1 $/liter). The simulation results highlight that the number of operational hours of diesel generators in wind-diesel system decreases with increase in wind farm capacity. The study also illustrates that for a given hybrid wind-diesel system, the decrease in diesel run time is further enhanced by inclusion of battery storage capacity. An attempt has been made to address the effect of wind penetration, effect of hub-height on energy production, cost of wind-diesel-battery systems, cost of energy production, excess electricity, un-met load, percentage fuel savings and decrease in carbon emissions, etc (for different scenarios such as wind-diesel without storage, wind-diesel with storage, as compared to diesel-only situation).

- by Shafiqur Rehman
- •
- Mechanical Engineering, Renewable Energy, Power System, Sustainable Energy

Climate change and environmental issues have been increasingly in the forefront of the media and government agendas. However, despite much discussion and fanfare, little has been done in the way of serious commitment and clear course of actions since the adoption of the UN Framework Convention on Climate Change in 1992 to bring carbon emissions to sustainable levels. To tackle the immensity of the climate change challenge, a paradigm shift in understanding is necessary to balance the course of global human development with energy demand and consumption patterns. Accounting for over 40% of global energy demand and more than 30% of greenhouse gas emissions, the building sector offers the greatest mitigation potential for reducing carbon emissions in both the short and long term, with positive implications for a range of associated sectors and industries. Promoting behavioral change among end-users for reduced energy consumption as well as encouraging the building industry to embrace sustainable design, lowcarbon construction practices and materials, and renewable technologies, is fundamental to mitigating the impact of the built environment on planetary biospheres and preserving quality of life for generations to come. This paper starts by drawing attention to the building sector and related EU policy, outlining the challenges and opportunities for reducing energy consumption and carbon emission levels. Such policy provides the essential framework to engage stakeholders and allow supporting factors to foster progress in the sector. The paper contends that information on climate change has not led to significant improvements in meeting global targets and that what is needed is behavioral change among individuals and society as a whole. On the basis of research project experiences and literature review, it puts forth and explores five key elements contributing to behavioral change for reduced energy consumption and lower carbon emissions in the building sector, focused on: information and education; financial incentives and energy services; modern technologies and sustainable design; social and community norms; and biophilia (contact with the natural environment). The paper suggests opportunities for further research and concludes with recommendations for policy-makers and related stakeholders.

- by helen Santiago Fink
- •
- Economics, Climate Change, Human Development, Quality of life

Parallel cables used with the aim of meet growing energy demand at the energy systems which operates via cable. To use of parallel cables may bring out imbalance among the cables. This event, known as the current distribution imbalance, cause problems such as over heating on the high current-carrying cables, wear out of insulation and reduced life expectancy. In this study, effects of cable configurations by changing phase sequences and layouts are investigated via data obtained from a data center which recently goes a major upgrade. The cable configuration which has the most uniform current distribution is determined.

- by Mehmet Hakan Hocaoglu
- •
- Energy demand, Life Expectancy, Data Center, Energy System

The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.

- by Adom Philip
- •
- Energy Economics, Renewable Energy, Energy Policy, Multidisciplinary

Article CITATION 1 READS 78 4 authors, including: Some of the authors of this publication are also working on these related projects: Optoelectronic Properties of Nanofibres Zn-doped and Zr-doped Perovskite-type as Transparent and Conductive Oxide Films View project Photovoltaic Solar Thermal Technology (PV/T) View project Salwan S. Dihrab

- by Kamaruzzaman Sopian
- •
- Wind Energy, Wind turbine, Power Generation, Energy demand

The photocatalytic degradation of fenitrothion under UV and near visible light in the presence of polyoxometallate (POM) photocatalyst PW 12 O 40 3− , in aqueous solutions has been studied and compared with the photodegradation by TiO 2 suspensions. Fenitrothion is effectively degraded in the presence of both photocatalysts following pseudo first order kinetics. Complete mineralization of fenitrothion is achieved using both photocatalysts, leading to the formation of CO 2 and inorganic ions (PO 4 3− , SO 4 2− , NO 2 − , and NO 3 − ) as final products. Various inermediates, identical in the presence of both photocatalysts, have been detected and identified using HPLC and GC-MS techniques. The similarity of the intermediates by these two methods, i.e. PW 12 O 40 3− and TiO 2 tends to suggest, that the photodegradation mechanism of fenitrothion as other cases as well, takes place mainly via a common reagent, i.e. OH radicals. A photodegradation mechanism is proposed.

- by Paola Calza
- •
- Environmental Engineering, Chemical Engineering, Water, Catalysis

Besides technical parameters, consumer behavior is the most important issue with respect to energy consumption in households. In this paper, the results of a cross-section analysis of .4ustrian households are presented. The impact of the following parameters on residential energy demand for space heating have been invexigated: (i) thermal quality of buildings; (ii) consumer behavior; (iii) heating degree days;

- by Hans Auer and +1
- •
- Engineering, Energy Policy, Energy Conservation, Energy Efficiency Buildings

The increasing interest in the recuperation of the biogas coming from organic residues, associated with its energetic use is a subject that has been widely discussed. Biogas was merely seen as a sub-product obtained from anaerobic decomposition (without oxygen) of organic residue. In the paper is carried out an evaluation of the quantities of organic residues coming out from the sugar and alcohol industry (vinasse), urban solid and liquid wastes (garbage and sewage) and livestock residues (bovine and swine manure) in Brazil. Finally the electricity generation potential of biogas out of the evaluated sources of organic residues in Brazil is estimated. The results of this study indicate that the potential regarding the production of biogas out of the aforementioned organic residues of electricity production using could meet an energy demand of about 1.05 to 1.13 %. Constraints for biogas energy utilization are identified and discussed.

- by Electo Silva Lora
- •
- Engineering, Technology, Biogas, Alternative Energy

Costs GHG emissions a b s t r a c t In Italy, agro-energy's contribution to the national primary energy demand is still moderate. Among the energy crops Short Rotation Coppice (SRC) has taken up about 6500 ha, using poplar clones. For this crop, the harvesting operations, usually, are carried out by modified forage harvester equipped with dedicated headers and by tractor coupled with trailers. This, besides the high economic costs, involves also energy inputs and green house gas (GHG) emissions that must be carefully taken in account when the sustainability of the whole agro-energy chain is assessed. This study shows the results of filed tests carried out on 69.2 ha of biennial SRC with two different poplar plantation systems. Yield ranges from 16.7 to 33.71 t dm /ha (dry matter), chip moisture content between 50.4 and 64.8% and bulk density between 118.8 and 169.2 kg dm /m 3 . Effective field capacity and theoretical field capacity are highly variable, respectively, from 0.77 to 1.67 ha/h and from 1.18 to 2.15 ha/h. Economic cost, energetic input and GHG emissions depend on yield, annual use of the machines and scheduling of operations. The analysis shows that the best performances are achieved when harvest and transport are carried out on a area upper than 400 ha, with an efficient plantation design, a proper-sized transport system and without mechanical failures. In these case the productivity of the harvest-transport system can arrive at 65 t wb /h (wet basis) while the economic cost, the energetic input and the GHG emissions reach, respectively, 15 V/t dm , 212 MJ/t dm and 16 kgCO 2 eq/t dm . (J. Bacenetti).

- by Jacopo Bacenetti
- •
- Engineering, Technology, Biomass, Energy

Industries worldwide depend upon pumping systems for theirdaily operation. These systems account for nearly 20 percent of theworld's industrial electrical energy demand and range from 25-50 percentof the energy usage in certain industrial plant operations. Purchasedecisions for a pump and its related system components are typicallybased upon a low bid, rather than the cost to operate the system over itslifetime.

- by Aimee McKane and +1
- •
- Energy demand, System Reliability, Energy Optimization, System Development

Per capita consumption 1 of electricity in India is many folds lesser than Canada, USA, Australia, Japan, Chaina and world average. Even though, total energy shortage 2 and peaking shortage 3 were recorded as 11.2% and 11.85%, respectively, in 2008-09 reflecting non-availability of sufficient supply of electricity. Performance improvement of very small amount can lead to large contribution in financial terms, which can be utilized for capacity addition to reduce demand supply gap. Coal fired thermal power plants are main sources of electricity in India. In this paper, relative technical efficiency of 60 coal fired power plants has been evaluated and compared using CCR and BCC models of data envelopment analysis. Target benchmark of input variables has also been evaluated. Performance comparison includes small versus medium versus large power plants and also state owned versus central owned versus private owned. Result indicates poor performance of few power plants due to over use of input resources. Finding reveals that efficiency of small power plants is lower in comparison to medium and large category and also performance of state owned power plants is comparatively lower than central and privately owned. Study also suggests different measures to improve technical efficiency of the plants.

- by Kavita Chauhan
- •
- Energy Policy, Multidisciplinary, Power Plant, Energy demand

Miscanthus 'Giganteus' is a perennial Cd-grass from East Asia. The biomass yield-potential of Miscanthus has been investigated in Germany since 1987. The combustion of biomass offers a possibility for lowering emissions of the greenhouse gas COr. The CO2 which is set free during combustion has previously been fixed by the plants. The study analyses the demand for energy and the COremissions which are involved in the production of Miscanthus, beginning with propagating the plants to transporting the biomass to the power station. Energy demand and COr-emissions are compared with those of the provision and combustion of hard coal. The energy content of Miscanthus biomass harvested from one hectare, about 20 t of dry matter, corresponds to the energy content of 12 t hard coal. For each gigajoule of hard coal, 96.6 kg COZ are emitted during provision and combustion. By combusting Miscanthus instead of hard coal 90% of CO*-emissions can be saved.

- by Andreas Kicherer
- •
- Engineering, Technology, East Asia, Energy demand

Soybean production and its supply chain are highly dependent on inputs such as land, fertilizer, fuel, machines, pesticides and electricity. The expansion of this crop in Brazil in recent decades has generated concerns about its environmental impacts. To assess these impacts, two representative chains supplying soybeans to Europe were identified: Center West (CW) and Southern (SO) Brazil. Each supply chain was analyzed using Life Cycle Assessment methodology. We considered different levels of use of chemical and organic fertilizers, pesticides and machinery, different distances for transportation of inputs and different yield levels. Because transportation contributed strongly to environmental impacts, a detailed study was performed to identify the routes used to transport soybeans to seaports. Additionally, we considered different levels of land occupation and land transformation to represent the impact of deforestation in the CW region. Environmental impacts were calculated for 1000 kg of soybean up to and including the delivery to Europe at the seaport in Rotterdam, at 13% humidity. Overall results showed that the impacts are greater for CW than for SO for all impact categories studied, including acidification (7.7 and 5.3 kg SO 2 eq., respectively), climate change (959 and 510 kg CO 2 eq.), cumulative energy demand (12,634 and 6,999 MJ) and terrestrial ecotoxicity (4.9 and 3.1 kg 1,4-DCB eq.), except eutrophication and land occupation. The same trend was observed for the crop-production stage. Efforts to reduce chemical fertilizers and diesel consumption can reduce CO 2 emissions. Although deforestation for crop production has decreased in recent years, the contribution of deforestation to climate change and cumulative energy demand remains significant. In the CW scenario deforestation contributed 29% to climate change and 20% to cumulative energy demand. Results also showed that although there are different transportation options in Brazil, the current predominance of road transport causes severe environmental impacts. In CW, road transport contributed 19% to climate change and 24% to cumulative energy demand, while in SO it contributed 12% and 15% to these impacts, respectively. Improvements in the logistics of transportation, giving priority to rail and river transports over road transport, can contribute significantly to reducing greenhouse gas emissions and decreasing energy use. Future studies involving Brazilian soybeans should take into account the region of origin as different levels of environmental impact are predicted.

- by Vamilson Da Silva and +3
- •
- Climate Change, Environmental Management, Brazil, Agriculture

The rapidly increasing electricity demand for data center operation has motivated efforts to better understand current data center energy use and to identify strategies that reduce the environmental impact of these buildings. This paper builds on previous data center energy modeling efforts by characterizing local climate and mechanical equipment differences among data centers and then evaluating their consequences for building energy use. Cities in the United States with significant data center activity are identified. Representative climate conditions for these cities are applied to data center energy models for several different prototypical space types. Results indicate that widespread, effective economizer use in data centers could reduce energy demand for data centers by about 20e25%, equivalent to an energy efficiency resource in the US of ∼13e17 billion kWh per year. Almost half of the potential savings would result from better airflow management and proper control sequences. The total energy savings potential of economizers, although substantial, is constrained by their limited potential for use in server closets and server rooms, which together are estimated to account for about 30% of all data center energy demand. Incorporating economizer use into the mechanical systems of larger data centers would increase the variation in energy efficiency among geographic regions, indicating that as data center buildings become more energy efficient, their locations will have an increasing effect on overall energy demand. Differences among regions become even more important when accounting for greenhouse-gas emissions. Future data center development could consider site location, along with efficiency measures, to limit the environmental impact attributable to this increasingly prominent economic sector.

- by Arman Shehabi
- •
- Architecture, Climate Change Mitigation, Energy demand, United States

Recent studies on the Uganda geothermal systems have focused on three geothermal prospects, Katwe, Buranga and Kibiro, all located in the tectonically active and Recent volcanic belt in the Western Rift valley along the border of Uganda and the Democratic Republic of Congo. Geothermal systems and saline and fresh water lakes characterize the Rift Valley. The three areas were chosen for study because of their volcanic and tectonic features that indicate a powerful heat source and high permeability. The objective is to develop geothermal energy as an alternative energy source to hydro and others to meet the energy demand of rural areas in sound environment. The geology and geochemistry results for the surface hot springs indicate that potential geothermal systems exist at depth. The subsurface temperatures of 160-200°C, 200°C, and above 200°C for the Katwe, Buranga and Kibiro prospects, respectively, have been inferred by geothermometry and mixing models. These temperatures are suitab...

- by Godfrey Bahati
- •
- Geology, Energy Consumption, Alternative Energy, Democratic Republic of Congo

A comparison between photovoltaic hybrid systems (PVHS), standalone photovoltaic (PV) and standalone diesel generator options is performed using the net present value (NPV) technique. A typical village mini-grid energy demand of 7.08 kWh/day is considered in the computation of energy costs and breakeven grid distances. A first sensitivity analysis is conducted using remote diesel prices of 0.8 V/l, 0.98 V/l, 1.12 V/l, 1.28 V/l with a PV module cost of 7.5 V/Wp. A second sensitivity analysis is also done using PV module costs of 5.25 V/Wp, 6 V/Wp, 6.75 V/Wp, 7.5 V/Wp with a diesel price of 1.12 V/l. The energy cost for the diesel option was found to be 0.812 V/kWh at a diesel fuel price of 1.12 V/l. The sensitivity analyses showed that minimum energy costs were attained in PVHS at renewable energy fractions in the range 82.6e95.3%. In the second sensitivity analysis the energy costs and breakeven grid distances were found to be in the ranges 0.692e0.785 V/kWh and 5.1e5.9 km respectively. For a PV module cost of 5.25 V/Wp, the lowest energy cost for the PVHS option was 0.692 V/kWh at a final renewable energy fraction of 95.3% with the diesel generator hours being 37 h compared to 2075 h in the standalone diesel generator option. Consequently, a 30% reduction in custom duties and taxes on imported PV modules and sub-systems would increase the use of small-scale and climate friendly PV mini-grids in remote areas of far north Cameroon that have an annual insolation of at least 5.55 kWh/m 2 /day.

- by Eustace NFAH
- •
- Mechanical Engineering, Renewable Energy, Sensitivity Analysis, Energy demand

Whether the environmental benefits of emerging technologies are outweighed by the environmental impacts of producing and using scarce technology metals remains an open question. We present a threelevel approach to assess how increasing environmental impacts on the resource provision level affect the overall impacts on the product level and on the service level, at an early stage of technology implementation. The approach is described based on a case example: we evaluate the environmental impacts of different supply options for lithium carbonate (Li 2 CO 3 ) e required for the production of Li-ion batteries e and their influence on the environmental impacts associated with an electric vehicle (EV). We applied the methodology of Life Cycle Assessment (LCA) and considered the production of Li 2 CO 3 from three different deposit types: natural brines (currently dominant), ores (less common) and seawater (hypothetical future option). For each of the three supply options, we established an inventory dataset for both favorable and unfavorable processing conditions. The inventory datasets were combined with those used in a recently published LCA, which compared the environmental impacts of an EV with those of an internal combustion engine vehicle (ICEV). The results of this study indicate that the environmental impacts of Li 2 CO 3 production as a percentage of the total transportation impacts caused by an EV are currently negligible. Only if seawater was used under unfavorable processing conditions, these impacts could outweigh the environmental benefits of EV over an ICEV; however, the uncertainty is high due to the limited data availability regarding future lithium production processes. The break-even point for the environmental impacts of 1 km driven with an EV and with an ICEV would be reached only if the impacts per kilogram of Li 2 CO 3 were increased by about two orders of magnitude (more than 200 times higher for the impact assessment method Cumulative Energy Demand, about 450 times higher for Global Warming Potential and about 100 times higher for ecoindicator 99).

An energy resource that is renewed by nature and whose supply is not affected by the rate of consumption is often termed as renewable energy. The need to search for renewable, alternate and non-polluting sources of energy assumes top priority for self-reliance in the regional energy supply. This demands an estimation of available energy resources spatially to evolve better management strategies for ensuring sustainability of resources. The spatial mapping of availability and demand of energy resources would help in the integrated regional energy planning through an appropriate energy supply-demand matching. This paper discusses the application of Geographical Information System (GIS) to map the renewable energy potential talukwise in Karnataka State, India. Taluk is an administrative division in the federal set-up in India to implement developmental programmes like dissemination of biogas, improved stoves, etc. Hence, this paper focuses talukwise mapping of renewable energy (solar, wind, bioenergy and small hydroenergy) potential for Karnataka using GIS. GIS helps in spatial and temporal analyses of the resources and demand and also aids as Decision Support System while implementing location-specific renewable energy technologies.

- by Jafaru Abdulrahman
- •
- Engineering, Spatial Analysis, Renewable Energy, Wind Energy

With the current interest in controlling greenhouse gases, there is a new focus on materials that can discriminate between gas molecules by capturing those gases which must be curtailed and releasing those which pose no adverse effects to the atmosphere. Although zeolites can be applied to such tasks, molecular sieve (MS) carbons have an additional advantage in their ability to both adsorb and desorb molecules cyclically with comparatively little energy demand.

- by Sri Atmi
- •
- Engineering, Power Plant, Energy demand, Molecular Sieve

Studies of energy use at the household level show a large degree of variability in consumption that cannot be entirely explained by infrastructural differences. For example, families living in identically-designed homes use strikingly different amounts of energy. These findings were responsible for highlighting the influential role of the occupant in energy demand some thirty years ago. The extent of this variability also implies that there are no "typical" energy-using households within a society. This paper reviews evidence of the variability in domestic energy consumption and presents data from student apartments in a UK university where both the infrastructure and the number of occupants are comparable. As expected, the variability in consumption is less in this homogeneous sample than previously reported in heterogeneous samples of households. Nonetheless, there is variation, particularly in electricity consumption, that can only be explained by reference to some kind of occupantrelated feature(s). Further qualitative enquiry explores the idea that this difference arises from the practices of the occupants. It is clear that practices do vary between households. This paper develops hypotheses regarding the resulting differences in energy use. To explore these hypotheses, detailed micro-level consumption data is required. But this is difficult data to gather empirically and is not available here, nor widely reported in the literature. However, a framework based on practices could provide a cross-cutting and meaningful structure to relate details of micro-variations to macro-level understanding of the dynamics of energy demand in a society. In this way, analysis based on a practice theory perspective offers much potential to understand and interpret the variation in domestic energy consumption. In particular, it challenges any view that such difference, as it currently exists, is due to idiosyncrasies of individual behaviour.

- by Janine Morley
- •
- Practice theory, Energy Consumption, Energy demand

This brief review focuses on health and biological function as cornerstones of fish welfare. From the function-based point of view, good welfare is reflected in the ability of the animal to cope with infectious and non-infectious stressors, thereby maintaining homeostasis and good health, whereas stressful husbandry conditions and protracted suffering will

- by Fredrik Jutfelt
- •
- Fisheries, Ecology, Animal Welfare, Health

Medium-term electric energy demand forecasting is a useful tool for grid maintenance planning and market research of electric energy companies. Several methods, such as ARIMA, regression or artificial intelligence, have been usually used to carry out those predictions. Some approaches include weather or economic variables, which strongly influence electric energy demand. Economic variables usually influence the general series trend, while weather provides a periodic behavior because of its seasonal nature. This work investigates the periodic behavior of the Spanish monthly electric demand series, obtained by rejecting the trend from the consumption series. A novel hybrid approach is proposed: the periodic behavior is forecasted with a Fourier series while the trend is predicted with a neural network. Satisfactory results have been obtained, with a lower than 2% MAPE, which improve those reached when only neural networks or ARIMA were used for the same purpose.

- by Diego Fernandez Gonzalez
- •
- Time Series, Forecasting, Energy Conversion, Neural Network

Energy demand from hot tap water usage on individual level has been modelled from data in time use diaries of 179 Swedish households living in detached houses and apartments. Data of activities that involve hot tap water was extracted and converted into energy - time diagrams (user profiles). The report describes the procedure to first convert each type of activity to an amount of hot water and secondly into energy. It was found that the energy use profiles for hot water consumption vary considerably between individual households. The average user profile of all households was compared to models of hot water use in two of the more frequently used simulation tools for solar thermal systems. It is shown that the profiles in the simulation tools are significantly different from the profiles modelled in this study. In a following study it will be investigated how these differences influence an optimal use of solar energy in a solar thermal system.

- by Kajsa Ellegård
- •
- Time Use, Solar Energy, Energy demand, User profile

The UK has a legally binding commitment to reduce CO 2 levels by 80% by 2050 relative to the 1990 emissions baseline. The existing housing stock, which accounts for approximately 30% of total UK energy demand, has the potential to provide significant opportunities for this reduction; however, currently there are no legislative measures driving widespread low carbon housing refurbishment (LCHR) design and construction. Architects have a decisive role to move forward the LCHR agenda owing to their leadership and significant involvement in the initial briefing, conceptual and design development phases of a project, regardless of project procurement types and project sizes. Hence, the aim of this research is to investigate the key challenges and incentives for achieving LCHR in England from architects' perspectives.

- by Mohamed Osmani
- •
- Architecture, Energy demand, Legislation, Building

Utilizing local materials for improving the energy demand in the single landed houses in Indonesia is very promising, since it also entails less cost during production and transportation. Many possible scenarios have been proposed towards this end such as improving building craftsmanship, using double walls with cavity, double walls with bamboo in between and introducing less transparent glass. The scenarios are tested in terms of the additional initial investment in terms of energy and cost and the benefits accrued for life cycle energy and cost. Energy and cost payback are computed to evaluate each scenario and a framework proposed for quick screening of building materials.

This review focuses on the characteristics of tennis players during match play and provides a greater insight into the energy demands of tennis. A tennis match often lasts longer than an hour and in some cases more than five hours. During a match there is a combination of periods of maximal or near maximal work and longer periods of moderate and low intensity activity. Match intensity varies considerably depending on the players' level, style, and sex. It is also influenced by factors such as court surface and ball type. This has important implications for the training of tennis players, which should resemble match intensity and include interval training with appropriate work to rest ratios.

- by Babette Pluim
- •
- Engineering, Education, Tennis, Energy Metabolism
- by Prof. Dr. Saad Mekhilef
- •
- Engineering, Biodiesel, Information Extraction, Alternative Energy

Energy planning for mixed energy distribution systems is important to increase the flexibility in the regional and national energy systems. Expected maximum loads, load profiles and yearly energy demands, all divided into heat and electricity purposes, are important input parameters to plan for the most economical, technical and environmental optimal energy distribution system for a planning area. First, this article presents a load prediction method which estimates heat and electricity load profiles for various building categories. The method is based on statistical analyses of hourly simultaneous measured district heat and electricity consumption in several buildings, as well as background information of the measured buildings. The heat load model is based on regression analyses, whereas the electricity load model is based on various statistical distributions. Second, a method for load aggregation based on the building categories' load profiles is presented to estimate the maximum load demands, yearly load profiles, load duration profiles and yearly energy demands, all divided into heat and electricity purposes, for a planning area. #

- by Rolf Ulseth and +1
- •
- Engineering, Energy Efficiency Buildings, Energy demand, Electricity Consumption

Electric mobility is considered as a promising option for future individual transportation in terms of lower -emissions and reduced dependence on fossil fuels. In order to analyze its impacts effectively, an agent based model is proposed. It integrates three domains which are mainly affected by electric mobility. Vehicle fleet evolution and vehicle energy demand simulations are combined with a transportation simulation, thus determining the daily behavior of electric vehicles and providing individual battery energy levels at the different locations of the vehicles during the day. Further, a power system model combined with a charging control algorithm is included in order to study general effects in electricity networks and to provide insights into new electric vehicle load patterns, as well as into changes in transport behavior. It is shown that network congestion can be mitigated using control signals. The paper describes the method and the integration of the three different domains and shows results of the integrated analysis tool.

- by Matthias Galus
- •
- Power Systems, Power System, Energy Consumption, Intelligent Transport System

Photovoltaic systems are now widely used technologies that are utilised to enhance a building's energy performance. Among the photovoltaic cell types, semitransparent devices have recently found a broader field of application thanks to... more

- by Vittorino Belpoliti
- •
- Energy demand, Legislation, Economic analysis, Case Study

Negli ultimi anni, l’integrazione di programmi di Demand Side Management è stata relativamente poco diffusa nei mercati energetici europei. Il Demand Side Management può essere definito come un ampio insieme di azioni che possono venire intraprese dal cliente in risposta a condizioni particolari nel sistema energetico (come ad esempio: periodi di congestione e di picco o prezzi elevati). Questo capitolo si prefigge di esaminare le ragioni che hanno portato ad un basso livello di penetrazione del Demand Side Management in Europa con riflessioni sui fattori che potrebbero influire una maggiore penetrazione in futuro, soprattutto in seguito alll’introduzione di Capacity Mechanisms. A questo scopo, il capitolo si avvale di una revisione della letteratura anche empirica su programmi di Demand Side Management già in essere. I risultati evidenziano come cambi nel sistema normativo, nella regolazione e nella tipologia di investimenti potrebbero modificare il ruolo del Demand Side Management in Europa. Per esempio, l’esperienza britannica indica che un cambiamento nella durata dei contratti di carico potrebbe favorire la partecipazione di una ben più ampia gamma di clienti di quelli attualmente impegnati nei mercati di Demand Side Management.

- by Jacopo Torriti
- •
- Demand Response, Demand Side Management, Energy demand

The aim of the Green Brewery Concept is to demonstrate the potential for reducing thermal energy consumption in breweries, to substantially lower fossil CO 2 emissions and to develop an expert tool in order to provide a strategic approach to reach this reduction. Within the project "Green Brewery" three detailed case studies have been performed and a Green Brewery Concept has been developed. The project outcomes show that it is preferable to develop a tool instead of a simple guideline where a pathway to a CO 2 neutral thermal energy supply is shown for different circumstances. The methodology of the Green Brewery Concept includes detailed energy balancing, calculation of minimal thermal energy demand, process optimization, heat integration and finally the integration of renewable energy based on exergetic considerations.

Hydrogen production by a proton exchange membrane (PEM) electrolyzer provides a promising way to store and better utilize the renewable energy resources. Presently, theoretical studies on PEM electrolyzer are still limited, impeding its technological development. Detailed thermodynamic analysis is valuable to identify the key losses and to optimise the performance of PEM electrolyzer plant for hydrogen production. In this study, energy and exergy analysis has been conducted to investigate the thermodynamic-electrochemical characteristics of hydrogen production by a PEM electrolyzer plant. One important feature of this model is that detailed electrochemical characteristics of the PEM electrolyzer are fully incorporated into the thermodynamic analysis. Heat production in the PEM cell due to irreversible losses has been investigated and compared with the thermal energy demand of PEM cell. It is found that a PEM electrolyzer normally operates in an exothermic mode as the heat production due to overpotentials exceeds the thermal energy demand. As the electrical energy input dominates the overall energy input, the exergy efficiency is found about the same as the energy efficiency. Parametric analyses have been performed to investigate the effect of important design and operating parameters on the plant energy conversion efficiency. This study has quantified how much the energy efficiency can decreases by increasing the operating temperature, lowering the current density, reducing the electrolyte thickness, and increasing the electrode catalytic activity. The analysis presented in this paper also offers better understanding of the characteristics of PEM electrolyzer plant for hydrogen production. With additional energy analysis of electricity generated from solar cells or wind turbines, the model presented in this paper is ready for complete energy/exergy analysis of advanced renewable electrolytic hydrogen production plants.

- by Mateusz Bryk
- •
- Thermodynamics, Solar Cell, Proton Exchange Membrane, Energy Conversion