Average Energy Intensity Research Articles

Report of Energy Audit in Building F1, F3, F4, and G6 of Universitas Muhammadiyah Yogyakarta

Energy audits on buildings are carried out to determine the load profile of electrical energy usage and to avoid wasting electricity. This energy waste can cause the use of electricity in buildings that are not efficient. An electrical energy audit is carried out to produce actual data that is in accordance with existing building conditions. This study conducted on buildings F1, F3, F4, and G6 in Universitas Muhammadiyah Yogyakarta to determine the value of the intensity of energy consumption used, whether it is following the Indonesian National Standards Agency. Measurement of electrical energy consumption using a tool that is the Power Factor Analyzer. The results of the calculation of the value of the intensity of electrical energy consumption showed that the buildings of F1, F3, F4, and G6 at the Universitas Muhammadiyah Yogyakarta obtained an average energy intensity value of 10.18 kWh/month. In this case, building standards are known to be between 7.92 - 12.08, which means that the building standards are categorized as efficient because they are under established standards. Furthermore, the use of electrical energy consumption used in buildings F1, F3, F4, and G6 in Universitas Muhammadiyah Yogyakarta in a month that is equal to 190,952.769 kWh/month.

Thermal energy demand and potential energy savings in a Spanish surgical suite through calibrated simulations

Hospitals present a widely recognized margin for energy conservation due to their elevated final energy use intensity. Specifically, operating rooms are among the functional areas with greatest energy demand in hospitals, given the stringent indoor conditions for patients and surgical staff. However, energy efficiency in surgical facilities has traditionally been overlooked by the scientific literature in favor of guaranteeing adequate air quality conditions. This paper assesses the potential energy savings that could be achieved in a surgical suite in a Spanish hospital by lowering the current ventilation rates to the lowest energy-demanding values recommended by the proper Spanish standard and other international codes. Likewise, the paper assesses the actual hygrothermal and ventilation conditions in the suite based on the results of a continuous monitoring campaign performed for a period of 12 days. Simulations undertaken with a dynamic energy model specifically developed and calibrated for this work revealed that the average energy intensity of the suite is 1021 kWh/m2/year (1685 kWh/m2/year for operating rooms), with 80% of the total annual thermal demand corresponding to periods of inactivity. In addition, energy savings between 40% and 80% are possible while complying with both national and international standards.

Preliminary Energy Assessment of Glass Production in Nigeria

This article describes how the high energy consumption associated with glass factories has been responsible for high cost of manufacturing of glass. However, there is a need for a systematic approach to assess energy consumption in the factory in order to avoid wastage. Previous methods of assessment could not take into cognizance of assessing the entire unit. Additionally, the methods are mostly complex and not straight forward"To overcome these constraints, an approach for audit energy consumption was developed. Energy study was conducted in a glass production plant in Ughelli, Nigeria to determine the energy requirements for the production of glass. The energy consumption patterns of the units operations were evaluated for production of 200 tonnes of glass bottles. The analysis revealed that there were ten defined units in a glass production. The electrical, thermal and manual energy required for the productions were 84.31, 15.59 and 0.10% of the total energy, respectively. The average energy intensity was estimated to be 818.53 MJ/tonne. The most energy intensive operation was identified as the melting process of the furnace with an energy intensity of 395.94 MJ/tonne, which accounts for 48.37% of the total energy required for glass production. Improvement on the design of the melting furnace is suggested to make the system more energy efficient.

Tillage and crop straw methods affect energy use efficiency, economics and greenhouse gas emissions in rainfed winter wheat field of Loess Plateau in China

ABSTRACTData from a field experiment conducted in China's Loess Plateau (2013–2015) were used to determine the energy balance of winter wheat (Triticum aestivum L.) as affected by tillage and straw treatments. Tillage treatments included chisel plow, no tillage, and mouldboard plow. Crop straw levels included straw returning and straw removed. The energy balance was evaluated by comparing the following parameters: net energy, energy profitability, energy use efficiency, and energy intensity. The yield parameters were significantly influenced by the tillage treatments and revealed that the chisel plow entailed fewer field operations and lower energy requirements with a higher yield than mouldboard plowing tillage. The highest proportion of energy input came from a nitrogen fertiliser, followed by diesel fuel. The total energy input applied per hectare increased with an increase in the tillage intensity, and the lowest energy input was required for the no tillage case with the straw returning treatment, and the highest for the case of mouldboard plow with the straw returning treatment. The lowest average energy intensity was recorded for the no tillage case, followed by the case of chisel plow tillage in both cropping seasons. Moreover, in the case of mouldboard plough tillage, the maximum energy intensity was recorded in both cropping seasons. In the cases of the chisel plow tillage and the no tillage, we observed the maximum energy gain, while in the no tillage case, we observed the maximum energy use efficiency. The net return and the benefit/cost ratio were higher in the case of straw returning than those in the case of no straw treatment. We concluded that no tillage and chisel plow tillage with straw returning could improve the energy use efficiency and the benefit/cost ratio of winter wheat production systems.

Exergetic analysis of breakfast cereal production in Nigeria

This work comprehensively studied energy and exergy analyses of breakfast cereal production in Nigeria. The process analysis method of energy accounting wa s used to evaluate the energy requirement for each of the five defined unit operations. The total energy used in the operation is 1,287.94 MJ. The types of energy used in breakfast cereal production were electrical, thermal and manual and the respective pe rcentages are 48.87%, 50.53% and 0.60%. It was estimated that an average energy intensity of 11.27 MJ/kg was required for the production of breakfast cereals. The most energy intensive operation was identified as the mixing operation followed by milling with energy intensities of 665.10 MJ/kg and 383.04 MJ/kg, respectively. The exergy analysis revealed that the roller dryer was responsible for most of the inefficiency (over 65.94%) followed by the wet mixer (27.40%). Suggestions for energy saving which will help in the reducing the high expenditure on energy and thus improve the profit margin were provided. Keywords : Energy, Exergy, Efficiency Breakfast Cereal

Theoretical calculation of Kα and Kβ X-ray satellite and hypersatellite structures for hollow argon atoms

A systematical knowledge of the satellite and hypersatellite structures of X-ray transitions is of great interest for various research areas, such as the explanation of the X-ray radiation from universe, plasma diagnostics, extreme ultraviolet (EUV) and X-ray sources and so on. Among these researches, the detailed explanation of the complex structures of X-ray satellites and hypersatellites are crucial for understanding the X-ray emission mechanism and the hollow atom formation mechanism. In this paper, the Kα and Kβ X-ray satellite and hypersatellite structure are theoretically studied for hollow argon atoms with the relativistic multiconfiguration Dirac-Fock (MCDF) method, which includes the Breit and quantum electro-dynamics (QED) corrections. To check the applicability of the method, the transition energies and rates of the diagram lines for Ar are calculated,. and the results are in agreement with previously published data. Then the MCDF calculations of the transition energies and probabilities of Kα 1, 2 (K →L3, 2) and Kβ 1, 3 (K → M3, 2) X-ray satellites and hypersatellites, which originate from the argon atoms with additional vacancies in the L shell, are carried out. To obtain the overall profile of the K X-ray spectrum, the diagram lines are integrated with the satellites and hypersatellites on the assumption that the intensity is proportional to the corresponding transition probability and each discrete line has a Gaussian distribution profile with a full width at half maximum (FWHM) value of 20 eV. From the convoluted profile, we can obtain the dependence of the average transition energy and relative transition intensity of the satellites and hypersatellites on the initial hollow configuration. It is found that the transition energy shift increases linearly with the number of spectator vacancies in the L shell increasing. For instance, the energy shift of the Kα satellite caused by L-shell hole is about 20 eV, and that of the Kβ satellite is 48 eV. While for hypersatellite, the energy shift increases greatly due to the double ionization in the K shell. The energy shift increment of Kα and Kβ hypersatellites corresponding to L vacancy are 21 and 52 eV, respectively. Finally, four simple empirical formulae for estimating the energy shifts of the Kα, Kβ X-ray satellites and hypersatellite for Ar atom with any number of L-shells vacancies are deduced by using the least square method. These results are useful in explaining various K X-ray spectra and better understanding the collision process.

Simulation and study of strength properties of rocks by measuring characteristics during the blast holes drilling

The article shows the results of the development of a method for obtaining information on the strength properties of an massif in the process of drilling of blast holes. This method is developed for open-cast mining and serves to increase the effectiveness of mass explosions. The order of operations is shown and the equipment is described for obtaining the necessary measured characteristics for the subsequent simulation of the distribution of rocks in the volume of the local block of the massif. The paper presents an approach to simulating of a threedimensional model of rock distribution from the difficulty of drilling in the volume of a local block that is subject to explosive destruction. The results of approbation of the equipment and simulation procedure at a large mining enterprise OJSC "Uralasbest" when blast holes are drilled with roller-type drill rig are presented. As a result of the approbation of the equipment, the values of the average power consumption for the drilling of one meter of the well were set by the machine tool, the fraction of power attributable to the auxiliary operations, and the average energy intensity of the fracture (by the rotator power, without taking into account the compressor's cost for blowing the well). Based on the test results, a digital model has been developed that has made it possible to improve the quality of studies on strength properties of rocks in an experimental local block prepared for explosive destruction.

Energy consumption and activity patterns: An analysis extended to total time and energy use for French households

Household lifestyles, and activity patterns in particular, greatly influence household energy use. In this paper we analyse the disparities in current activity patterns and related energy consumptions and expenditures of households, for a comprehensive set of everyday activities covering 24h. Thanks to detailed data on energy consumption by end use, we are able to allocate the total of household energy consumptions to the appropriate activities. We comment on average energy and expenditure intensities of time uses of the total population as well as of income, household-composition and housing-type subgroups. Income, an obvious driver of energy and expenditure intensities, is revealed to influence time use as well. Household composition and housing type are also associated with substantial variations in activity patterns and in the energy and expenditure intensities of activities, even within a given income group. Indeed, sometimes the variations associated with income are smaller than the variations associated with other variables. We therefore underline the importance of household disaggregation in household energy analyses, to properly account for such disparities.

Modeling technological change and its impact on energy savings in the U.S. iron and steel sector

Market penetration of energy-efficient technologies can be estimated using energy optimization models that minimize cost; however, such models typically estimate the minimum cost of optimal pathways under a certain set of non-dynamic assumptions, so technology penetrations determined for the long-term do not fully respond to changing circumstances or costs. In this study, investment costs of energy-efficient technologies are modeled dynamically in the Industrial Sector Energy-Efficiency Model (ISEEM) using a technological learning formula. Results from 24 energy-efficient technologies – 14 existing, 10 emerging – selected from the United States (U.S.) iron and steel sector show that when technological learning is incorporated into the model, total energy consumption of this sector is expected to decrease by 13% (180 PJ) in 2050 compared to energy consumption in a non-learning scenario. Average energy intensity of the steel production improves from 12.3GJ/t in the non-learning scenario to 10.7GJ/t in the learning scenario in 2050. This decrease represents a cost savings of US$1.6 billion and a carbon dioxide emissions reduction potential of 14.9 billion tonnes. Results discussed in this paper focus on the U.S. iron and steel sector, but the proposed framework can be applied to study new technology development in any other industrial processes and regions.

Energy performance of dwelling stock in Iceland: System dynamics approach

Despite the significant energy use in dwellings, buildings have the highest energy savings potential among all sectors. One of the main analytical challenges is how to capture the impact from inertia driven by the current dwelling stock. Thus, a dwelling stock model was established to study the impacts of physical processes (e.g., aging), as well as the effect of social processes (e.g., household energy conservation behaviors) on energy demand for space heating in the Icelandic dwelling stock. The model is initialized in the year 2000, and then calibrated with datasets on the Icelandic dwelling stock and hot water consumption for residential space heating. Analysis of the base scenario confirms that the improvement in the average energy intensity of total dwelling stock with regular turnover of the dwelling stock is insignificant and gradual, which relates to the inertia of the existing stock. The comparison of the results from two policy scenarios with the base case, illustrates that the aggressive demolition is more effective compared to the aggressive construction in reducing the total energy demand for space heating. The results of this analysis can support policy makers by providing insights regarding the potential impact of building energy-efficiency policies ensuring an effective policy package.

Radioactive isotopes betavoltaic generator technology

In this article we have analyzed radioactive isotope applications in the technology of autonomous power supplies and the materials used in radioisotope thermoelectric generators (RTGs), justified the advantage of manufacturing betavoltaic generators, compared them with other electric power sources and considered the mechanism of β −decay and positioned it among other types of nuclear transformations. We have also drawn up the basic radiation safety requirements to the materials used for the hull and the converter, analyzed some earlier designs of radioisotope betavoltaic sources and set up a list of isotopes suitable as energy sources in betavoltaic generators. Furthermore, we have analyzed methods of obtaining radioactive materials which exhibit β −decay, their basic properties and abundance in nature. In conclusion, the choice of nickel−63 isotope has been selected as preferable for betavoltaic generators due to the optimum combination of half−life, average particle energy and radiation intensity.

Interlinking climate change with water-energy-food nexus and related ecosystem processes in California case studies

Global climate change creates critical challenges with increasing temperature, reducing snowpack, and changing precipitation for water, energy, and food, as well as ecosystem processes at regional scales. Ecosystem services provide life support, goods, and natural resources from water, energy, and food, as well as the environments. There are knowledge gaps from the lack of conceptual framework and practices to interlink major climate change drivers of water resources with water-energy-food nexus and related ecosystem processes. This paper provided an overview of research background, developed a conceptual framework to bridge these knowledge gaps, summarized California case studies for practices in cross sector ecosystem services, and identified future research needs. In this conceptual framework, climate change drivers of changing temperature, snowpack, and precipitation are interlinked with life cycles in water, energy, food, and related key elements in ecosystem processes. Case studies in California indicated climate change affected variation in increasing temperature and changing hydrology at the regional scales. A large variation in average energy intensity values was also estimated from ground water and federal, state, and local water supplies both within each hydrological region and among the ten hydrological regions in California. The increased regional temperature, changes in snowpack and precipitation, and increased water stresses from drought can reduce ecosystem services and affect the water and energy nexus and agricultural food production, as well as fish and wildlife habitats in the Sacramento-San Joaquin Delta (Delta) and Central Valley watersheds. Regional decisions and practices in integrated management of water, energy, food, and related ecosystem processes are essential to adapt and mitigate global climate change impacts at the regional scales. Science and policy support for interdisciplinary research are critical to develop the database and tools for comprehensive analysis to fill knowledge gaps and address ecosystem service complexity, the related natural resource investment, and integrated planning needs.

An evaluation of HVAC energy usage and occupant comfort in religious facilities

To date, religious facilities have received little attention in the published literature regarding energy use and efficiency. With unique operating and building characteristics, these buildings have distinct opportunities for analysis in regards to building energy use and occupant comfort. With overall lower average energy intensity, religious facilities rarely receive energy assessments or are operated by experienced personnel. Therefore, identifying common issues is critical for training church owners in energy efficiency. This paper presents an in-depth analysis of heating, ventilation and air conditioning (HVAC) systems and occupant comfort in two religious facilities. The analysis reveals that the largest opportunities for reduction in energy use come from proper maintenance and operation of HVAC equipment and schedules. Temperature setbacks are shown to be an important operational setting to reduce energy usage. An accompanying analysis on thermal comfort reveals that temperature setbacks must be coupled with sufficient preconditioning of the space to ensure occupant comfort during intermittent building occupancy. An analysis of CO2 levels in the building during occupancy reveals the need for sufficient outside air to meet ventilation standards.

A Study of Energy Intensity and Carbon Intensity from Olefin Plants in Thailand

This research is aimed to estimate energy consumption and the greenhouse gases emission from olefins production process in Thailand and to analysis its correlation between energy intensity and carbon intensity. The results of five olefin case study plants showed that direct energy use of olefins production was about 87% of total energy consumption. The greatest amount of energy demand was supplied for fuel combustion in manufacturing processes. The olefin plants using gas feedstock could operate with less amount of energy consumed as the average energy intensity (EI) of 23.88 GJ/ton of olefin produced, whereas plants of olefin produced from steam cracking of liquid feedstock had the average EI of 33.21 GJ/ton of olefin produced. Greenhouse gas emission from olefin plants using gas feedstock were consistent with the result of EI. The carbon intensity (CI) from olefin plants using gas feedstock (0.98 tCO 2 -eq./ton of olefin produced) was lower than the plants using liquid feedstock (2.01 tCO 2 -eq./ton of olefin produced). The T-test function used to reflect the correlation between EI and CI emphasized that the carbon intensity was significantly correlated with the intensity of energy (r = 0.9564 and p = 0.05).

An Analysis of Energy and Carbon Intensities and Exergy Efficiency in Natural Gas Combined-Cycle Power Plants: A Case Study of Thailand

The objectives of this study were to estimate energy and carbon intensities of natural gas combined-cycle power plants and to improve the energy efficiency of power plants through an exergy analysis. Three plants in Thailand were evaluated as case studies in this research using data collected in 2013 – 2014. The results showed that the average carbon and energy intensities of three Combined-Cycle Power Plants were 0.436 kg CO 2 /kWh and 7.995 GJ/MWh, respectively. The range of the energy intensity in this study was slightly lower than that of other studies; however, the results of the carbon intensity were in the same range. The result of the exergy analysis illustrated that Heat Recovery Steam generator (HRSG) has the greatest exergy destruction due to the wide temperature range. To summarize, natural gas combined-cycle power plants require less energy and emit less carbon compared to other technologies or fuels. The exergy efficiency of HRSG was 60%, with an exergy destruction rate of 66.88 MW. One approach to improve the efficiency of power plants is to improve the efficiency and performance of HRSG.

Energy and carbon footprints of sewage treatment methods

The paper presents energy and carbon footprints of sewage treatment plants (STPs) operating at different scales and using different technology options based on primary data from 50 STPs operating in India and the UK. The study used a combination of fundamental mass-balance approach for energy consumption and the methodology defined by IPCC for the carbon emissions. Small-scale institutional STPs consume twelve times the energy consumed by large-scale municipal STPs, the corresponding energy intensities being 4.87 kWh/m3 and 0.40 kWh/m3 respectively. Embodied energy from construction material and chemicals accounted for 46% and 33% of the total energy intensity of the municipal and institutional STPs respectively. The average carbon footprint of large-scale STPs is 0.78 kgCO2eq/m3 and for small-scale STPs it is 3.04 kgCO2eq/m3. However, fugitive emissions from large-scale STPs constituted 74% of the total carbon emissions whereas the figure was only 0.05% for small-scale STPs. Average electrical energy intensity in STPs in India is much lower (0.14 kWh/m3) than that in the UK (0.46 kWh/m3). This is due to the reason that STPs in India do not have resource recovery processes and use solar heat for sludge drying. The paper offers information and insights for designing low carbon strategies for urban waste infrastructure.

CO2 mitigation potential in China's building construction industry: A comparison of energy performance

Building construction is a leading industry in China's economy and is also important in the fight against climate change mitigation. This paper fills the research gap by investigating the relationship between CO2 mitigation potential and energy performance in the building construction industry using a counterfactual analysis approach. A commonly used method is adopted to calculate energy-related CO2 emissions in the building construction industry and a newly proposed total-factor non-radial directional distance function is conducted to calculate energy performance. Further, they are connected through a logarithmic mean Divisia index decomposition analysis. The empirical results show that: (i) CO2 emissions in China's building construction industry are increasing rapidly and electricity consumption has become the main source of emissions. (ii) Energy intensity decline is the major contributor to CO2 mitigation. (iii) There exists a large room for energy intensity decline and more than 10% of the CO2 emissions could be reduced if the average energy intensity could achieve the level of the best performing provinces. (iv) The coastal regions show better energy performance than the interior regions and there is a significant tendency towards divergence of energy performance among provinces. It is thus necessary to encourage technology diffusion and mandate minimum energy performance standards.

Canadian Oil Sand Extraction: The Nexus between Economic Development and Environmental Sustainability

This paper investigates the relationship between environmental degradation, income and regulation for the Alberta province of Canada. This issue assumes a value added since Alberta is the third-largest oil reserve in the world after Saudi-Arabia and Venezuela. The province is interested by large extractions of unconventional oil from bituminous sands, which produces high greenhouse gas emissions (CO2, CH4, N2O and HFC). Our attention is focused on the environmental overexploitation, specifically air quality depletion, related to the oil sands extraction processes first and then on the level of GHG of the province. The paper has the following results: i) We provide a first assessment of the levels and the growth rates for GHG specifically generated by Alberta oil sands extraction, while distinguishing between in situ and mining extraction method. ii) We find a positive and strong relationship between economic growth and air degradation for the Alberta region during the last decade, discussing the issue in light of EKC literature. In this context we are not aware of other contribution addressing this question. iii) Our analysis highlights that the average energy intensity indicator of Alberta is higher by 11% then overall Canada, which is among countries with highest energy intensity. iv) The paper, next, propose an original indicator where we frame the relationship between GDP and GHG in a global view. We construct the Sustainable Income Index for Alberta and some selected countries relevant for our investigation. v) Eventually the paper discusses results in light of the possible regulation issues in the framework of International Panel for Climate Change (IPCC) guidelines and Kyoto Protocol.

The impact of scale on energy intensity in freight transportation

This paper analyzes energy intensities of ships, diesel–fuelled railways, trucks, and aircraft, using publicly available data. The analysis suggests that differences in operation, not technology, explain most of the variation in energy intensity within and across modes. Among the operational characteristics, most important is the amount of cargo weight transported per vehicle and therefore the scale of the respective transportation system. It is found that each mode has a characteristic envelope in an average energy intensity versus average cargo weight diagram, and estimates of the elasticities of energy intensity with respect to load size are made.

Estimating nonprocess energy from building energy consumption

From this research, an important technique for estimating the nonprocess energy (also known as overhead energy) in industrial and manufacturing buildings was examined. The building energy data for six industrial facilities were collected over multiple months in which production varied over these months. This technique then used a regression of monthly building energy or utilities' use versus monthly production rate. The nonprocess energy was estimated for each facility as the energy extrapolated to zero production in these regression models. The range of monthly production data was also used to determine a midpoint or average production at each facility and the corresponding average total building energy (process and nonprocess). The energy at zero production, as a percentage of the midpoint production energy, was thus the nonprocess energy percentage. In addition, the zero production power intensity (in watts per square meter) was compared to industry average nonprocess energy intensities (heating, cooling, lighting, and ventilation) to interpret the nature and possible improvement in nonprocess energy.