Increased Energy Use Research Articles

European Union legislation for demand-side management and public policies for demand response

Energy is now intrinsically linked to technological and social development, powering all such systems. The use of fossil fuels to supply the required energy is causing global environmental and health issues and is impacting on all life forms on the planet. Given the increasing energy use, anthropogenic greenhouse gas emissions are consequentially increasing. A critical and evolutionary way of thinking about the energy and resources demand management and supply is necessary because there is a clear concern about irreversible impacts on the world and a scarcity of the resources as well. At the same time, all the energy and resource use processes should be optimized to maximize the benefits, reduce the costs and promote stakeholders network, toward a circular economy. This could be the way to supply the demand without increasing the scarcity of the resources and to simultaneously achieve environmental benefits. At the same time, creating an educational grid is important to change the established paradigms, to promote critical thinking about the wasted resources and thinking holistically about overall consumption. This paradigm shift is changing the market, making it more competitive and reducing inefficiency by promoting the efficient use of resources. In the XXI century, legislation and public policies which consider sustainability approaches are constantly improving, trying to fix the pathways to avoid climate changes and achieve energy efficiency, but at the same time, the energy and resources demand still increasing to a no sustainable way to the social and environmental aspects.

Potential Changes in Greenhouse Gas Emissions from Refrigerated Supply Chain Introduction in a Developing Food System.

Refrigeration transforms developing food systems, changing the dynamics of production and consumption. This study models the introduction of an integrated refrigerated supply chain, or "cold chain," into sub-Saharan Africa and estimates changes in preretail greenhouse gas (GHG) emissions if the cold chain develops similarly to North America or Europe. Refrigeration presents an important and understudied trade-off: the ability to reduce food losses and their associated environmental impacts, but increasing energy use and creating GHG emissions. It is estimated that postharvest emissions added from cold chain operation are larger than food loss emissions avoided, by 10% in the North American scenario and 2% in the European scenario. The cold chain also enables changes in agricultural production and diets. Connected agricultural production changes decrease emissions, while dietary shifts facilitated by refrigeration may increase emissions. These system-wide changes brought about by the cold chain may increase the embodied emissions of food supplied to retail by 10% or decrease them by 15%, depending on the scenario.

How energy consumption is related to agricultural growth and export: An econometric analysis on Iranian data

Abstract Iranian agriculture has been supported by cheap energy for decades. So the question of whether this policy had brought any real outcome in terms of sector growth and export is of high importance for policy making. This paper tries to empirically identify such relation by using time series econometrics techniques including causality and cointegration tests for the period 1967–2015. Main results confirm existence of a unidirectional causality from energy consumption to agricultural growth while no relation is found between energy consumption and export. Other findings revealed that one percent increase in energy use results in 1.29 percent rise in agricultural growth in the long-run. In order to avoid detrimental impacts on sector growth, gradual liberalization of energy price for agricultural uses is recommended.

Assessment of water and energy use at process level in the U.S. beef packing industry: Case study in a typical U.S. large‐size plant

AbstractFood processing industries consume intensive water and energy to produce food products. However, their water and energy data are scarce and require for good measurement approaches. This study presents data collection and analysis of process‐level water and energy use in a large‐size U.S. beef packing plant through a combined use of portable and in‐line meters and theoretical calculations. The kill floor and plant cleaning are the primary water users, accounting for 28.7 and 24.0%, respectively. The refrigeration compressor system is the largest user of electricity, consuming 24.5% of plant‐wide electricity. Heating of water for plant cleaning and food safety purposes is the largest thermal energy use in summer (81%) and second‐largest in winter (49.7%), with unit heating values of 625 and 666 MJ/ton live cattle weight in the summer and winter, respectively. Twice as much thermal energy is used in the winter than summer due to space heating requirements. A regression analysis found that as outdoor temperatures increased, a slight water use increase and larger energy use decrease were observed.Practical applicationsCurrently available data on water and energy use in the U.S. beef packing industry are scarce, thus limiting the ability to develop new water and energy efficient technologies and policies based on an understanding of the current baseline operations. The current study conducts a detailed assessment of water and energy use at process level to enhance the understanding of the food‐energy‐water nexus in the beef processing industry, where limited data are available. Engineers can apply this case study as an example to share with their clients seeking to collect and analyze data with the goal of identifying water and energy conservation approaches. These results will inform beef processing researchers as they design novel technologies with that may result in improved water and energy efficiencies.

A theoretical study on a coupled effect of building envelope solar properties and thermal transmittance on the thermal response of an office cell

In recent decades, high level of urbanization, air pollution and climate change have caused a frequent occurrence of urban heat islands, resulting in thermal discomfort and increased energy use of buildings. As a response, a lot of attention has been paid to building envelope characteristics, with an increasing number of studies investigating building envelope solar properties as one of the important factors affecting thermal performance. However, different climate characteristics are the reason why solar properties may have different efficiency at various locations, also because in cold or temperate climates building envelope has to be more thermally insulated, namely having lower thermal transmittance. Therefore, within this study, building energy use and indoor thermal conditions were analysed for an office cell using different types of solar absorptivity (e.g. white, dark grey, collector or cool coating) and thermal transmittance, on either external wall or roof. The analysis was conducted for hot-arid and temperate climate locations. The results showed that solar absorptivity can have a significant effect on total energy use, especially in cases with higher envelope thermal transmittance. It also showed that the application of cool coatings is more reasonable if the external building envelope is not intensively thermally insulated (e.g. in hot-arid climate). In general, the optimal total energy use in both analysed climates was always achieved by implementing cool coatings. Furthermore, the results showed that white and cool coatings have comparable external (20–30 K above Tair in summer) and internal surface temperature responses, while dark grey coatings cause the surface to heat up significantly (external surface 60 K above Tair in summer).

Microalgae as Sustainable Energy and Its Cultivation

Growth of every country is depended on the ability to supply energy as per demand. Weather we notice it or not, the fact is energy is important in our daily life. The predicted expansion of world’s population is at least 9 billion by 2050, correlates increase of energy use globally to 812 quadrillion (1015) kJ by 2035 from 533 quadrillion kJ in 2008. A key challenge is to meet the growing demand for energy in a safe and environmentally responsible manner. Sustainable energy serves the needs of the present without compromising the ability of future generations to meet their needs. Technologies that promote sustainable energy include renewable energy sources, and bioenergy is one of the types of renewable energy. Bioenergy is any organic material which can store sun light in the form of chemical energy. Algal biofuel has a potential to reduce the demand of fossil fuels for energy requirements. Algae production do not have a stringent requirement of environmental conditions and can be produced in aqueous suspensions where sufficient light and carbon dioxide is available. Biofuels from algae have a high lipid density (15-300 times higher than traditional crops) as compared with other terrestrial crops. Algae have a harvesting cycle of 1–10 days. The amount of biomass is doubled typically within 24 hours under optimal growth conditions (enough nutrients, sunlight etc.). The two major bioreactor classes of algae growth systems are open ponds and closed reactors. The most common growth systems used for commercial purposes are open pond. Open ponds are relatively inexpensive compared to closed photo bioreactor. Algae cells are sensitive to hydrodynamic stress. The concept of cell damage correlates interaction between free cells and isotropic turbulence eddies based on Kolmogorov’s theory. When the micro-eddies size is close to the cell dimension, cell damage is higher; therefore, one should adjust the fluid flow in the open pond to maintain length of micro-eddies larger than the cell size. In the present investigation CFD code was used to study shear stress in open pond with side entry axial flow impeller. Three different channel lengths to width ratio were investigated with respect to size of micro eddies and shear stress.

Digital Acceleration of Sustainability Transition: The Paradox of Push Impacts

Sustainability requires ongoing reform of resource production and consumption to reduce environmental harms. The main way that Information and Communication Technology (ICT) can address these resource impacts is through digital optimization. Spreng found that optimization of an industrial process either increases energy use or accelerates production or consumption. It was assumed that reducing energy use progresses sustainability, whilst accelerating production or consumption to meet market demand is consumerist and generally detrimental to sustainability. In this paper, we argue that there are two important cases in which accelerating economic processes actually has an essential role in enabling sustainability by ICT: (1) when the process drives the production and adoption of an environmentally beneficial product such as a solar panel, often referred to as “cleantech”, or (2) when the process being increased is specific to the Circular Economy, such as recycling, maintenance/refurbishment, and sharing/reuse e.g., car-sharing, ride-sharing and tool-sharing in the Sharing Economy. The opportunities for ICT4S optimization are thus threefold: not just saving resources with efficiency, but also pushing the adoption of cleantech, and pushing the circulation of resources.

Body size shifts influence effects of increasing temperatures on ectotherm metabolism

AbstractAimWarmer temperatures directly increase metabolic rates of ectotherms, but temperature also indirectly affects metabolic rates. Higher temperatures result in smaller body sizes and associated decreases in metabolic rates, and it remains unknown whether this indirect effect of temperature increase could mitigate the direct positive effect of temperature on metabolic rate. Here, we assess whether temperature‐induced shifts in body size are likely to offset the direct influence of temperature on metabolic rate.LocationGlobal.Time period1940–2011.Major taxa studiedEctotherms.MethodsWe compiled literature‐derived data on mass and temperature for 109 ectotherm species raised at various constant temperatures. Using an allometric equation to estimate metabolic rate from size and temperature, we determined the body masses necessary for species to maintain constant metabolic rates under increased temperatures. We also calculated and compared (a) change in metabolic rate attributable to increased temperature where body size does not change with (b) change in metabolic rate including empirical size change.ResultsWarmer temperatures resulted in increased metabolic rate estimates, but this was partly offset by decreased body sizes for the majority of species. For most species, observed decreases in body size at higher temperatures were insufficient to avoid metabolic rate increases.Main conclusionsAlthough the indirect effect of temperature on metabolic rate via body size is not sufficient to counterbalance the direct effect, it limits the magnitude of the increase in metabolic rate. Thus, in a warming climate, ectotherms are likely to experience increases in energy use that are smaller than anticipated. Given that metabolic rates have substantial, diverse impacts on individuals, populations, and ecosystems, these indirect effects of temperature change will have complex cascading effects on ecological communities, but the impacts of increases in metabolic rate of these varying magnitudes are unknown.

Importance of considering environmental sustainability in dietary guidelines

Importance of considering environmental sustainability in dietary guidelines

Energy use and height in office buildings

ABSTRACTThe relationship between energy use and height is examined for a sample of 611 office buildings in England and Wales using actual annual metered consumption of electricity and fossil fuels. The buildings are of different ages; they have different construction characteristics and methods of heating and ventilation; and they include both public and commercial offices. When rising from five storeys and below to 21 storeys and above, the mean intensity of electricity and fossil fuel use increases by 137% and 42% respectively, and mean carbon emissions are more than doubled. A multivariate regression model is used to interpret the contributions of building characteristics and other factors to this result. Air-conditioning is important, but a trend of increased energy use with height is also found in naturally ventilated buildings. Newer buildings are not in general more efficient: the intensity of electricity use is greater in offices built in recent decades, without a compensating decrease in fossil fuel use. The evidence suggests it is likely – although not proven – that much of the increase in energy use with height is due to the greater exposure of taller buildings to lower temperatures, stronger winds and more solar gains.

Production efficiency, costs and environmental impacts of conventional and dynamic forage systems for dairy farms in Italy

Abstract Over the last few decades, scientists, decision-makers, consumers and the more volatile marketplace impose to dairy farms to manage forage systems more sustainably, while maintaining profitability. Hence, shifting from a conventional forage system based mainly on monocropping corn (CONV_FS) to a more flexible one, defined as dynamic forage system (DYN_FS), that is based on increasing on-farm cropping of leguminous species, double cropping, scheduling of forage cuts to early stages of growth, and the adoption of silage conservation in place of haymaking, could help increasing overall system sustainability. A multi-year study, conducted on two commercial high productive dairy farms, analyzed this shift from an agronomic, economic and environmental point of view. The two farms milked 127 and 262 cows, farmed 56 and 102 ha, and had a milk production intensity of 20 and 26 t/ha per year, respectively. All the data necessary to determine dry matter (DM) yield, forage quality, in terms of crude protein (CP) and metabolizable energy (ME), the nitrogen balance, agrochemical management, the energy balance and efficiency, labor use, economic budgets, and carbon footprint of the two forage systems were on farm measured and collected. One hectare of tillable land, 1 t of DM or CP, and 1 GJ of ME were chosen as functional units. The adoption of DYN_FS increased overall system efficiency (increased DM, CP and ME yields per hectare), reduced reliance on external inputs (chemical N and pesticides), led to a more equilibrated N balance, reduced agrochemical use intensity and potential ecotoxicological impacts, increased energy use efficiency and reduced carbon footprint when compared to CONV_FS. Shifting from DYN_FS to CONV_FS had also a positive effect on the costs sustained per hectare of tillable land, whereas the labor requirements increased slightly on a per hectare basis, but decreased relative to the chosen functional units. Finally, DYN_FS provided more ME and CP than CONV_FS, but maintained a similar milk production and quality. We have concluded that the new dynamic forage system DYN_FS has the potential of being profitable and could enhance production efficiency and environmental quality in the more intensive forage systems adopted on dairy farms in the Po plain in Italy.

Stakeholder Specific Multi-Scale Spatial Representation of Urban Building-Stocks

Urban building-stocks use a significant amount of resources and energy. At the same time, they have a large potential for energy efficiency measures (EEM). To support decision-making and planning, spatial building-stock models are used to examine the current state and future development of urban building-stocks. While these models normally focus on specific cities, generic and broad stakeholder groups such as planners and policy makers are often targeted. Consequently, the visualization and communication of results are not tailored to these stakeholders. The aim of this paper is to explore the possibilities of mapping and representing energy use of urban building-stocks at different levels of aggregation and spatial distributions, to communicate with specific stakeholders involved in the urban development process. This paper uses a differentiated building-stock description based on building-specific data and measured energy use from energy performance certificates for multi-family buildings (MFB) in the city of Gothenburg. The building-stock description treats every building as unique, allowing results to be provided at any level of aggregation to suit the needs of the specific stakeholders involved. Calculated energy use of the existing stock is within 10% of the measured energy use. The potential for EEM in the existing stock is negated by the increased energy use due to new construction until 2035, using a development scenario based on current renovation rates and planned developments. Visualizations of the current energy use of the stock as well as the impact of renovation and new construction are provided, targeting specific local stakeholders.

The Effect of Tree Plantations on Moderating Air Temperature in Arafat, Makkah for the Period 2002-2016

Recently many studies have shown that average temperature has increased globally. However, temperature trends vary in different parts of the world due to local geographical, climatic, land usage and various socio-economic factors. This study focuses on temperature trend in Makkah and intends to investigate the effect of vegetations on temperature trend. Temperature trend is analyzed from two meteorological monitoring sties in Arafat and Waly Al-Ahd area for the period 2002-2016. The two sites have demonstrated opposite trends from each other for the above period. In Arafat area temperature has not increased and has rather decreased during the last 15 years (-0.05oC/year). The negative trend in Arafat was more evident since 2009 (-0.21oC/year). In contrast, Waly Al-Ahd area demonstrated positive significant trend (+0.14oC/year). In Arafat area mass tree plantation has taken place during the last couple of decades. Furthermore, Arafat has experienced no urbanization, as it is one of those Holy areas that are reserved for the purpose of Hajj. During the study period greenery in Arafat area has increased significantly since the plantation project was started in 1986. In contrast rapid urbanization, resulting in increase in energy use, road traffic, and change in land usage has led to temperature rise in most parts of the Makkah City including Waly Al-Ahd. This study shows how local factors, such as vegetation can affect local temperature trend. Arafat tree plantation project can be used as a good example to encourage more tree plantation in the Holy sites to cope with the increasing heat in the coming decades. Trees also provide shelter from the blazing sun, especially during Hajj season in Makkah, where temperature reaches as high as 50oC in summer months and probably will continue to rise in the future.

A Study on Daegu City Citizen’s Consciousness about Urban Green Space for Heat Wave Mitigation

Daegu City has the most number of heat waves every year in the last 10 years among 7 metropolitan cities in Korea. As the slang, such as ‘Daefrica(Daegu + Africa)’ shown, Daegu City is recognized as a high temperature region in the summer. The purpose of this study is to understand the perception of urban green space as a mediator for heat wave mitigation for Daegu citizens. First, about 93.3% of the respondents perceived what the heat was. The most frequent cause of the increase in the number of heat waves was the increase in energy use (34.9%), ‘indiscriminate development’ (24.9%), ‘automobile and traffic increase’ (17.9%), ‘greenery reduction’ (12.6% ) were the most common cause. Second, 87.1% of respondents had positive perception about the mitigation effect on the effect of urban green space as a medium to mitigate the heat. In addition, 26.7% of respondents answered that they are very effective in mitigating the effect of the heat of urban greenery, and 95.1% of them responded more than ‘normal’. Third, as a result of examining the priorities of short and long-term heat-related policies, the short term was the highest (37.5%) in responding to ‘electricity tariff realization’ because of the high dependence on air conditioners. In contrast to the short-term perspective, the long-term policy for mitigating the heat wave was overwhelmingly supported by ‘expansion of urban green areas’ (50.7%). This is a result of confirming Daegu citizens’ consciousness which is highly evaluating the effect of urban green space as a medium for mitigating the heat. Fourth, the importance and performance of ‘urban green space type’ for mitigation of the heat wave were examined. The type of urban green space belonging to the phenomena maintenance area (quadrant Ⅰ), which both had high importance and performance, was classified as ‘neighborhood park’. In addition, it was surveyed as ‘Ssamji(mini) Park’ as the type of urban greenery in the concentrated improvement area (quadrant Ⅱ) where the importance is high but the performance is low. We believe that the value of urban green areas for mitigating the heat waves has been fully recognized through the recognition of Daegu citizens. We hope that the results of this study will be used as basic data for future Daegu city heat and urban greening policy.

Energy Use and Perceived Indoor Environment in a Swedish Multifamily Building before and after Major Renovation

Improved energy efficiency in the building sector is a central goal in the European Union and renovation of buildings can significantly improve both energy efficiency and indoor environment. This paper studies the perception of indoor environment, modelled indoor climate and heat demand in a building before and after major renovation. The building was constructed in 1961 and renovated in 2014. Insulation of the façade and attic and new windows reduced average U-value from 0.54 to 0.29 W/m2·K. A supply and exhaust ventilation system with heat recovery replaced the old exhaust ventilation. Heat demand was reduced by 44% and maximum supplied heating power was reduced by 38.5%. An on-site questionnaire indicates that perceived thermal comfort improved after the renovation, and the predicted percentage dissatisfied is reduced from 23% to 14% during the heating season. Overall experience with indoor environment is improved. A sensitivity analysis indicates that there is a compromise between thermal comfort and energy use in relation to window solar heat gain, internal heat generation and indoor temperature set point. Higher heat gains, although reducing energy use, can cause problems with high indoor temperatures, and higher indoor temperature might increase thermal comfort during heating season but significantly increases energy use.

Assessing the nearly zero-energy building gap in university campuses with a feature extraction methodology applied to a case study in Spain

Public universities face the challenge of retrofitting the actual campus buildings into nearly zero-energy buildings (NZEB). In this study, a novel methodology for evaluating historical energy use and renewable energy production for all the buildings of a university, including hourly, daily and monthly data assessments is presented. This analysis is useful as a baseline for comparisons with future energy retrofits and enables determining the current gap between actual energy indicators at building and campus levels and the established limits for NZEB non-residential buildings in the European Union. The methodology is applied to a case study at the University of Lleida, a typical average-size university in Spain. Results show a wide variation in energy use among campus buildings, ranging between 50 and 470 kWh/m2 year. Constant or slightly increasing energy use and decreasing trends in renewable energy generation are observed. The daily electricity profiles have shown similar patterns among buildings and substantial potential energy savings during unoccupied periods. In the NZEB analysis, the average non-renewable primary energy use is about 4 times higher than the maximum estimated Spanish threshold range of 45–55 kWh/m2 year. Deep energy renovation strategies are, thus, needed for universities to meet EU NZEB targets.

Evaluation of a feedback control method for hydronic heating systems based on indoor temperature measurements

Indoor temperatures in apartment blocks are often indirectly controlled by the outdoor temperature using a feedforward control loop, in which the radiator supply temperature is a function of the outdoor temperature. However, this control principle cannot take into account heat gains or losses caused by tenants, electrical appliances, the sun, air leakage, etc., which may result in uneven indoor temperatures, overheating, airing and increased energy use. This can be partly addressed by using thermostatic valves on each radiator. A municipal housing company in Sweden that uses individual metering and billing (IBM) of space heating costs based on measurements of indoor temperatures in all rooms of each apartment has been studied. This article presents and evaluates a project in which these measurements were used for feedback control. The aim of the study was to evaluate the principle which is based on using the actual indoor temperatures. An existing feedforward control of the heating system with thermostatic valves was enhanced by a correction of the supply temperature. The magnitude of the correction was proportional to the difference between the actual mean indoor temperature of the apartments and the set-point temperature. The enhanced control resulted in more constant indoor temperatures, i.e. they were less dependent on the outdoor temperature. The results support the conclusion that the evaluated method would be promising to apply in multi-family buildings. The introduction of the enhanced control method provided valuable experience and awareness of influencing factors if it were to be implemented on a larger scale.

The effect of industry delocalization on global energy use: A global sectoral perspective

Sectoral production technologies differ largely across countries, so do sectoral energy intensities. Hence, shifts in production locations within global sectors, possibly caused by environmental regulations, are likely to have an impact on aggregated energy usage and emissions. Applying a Logarithmic Mean Divisia Index decomposition we decompose changes of sectoral energy use from 2001–2011 into three effects: (sectoral) value added, energy efficiency and delocalization, which in this paper is conceived as a structural effect within sectors, between regions. Our results show that although economic activity and technological progress dominate global energy use developments, for most sectors a delocalization towards less efficient production places is ongoing. It contributes to annual increases in energy use in the range of 1–6%. Especially, manufacturing sectors, which are among the most energy consuming sectors, reveal significant increases in energy usage due to delocalization since 2004. This development is accompanied by declining energy intensity improvement rates, indicating that delocalization induces second order effects.

Diagnosis and Remodeling of an Aged Library Building for Zero-Energy Certification

Most of domestic buildings have been over 15 years since their construction. The aged buildings tend to deteriorate thermal performance of envelopes and increase energy use. Therefore, green remodeling is carried out to improve the thermal performance of the aged buildings. There were a number of cases conducted remodeling of an existing building to improve a building performance. However, it is rare to remodel an existing building to zero energy level. In addition, there is no analysis on effects and considerations for remodeling to zero energy building level, neither standard remodeling manual for references. Therefore, it is currently being remodeled based on the knowledge and experience of the contractor. This study reviewed diagnostic and remodeling plans to remodel buildings to zero energy levels and tried to assist in the production of standard remodeling manuals. A target building constructed in 2000 was selected, and this study implemented several energy-efficiency measures: passive, active, and renewable. As a result, this study achieved 1 ++ level of the “Building Energy Saving Design Standard” and achieved zero energy building level.

Two-Stage Integer Programing Model for Building Retrofit Planning for Energy Saving in South Korea

Due to the heightened concerns of global environmental problems caused by the heavy use of fossil fuels, the sharp increase of energy use in the building sector has been recognized as an important environmental issue. One solution for efficient energy consumption in the building sector is building retrofits. This study proposes a two-stage integer programing model to select building retrofit materials and retrofit planning. The first model is based on a multi-objective optimization that derives an optimal retrofit strategy considering both energy savings and retrofit costs. Using the results of the first model, the second model finds an optimal retrofit plan to minimize losses for the building owner. Based on a real general hospital building in Korea, a simplified case building was used to verify the proposed models and for experimental analyses. According to the results of the second model, the building owner could adopt a building retrofit with less than 30–40% of the initial budget when compared to the total retrofit costs.