Increased Energy Use Research Articles

A comparison of global bioclimates in the 20th and 21st centuries and building energy consumption implications

Summer and winter thermal discomforts in the major climate zones and sub-zones of the Köppen–Geiger world climate classifications during the 21st century were investigated and compared with those in the 20th century. Compared with the 20th century, frequency of distribution of the comfort index for the 21st century shows a distinct decrease in winter thermal discomfort and increase in summer thermal discomfort under the low and medium forcing emissions scenarios. Based on zone-average analysis, decreasing trends of cumulative cold stress and increasing trends of cumulative heat stress have been observed in all the major climate zones and sub-zones. There is an overall increase in energy use for space conditioning for all the sub-zones in equatorial climates, and an overall reduction in all the snow and polar climates sub-zones. In arid and warm temperate climates, the hot sub-zones have an increase in the overall energy requirements whereas the cold/warm sub-zones have a reduction. Locations within the hot summer sub-zones in warm temperate climates will become much more cooling-dominated, and there are significant increases in cumulative heat and proportional stresses in the hot summer sub-zones in snow climates. Implications for energy use and carbon emissions are discussed and mitigation/adaptation measures suggested.

Implementation of Brackish Groundwater Desalination Using Wind-Generated Electricity: A Case Study of the Energy-Water Nexus in Texas

Growing populations and periodic drought conditions have exacerbated water stress in many areas worldwide. In response, some municipalities have considered desalination of saline water as a freshwater supply. Unfortunately, desalination requires a sizeable energy investment. However, renewable energy technologies can be paired with desalination to mitigate concern over the environmental impacts of increased energy use. At the same time, desalination can be operated in an intermittent way to match the variable availability of renewable resources. Integrating wind power and brackish groundwater desalination generates a high-value product (drinking water) from low-value resources (saline water and wind power without storage). This paper presents a geographically-resolved performance and economic method that estimates the energy requirements and profitability of an integrated wind-powered reverse osmosis facility treating brackish groundwater. It is based on a model that incorporates prevailing natural and market conditions such as average wind speeds, total dissolved solids content, brackish well depth, desalination treatment capacity, capital and operation costs of wind and desalination facilities, brine disposal costs, and electricity and water prices into its calculation. The model is illustrated using conditions in Texas (where there are counties with significant co-location of wind and brackish water resources). Results from this case study indicate that integrating wind turbines and brackish water reverse osmosis (BWRO) systems is economically favorable in a few municipal locations in West Texas.

The Effects on Energy Saving from Taxes on Motor Fuels: The Swedish Case

The objective with this study is to analyze the role of energy taxes for energy efficiency in the Swedish transport sector. In particular we analyze how large share the Swedish energy tax will contribute to the overall Swedish target for energy efficiency set by the EU directive for energy efficiency. To obtain the objective a dynamic demand model for gasoline and diesel is estimated, based on Swedish time series data from 1976 to 2012. The results from the demand model shows that a higher tax on gasoline results in lower gasoline demand, but leads to an increase in diesel consumption, and vice versa. A removal of the energy and CO2 tax, lowering both the gasoline and diesel consumer price, leads to an overall increase in energy use, but also to an increase in the share for diesel in fuel use. Concerning energy savings the simulation results show that the current Swedish energy and CO2 taxes are sufficient for achieving the EU stipulated target, and hence no additional measures has to be taken.

The influence of South Korean energy policy on OPEC oil exports

South Korea is the fifth top oil importer worldwide with 64% of its oil coming from OPEC member countries. Over the last 30 years, South Korea accounted for a rapid increase in energy use. This in turn led South Korea to be totally dependent on oil imports. Due to this increase, South Korea has been experiencing drastic changes in its energy system which could potentially impact its dependence on OPEC oil import. External and internal factors have forced South Korea to change its energy strategy and targets. These targets would be achieved by reducing its energy intensity and utilizing electricity and renewable energies in order to reduce its dependence on oil consumption. “Low Carbon, Green Growth” is one policy along with many other energy policies developed by South Korea for reducing greenhouse gases, thus this policy is receiving a remarkable attention today. These national policies along with other international ones are needed to mitigate greenhouse gas emissions and promote other green initiatives. This study puts emphasis on these policies as well as uses them to predict the future energy profile of South Korea and how these policies will impact on oil imports from OPEC member countries.

Integration of the soybean production chain and biodiesel: an international parallel to the Brazilian biofuel

Increasing energy use, climate change and carbon dioxide (CO2) emissions from fossil fuels make switching to biofuels a high priority. Demand for biofuel, specifically based on biodiesel, should change the composition of Brazilian exportation of soybean agro-industrial system. Studies of agricultural chains have drawn attention to important roles including international and domestic market, international traders, the state and standards used extensively to examine a wide range of the commodities context. This paper examines a systemic overview of productive chain of soybean and biodiesel, in Brazil and worldwide, focuses on production and exportation contextualised in sustainable development, Brazilian legislation in comparison with European legislation and the consequences about them.

The effects of trade liberalization on environmental degradation

This paper uses a threshold model to estimate the regime-specific marginal effect of trade liberalization and other determinants of environmental degradation in regimes with different levels of corruption. The results show that increasing trade liberalization leads to an increase in carbon dioxide (\(\mathrm{{CO}_{2}}\)) emissions in countries with a high level of corruption but to an decrease in countries with low corruption. A U-shaped relationship between \(\mathrm{{CO}_{2}}\) emissions and income exists in low-corruption countries but not in high-corruption countries. Our results also show that an increase in energy use per $1,000 in gross domestic product and fossil-fuel energy consumption will increase \(\mathrm{{CO}_{2}}\) emissions in any country. Moreover, increases in agricultural value and foreign direct investment can decrease environmental degradation in any country.

Lumen Maintenance and Light Loss Factors: Consequences of Current Design Practices for LEDs

Light loss factors are used to help lighting systems meet quantitative design criteria throughout the life of the installation, but they also carry ancillary consequences, such as influencing first cost and energy use. As the type of light sources being specified continues to evolve, it is an appropriate time to evaluate the methods used in calculating light loss factors and understand the broad effects of performance attributes like lumen maintenance. Because of the unique operating characteristics of light emitting diodes (LEDs) and lack of a comprehensive lifetime rating—as well as the problematic relationship between lifetime and lumen maintenance—determining an appropriate lamp lumen depreciation (LLD) factor for LED products is difficult. The IES recommends using an LLD of not greater than 0.70 when quantity of light is an important design consideration. This approach deviates from the typical practice for conventional sources of using the ratio of mean to initial lumen output and may misrepresent actual performance, increase energy use, and inhibit comparisons between products. This article discusses the complications related to LLD and LEDs, compares the performance of some conventional and LED products, and examines alternatives to the current recommended approach for determining LLDs for LED products.

Development of green campus in China

Abstract The higher education is experiencing a rapid development in China, with the sharp increase of energy use and the low level of campus facility operation. Meanwhile, with the responsibility for knowledge transformation, sci-tech talents cultivation and technical innovation, universities are of great importance in the development of the sustainable society. The initiative of green campus has attracted great attention from both the society and the universities themselves. Therefore, it is very meaningful to get a full understanding of the current status of green campus development in China, and make the feasibility planning for the next step on this base. In this paper, the progress of green campus development in China is summarized, including all the initiatives to conduct the energy and resource efficient campus, and the current status of upgrading the energy and resource efficient campus to the green campus; the problems occurred during the development are analyzed, and the possible approaches and the action plan are explored accordingly, to promote the green campus development. It is found from the analysis that the development of energy and resource efficient campus has been expanded in a large scale in China, mainly aiming at the energy efficient technology application and campus energy management, and all these initiatives are strongly promoted by the national government with policy support and financial funding. With these great endeavors, an upgrade from the energy and resource efficient campus to the green campus is on progress, which expands its scope to sustainable education and the initiative of low-carbon life on campus. However, many problems also occurred during the progress, such as the lack of a good top-level design among different national ministries and the collaborative innovation among different departments in the university, and the need of a practical propulsion mode and a long-term mechanism to guarantee green campus development. Hence, some suggestions are made in terms of the administrative management, propulsion approach, evaluation standard, and action plan.

Exploring synergies and tradeoffs: Energy, water, and economic implications of water reuse in rice-based irrigation systems

Efficient use of water and energy resources are significant requirements for increasing irrigated rice productivity. However, the ever increasingly complex interplay between energy, water and agriculture in feeding both machinery and people, respectively, plus the added impact on and of climate change, have significant implications on the management of our natural resources. This paper holistically analysed a rice-dominated gravity-fed irrigation system using the Upper Pumpanga River Integrated Irrigation System (UPRIIS) in Central Luzon, the Philippines as demonstration example to quantify the water, energy and economic implications of water reuse at five different spatial scales. Water reuse was determined through daily measurements of all surface water inflows and outflows, rainfall, evapotranspiration, and the quantities of water internally reused through check dams and shallow pumping, and aggregated into seasonal totals for five spatial scales during the dry season of 2001. Energy auditing was later used to evaluate the energy implications of water reuse.Results show that ∼30% of the total surface water applied was reused by internal check dams and pumping from shallow groundwater. Across the five spatial scales, water productivity with water reuse was always higher than without water reuse, which reflects the significance of water reuse. The cost-benefit ratio indicates enhanced rice profitability at all five spatial scales with and without water reuse. However, economic benefits of water reuse were lower than economic benefits from surface water, which was mainly due to the higher costs of pumping. Irrigation requires a significant expenditure of fossil energy both for pumping and delivering water to crops. Total energy inputs of water reuse were 28% higher than the energy inputs without water reuse, which was mainly attributed to higher diesel energy inputs.Whilst water reuse contributes significantly to water productivity across the five spatial scales, it does increase energy use due to pumping. Our holistic analysis indicated a tradeoff between yield and energy use. Achieving higher water productivity would require additional use of fossil energy, which in turn could increase the energy use competition and decrease economic returns. Given the increasing global concerns about climate change and sustainable energy use, an optimal combination of water and energy use is absolutely essential.

Stoffliche versus energetische Nutzung von Holz – wohin geht die Reise? (Essay)

Material or energy use for wood: which way forward? (Essay) Wood as a renewable raw material plays an increasing role in the debate about developing renewable energies. Energy use of wood is often in competition with material use. In 2010, in Germany, for the first time more wood was used for energy than as raw material. Rising demand for energy wood is leading to steeply upward price trends for all wood assortments put on the market. In this respect, Germany is not alone. By 2020, in Europe the average share of renewable energies in primary energy consumption should reach 20%. Higher demand for wood biomass from European forests will pose major challenges for countries. One way of covering the rising demand for wood is imports from other continents. European energy companies are constructing pellet plants overseas and transporting the pellets to be burnt as biomass in Europe. In the final analysis, whether to follow the energy or the raw material path for wood in the medium to long term is a choice for society as a whole. However, increased energy use of wood does not necessarily lead to the elimination of traditional material uses. It can also be a bridge for new processes and products to enter the markets. Wood has much potential which has not yet been developed. A new definition of the value chain for wood offers the possibility to unite the ecological and economic approaches and brings the vision of a sustainable society one step nearer.

Urban residential energy use in Kandahar, Afghanistan

The paper presents an insight to the household energy consumption in urban Afghanistan, and is based on household surveys conducted in one of its growing cities – Kandahar. The analysis shows that the energy consumed in residential sector has the major share in the total energy consumed in urban Afghanistan. About 72% of the total residential energy is spent for cooking purposes, and firewood is still the predominant form of energy with a share of around 58% for different end uses. Details on current energy process and the energy expenditure for different income levels have been presented. Although the total energy consumption in urban household is relatively lower in Afghanistan, the paper argues that the increase in consumption and transition to modern fuels is likely with increased urbanization, socioeconomic development and improved electricity supply. Against the backdrop of likely increase in energy use, the issue of sustainability becomes significant and therefore, policies are key to ensuring energy development taking into consideration sustainability concerns.

Causality between energy and output in the long-run

Though there is a very large literature examining whether energy use Granger causes economic output or vice versa, it is fairly inconclusive. Almost all existing studies use relatively short time series, or panels with a relatively small time dimension. We apply Granger causality and cointegration techniques to a Swedish time series dataset spanning 150years to test whether increases in energy use and energy quality have driven economic growth or vice versa. We show that these techniques are very sensitive to variable definition, choice of additional variables in the model, sample periods and size, and the introduction of structural breaks. The relationship between energy and growth may also have changed over time – energy causes output in the full sample while output causes energy use in recent smaller samples. Energy prices have a more robust causal impact on both energy use and output.

Energy use, exports, imports and GDP: New evidence from the OECD countries

This paper aims to investigate the relationship between energy use-GDP, energy use-exports-trade and energy use-imports on aggregate level in the OECD countries. While the energy use-growth nexus is widely examined in the literature, studies on the energy use-trade nexus are very scarce. Thus, this study also serves to fill this gap by presenting a new research on the OECD countries. We employ the panel cointegration technique and use the Granger representation theorem to examine the presence of long-run relationship and the causality between pairs of variables. To investigate the presence of causality, several tests developed by Canning and Pedroni (2008) are used. We find that the pairs of energy use-GDP, energy use-exports and energy use-imports are cointegrated and there is two-way Granger causality between each pairs. We also estimate the long-run elasticities by employing panel dynamic ordinary least squares. The results suggest that the sign of long-run elasticity is positive for all pairs. Particularly, 1% increase in GDP, export and import causes almost 0.32%, 0.21% and 0.16% increase in energy use respectively.

Lactating Ctcgrp Nulls Lose Twice the Normal Bone Mineral Content due to Fewer Osteoblasts and More Osteoclasts, Whereas Bone Mass Is Fully Restored After Weaning in Association With Up-Regulation of Wnt Signaling and Other Novel Genes

The maternal skeleton resorbs during lactation to provide calcium to milk and the lost mineral content is restored after weaning. The changes are particularly marked in Ctcgrp null mice, which lose 50% of spine mineral content during lactation but restore it fully. The known calciotropic hormones are not required for skeletal recovery to occur; therefore, unknown factors that stimulate bone formation may be responsible. We hypothesized that the genes responsible for regulating postweaning bone formation are differentially regulated in bone or marrow, and this regulation may be more marked in Ctcgrp null mice. We confirmed that Ctcgrp null mice had twice as many osteoclasts and 30-40% fewer osteoblasts as compared with wild-type mice during lactation but no deficit in osteoblast numbers after weaning. Genome-wide microarray analyses on tibial RNA showed differential expression of 729 genes in wild-type mice at day 7 after weaning vs prepregnancy, whereas the same comparison in Ctcgrp null mice revealed only 283 genes. Down-regulation of Wnt family inhibitors, Sost and Dkk1, and inhibition of Mef2c, a sclerostin stimulator, were observed. Ctsk, a gene expressed during osteoclast differentiation, and Igfbp2, which stimulates bone resorption, were inhibited. Differential regulation of genes involved in energy use was compatible with a net increase in bone formation. The most marked changes occurred in genes not previously associated with bone metabolism. In conclusion, the postlactation skeleton shows dynamic activity with more than 700 genes differentially expressed. Some of these genes are likely to promote bone formation during postweaning by stimulating the proliferation and activity of osteoblasts, inhibiting osteoclasts, and increasing energy use.

Modelling HGV freight transport energy demand in Ireland and the impacts of the property construction bubble

Freight transport is both significant and fast growing in terms of energy use but there are few papers that focus on modelling future freight transport energy use. This paper addresses this knowledge gap, focussing on Ireland, which is an interesting case study because it has witnessed a significant increase in energy use for freight from 1990 to 2007 followed by a dramatic drop in the following two years due to the property construction bubble bursting and economic recession. The paper focuses on HGV freight only due to gaps in LGV data and the focus on construction activity. We disaggregate freight activity (tkm) in terms of three commodity groupings (reflecting sectoral activity) and weight class, and estimate historical HGV energy demand by commodity group using specific energy consumption (MJ/tkm) by weight class. We then determine the most significant economic driver behind the activity trends for each commodity grouping and the associated elasticity of demand. Finally we use these elasticities along with national economic forecasts to project future HGV activity and energy for each commodity grouping. Comparing the approach presented with an aggregated GDP-tkm-MJ approach, it is clear from the results that the disaggregated approach captures better the trend in the period 2008–2010.

Causality Between Energy and Output in the Long-Run

Though there is a very large literature examining whether energy use Granger causes economic output or vice versa this literature is fairly inconclusive. Almost all existing studies use relatively short time series or panels with a relatively small time dimension. Additionally, many recent papers continue to use what seem to be misspecified models. We apply Granger causality and cointegration techniques to a Swedish time series data set on energy and economic growth spanning 150 years to test whether increases in energy use and energy quality have driven economic growth. We show that these techniques are very sensitive to variable definition, choice of additional variables in the model, and sample periods. All of the following appear to make a finding that energy causes growth more likely: using multivariate models, defining variables to better reflect their theoretical definition, using larger samples, and including appropriate structural breaks. However, it is also possible that the relationship between energy and growth has changed over time and that results from recent smaller samples reflect this. Energy prices have a significant causal impact on both energy use and output.

Life cycle analysis of geothermal power generation with supercritical carbon dioxide

Life cycle analysis methods were employed to model the greenhouse gas emissions and fossil energy consumption associated with geothermal power production when supercritical carbon dioxide (scCO2) is used instead of saline geofluids to recover heat from below ground. Since a significant amount of scCO2 is sequestered below ground in the process, a constant supply is required. We therefore combined the scCO2 geothermal power plant with an upstream coal power plant that captured a portion of its CO2 emissions, compressed it to scCO2, and transported the scCO2 by pipeline to the geothermal power plant. Emissions and energy consumption from all operations spanning coal mining and plant construction through power production were considered, including increases in coal use to meet steam demand for the carbon capture. The results indicated that the electricity produced by the geothermal plant more than balanced the increase in energy use resulting from carbon capture at the coal power plant. The effective heat rate (BTU coal per total kW h of electricity generated, coal plus geothermal) was comparable to that of traditional coal, but the ratio of life cycle emissions from the combined system to that of traditional coal was 15% when 90% carbon capture efficiency was assumed and when leakage from the surface was neglected. Contributions from surface leakage were estimated with a simple model for several hypothetical surface leakage rates.

Study and determination of energy consumption to produce conventional rice of the Guilan province

The aim of this study was to determine the energy efficiency indices in the agro-ecosystems of the Guilan province in 2010. One hundred and twenty-seven farmers were interviewed using a particularly designed questionnaire. The inputs in the calculation of energy use in agro-ecosystems embraced labour, machinery, electricity, diesel oil, fertilizers, seeds, while rice and straw yield were included in the output. The results depicted that total input and output energy into these agro-ecosystems were about 47,604 and 90,680.04 MJ/ha, respectively. The highest energy input was related to water (38.84%), electricity (27.87%) and nitrogen fertilizer (17.5%). Energy efficiency and energy productivity in these agro-ecosystems was 2.19 and 0.064 kg/MJ, respectively, and water productivity was 0.11 kg/m<sup>3</sup>. The results also showed that due to application of flood irrigation in these agro-ecosystems and also water elicited from subterranean sources by electrical pump, the inputs had the largest portion among the energy inputs to agro-ecosystems that this matter increased energy use in the unit area and also reduced energy efficiency and productivity.

Glycogen, not dehydration or lipids, limits winter survival of side-blotched lizards (Uta stansburiana)

Climate change is causing winters to become milder (less cold and shorter). Recent studies of overwintering ectotherms have suggested that warmer winters increase metabolism and decrease winter survival and subsequent fecundity. Energetic constraints (insufficient energy stores) have been hypothesized as the cause of winter mortality but have not been tested explicitly. Thus, alternative sources of mortality, such as winter dehydration, cannot be ruled out. By employing an experimental design that compared the energetics and water content of lizards that died naturally during laboratory winter with those that survived up to the same point but were then sacrificed, we attempt to distinguish among multiple possible causes of mortality. We test the hypothesis that mortality is caused by insufficient energy stores in the liver, abdominal fat bodies, tail or carcass or through excessive water loss. We found that lizards that died naturally had marginally greater mass loss, lower water content, and less liver glycogen remaining than living animals sampled at the same time. Periodically moistening air during winter reduced water loss, but this did not affect survival, calling into question dehydration as a cause of death. Rather, our results implicate energy limitations in the form of liver glycogen, but not lipids, as the primary cause of mortality in overwintering lizards. When viewed through a lens of changing climates, our results suggest that if milder winters increase the metabolic rate of overwintering ectotherms, individuals may experience greater energetic demands. Increased energy use during winter may subsequently limit individual survival and possibly even impact population persistence.

Uncertainties in energy consumption introduced by building operations and weather for a medium-size office building

Deviations between predicted and actual building energy consumption can be attributed to uncertainties introduced by four components of such projections: (1) the accuracy of the underlying models in simulation tools, (2) the accuracy of input parameters describing the design conditions of building envelopes and HVAC systems (3) actual weather, (4) variations in building operation practices. This study investigates uncertainties in energy consumption due to actual weather and building operational practices using, a simulation-based analysis of a medium-size office building. The combined effect of poor practice in building operations across multiple parameters results in an increase in energy use of 49–79% across four selected cities, while good practice reduces energy use by 15–29% across the cities. The impact of year-to-year weather fluctuation on energy use ranges from −4% to 6%. To determine the uncertainty distribution profile for annual energy use, a Monte Carlo method is applied to sample the possible combinations. This study finds that the uncertainty distribution in annual energy consumption approximately follows a log-normal distribution, and shows that the uncertainty range due to operational factors even at 80% confidence levels can dwarf the impact of design features.