Increased Energy Use Research Articles

Global warming

Global climate change has been portrayed largely as an unmitigated catastrophe for humans and the environment but, in reality, the topic is more nuanced. Although scientists agree that the climate is changing and many accept that anthropogenic increases in CO2 are to blame, there is actually both good and bad news about global warming—and some ugly news about abatement strategies. The media and the scientific literature pay little attention to the possible benefits for some parts of the world of a warming climate; bad news always attracts more attention. So let us consider these benefits, as well as the costs, before discussing the current strategies that are being used to alleviate global climate change. > …there is actually both good and bad news about global warming—and some ugly news about abatement strategies Certainly, the global climate will get warmer, but this, in itself, is not intrinsically bad; we do not necessarily live in the ‘best of all possible climates’. The Intergovernmental Panel on Climate Change (IPCC; Geneva, Switzerland) has based its estimates of how much the climate will change on the assumption that economic growth is fuelled by increased energy use, which, in turn, increases the production of greenhouse gases. Accordingly, the models that predict the greatest change in climate are driven by forecasts of rapid worldwide economic growth predominantly fuelled by fossil fuels. Yet some IPCC models, which use more realistic growth rates, predict average temperature increases by the end of this century of 2–3 oC. However, virtually all models predict that the coldest parts of the world—near the polar ice caps—will warm the most, with temperatures likely to increase most during the night and the winter (Gates et al , 1992; Houghton et al , 1992). A 2–3 oC increase is, in fact, a rather moderate climate change; …

The effect of transportation policies on energy consumption and greenhouse gas emission from urban passenger transportation

This paper offers a brief journey through twelve major cities with various policies in place to curb private vehicle use and assesses their success in term of energy consumption and greenhouse gas emission. Every region reviewed including Singapore is experiencing increase in energy use, greenhouse gas emissions and/or private vehicle ownership. In Europe, several regions improved transit quality and increased its ridership attracting non-motorized modes users instead of private vehicle users effectively increasing the total energy consumption. The author argues that policies aimed at reducing private vehicles use are failing because they do not incorporate the reality of human propensities for accessibility and comfort and they unsuccessfully try to attract customers toward services of lesser perceived quality. The demand for both accessibility and comfort will likely continue to grow with rising standards of living and will be met regardless of the environmental impact. Instead of attempting to constrain private vehicle use, the author suggests raising the competitiveness of alternate modes by investing in more attractive environments for non-motorized modes and designing transit systems actually capable of competing with private vehicles in term of perceived service quality while offering improved environmental performances.

Reducing Anthropogenic Atmospheric Carbon Loading

Higher energy use is closely linked to economic growth and social wealth. This “Viewpoint” puts forth the argument that it is not energy use as such that causes carbon-loading of the atmosphere. Higher energy use is not the problem, but rather one of the solutions to reducing anthropogenic CO2 emissions. Energy trends are examined and evidence is provided showing that the costs of producing energy from high-carbon fuels are rising while those of producing energy from low-carbon fuels are declining. The greatest challenge of increasing energy use is the protection of the integrity of the biosphere while improving quality of life. Both are possible with higher energy use.

Land Clearing and the Biofuel Carbon Debt

Increasing energy use, climate change, and carbon dioxide (CO2) emissions from fossil fuels make switching to low-carbon fuels a high priority. Biofuels are a potential low-carbon energy source, but whether biofuels offer carbon savings depends on how they are produced. Converting rainforests, peatlands, savannas, or grasslands to produce food crop-based biofuels in Brazil, Southeast Asia, and the United States creates a "biofuel carbon debt" by releasing 17 to 420 times more CO2 than the annual greenhouse gas (GHG) reductions that these biofuels would provide by displacing fossil fuels. In contrast, biofuels made from waste biomass or from biomass grown on degraded and abandoned agricultural lands planted with perennials incur little or no carbon debt and can offer immediate and sustained GHG advantages.

Comparison of thermal comfort algorithms in naturally ventilated office buildings

With the actual environmental issues of energy savings in buildings, there are more efforts to prevent any increase in energy use associated with installing air-conditioning systems. The actual standard of thermal comfort in buildings ISO 7730 is based on static model that is acceptable in air-conditioned buildings, but unreliable for the case of naturally ventilated buildings. The different field studies have shown that occupants of naturally ventilated buildings accept and prefer a significantly wider range of temperatures compared to occupants of air-conditioned buildings. The results of these field studies have contributed to develop the adaptive approach. Adaptive comfort algorithms have been integrated in EN15251 and ASHRAE standards to take into account the adaptive approach in naturally ventilated buildings. These adaptive algorithms seem to be more efficient for naturally ventilated buildings, but need to be assessed in field studies. This paper evaluates different algorithms from both static and adaptive approach in naturally ventilated buildings across a field survey that has been conducted in France in five naturally ventilated office buildings. The paper presents the methodology guidelines, and the thermal comfort algorithms considered. The results of application of different algorithms are provided with a comparative analysis to assess the applied algorithms.

Reducing Diameters of Distillation Columns with Largest Calculated Diameter at the Bottom

Methods are developed to reduce column diameter for distillation when the calculated diameter is largest at the bottom of the column. This diameter can often be reduced by generating vapor above the reboiler with an intermediate reboiler or with two-enthalpy feed. For a saturated liquid feed that is 50% n-butane and 50% n-pentane the two-enthalpy feed system reduced column volume by 8.2% with no change in energy use. For distillation of dilute acetic acid (5%)−water (95%) mixtures the best system (an intermediate reboiler) resulted in decreases in column volume as large as 53.9% with no increase in energy use. For a 50% acetic acid mixture the two-enthalpy feed system resulted in up to 32.5% reduction in column volume, while vaporizing the entire feed resulted in 31.5% volume reduction. Vapor bypass was effective in concentrated absorbers.

Balancing Diameters of Distillation Column with Vapor Feeds

Methods for balancing distillation vapor loads to achieve smaller, more-uniform diameters are developed for vapor feeds and the largest calculated diameter in the enriching section. The diameter can be reduced by (i) cooling the entire feed, (ii) cooling or condensing part of the feed while leaving the other part vapor (two-enthalpy feed), or (iii) condensing vapor inside the column with an intermediate condenser. For distillation of a saturated vapor feed of 10 mol % ethanol and 90 mol % water, the use of a two-enthalpy feed resulted in a 58% reduction in column volume with the same purity and no increase in energy use. Examples are also shown for methanol−water and n-butane−propane distillations.

The development of a dynamic model to simulate boiler controls

There has long been the need to improve the guidance for the control of multiple boiler installations. The literature shows that there is no generic guidance on how boiler plant — as opposed to the heating system — should be best controlled, despite their widespread use and many years of experience with these systems. This paper presents a simulation model that enables detailed investigation of multiple boiler operation under different control regimes. Five different conditions are presented in this paper. The first three show that individual boiler firing patterns behave as would be expected under ideal conditions. The loads for these simulations were chosen specifically to test this, and to provide some verification of the model. Two further tests were conducted to show firing patterns that may occur under typical control regimes. The resulting firing patterns showed unnecessary cycling of both boilers, a cause of premature failure and reduced efficiency. Practical applications: This paper presents the first stages of an investigation into the setting up and operation of multiple boiler control systems. A review of academic and industrial literature shows there to be very little guidance on how such control systems should be configured, and how different configurations will affect the system performance. This work is developing validated boiler models that can be used to investigate how sensor positioning and switching differentials can affect firing rates and interactions between boiler modules. In this way control settings can be more appropriately specified and commissioned. Excessive boiler cycling can lead to early failure of boilers and increased energy use. The results presented in this paper show that interaction between boilers due to poor sequence control settings will lead to additional and unnecessary cycling of boilers under part load conditions. The guidance arising from this work will help to extend boiler life and reduce fuel waste.

Management into the Development Strategies of Urbanizing Regions in Asia: Implications of Urban Function, Form, and Role

The way urbanization unfolds over the next few decades in the developing countries of Asia will have profound implications for sustainability. One of the more important opportunities is to guide urbanization along pathways that begin to uncouple these gains in well‐being from rising levels of energy use. Increasing energy use for transport, construction, climate control in houses and offices, and industrial processes is often accompanied by increasing levels of atmospheric emissions that impact human health, ecosystem functions, and the climate system. Agriculture, forestry, and animal husbandry alter carbon stocks and fluxes as carbon dioxide, methane, and black carbon. In this article we explore how carbon management could be integrated into the development strategies of cities and urbanizing regions. In particular, we explore how changes in urban form, functions, and roles might alter the timing, aggregation, spatial distribution, and composition of carbon emissions. Our emphasis is on identifying system linkages and points of leverage. The study draws primarily on emission inventories and regional development histories carried out in the regions around the cities of Manila, Jakarta, Ho Chi Minh City, New Delhi, and Chiang Mai. We find that how urban functions, such as mobility, shelter, and food, are provided has major implications for carbon emissions, and that each function is influenced by urban form and role in distinct ways. Our case studies highlight the need for major “U‐turns” in urban policy.

Milton Keynes Energy Park revisited: Changes in internal temperatures and energy usage

A follow-up study was undertaken of 15 ‘low-energy’ dwellings in Milton Keynes, UK, that were originally monitored for temperature and energy consumption from 1989 to 1991. These measurements were repeated in 2005–2006, with the results compared with the baseline using standardised daily external conditions of 5 °C. The 2005–2006 study found mean temperatures of 19.8 °C (95% confidence interval: 19.7–20.5) for living rooms and 19.3 °C (CI: 19.6–20.1) for main bedrooms. Weak evidence was found for a 10% increase in gas consumption over 15 years to 87 kWh/day (95%CI: 77–96) and overall electricity usage rose by 30% to 15 kWh/day (CI: 13.6–16.5). Dwellings were classified into three groups of low, middle, and high-energy users in 1990. In 2005–2006, this high group consumed more energy than the other two groups combined and accounted for most increases in energy use; their gas usage rose by 20% to 130 kWh/day (110–150), electricity by 75% to 28 kWh/day (CI: 25.3–31.2), and had 50% higher energy intensity at 172 Wh/m 2 (CI: 150–195). On average the high group comprised dwellings that were larger, had been extended, and whose occupants had higher incomes than the two other groups. The results suggest that research for the development of energy policy, including building regulations, should focus both on how energy is currently used and on households where the largest future increases are likely to occur.

Energy and Sustainability

![Figure][1] The theme for the 2007 annual meeting of the AAAS, to be held in San Francisco on 15 to 19 February, is “Science and Technology for Sustainable Well-Being.” The problem of energy, which is the focus of this special issue of Science linked to the meeting, looms as a central element in the web of intertwined challenges that this theme embodies. Well-being has environmental, sociopolitical, and cultural dimensions as well as economic ones, and the goal of sustainable well-being entails improving all of these dimensions in ways and to end points that are consistent with maintaining the improvements indefinitely. This challenge includes not only improving sustainably the standard of living in developing countries, but also converting to a sustainable basis the currently unsustainable practices supporting the standard of living in industrialized ones. Civilization's ability to meet this immense challenge clearly depends on our strengths in natural science and engineering. But it also depends on our strengths in the social sciences and in “social technology” in the form of business, government, and law, as well as on the societal wit and will to integrate all of these elements in pursuit of the sustainable-well-being goal. ![Figure][1] CREDIT: JUPITER IMAGES No part of this challenge is more complex or more demanding than its energy dimension. This is so in part because energy supply is tightly intertwined with national and international security and with many of the most damaging and dangerous environmental problems—from indoor air quality to global climate change—as well as with the capacity to meet basic human needs and fuel economic growth. The multiplicity and importance of these linkages would make energy a vexing issue even in a world where energy demand was constant. But that is not the world we live in. Continuing population growth and rapidly rising affluence in many parts of the globe are driving a rate of increase in energy use that has staggering implications. Even if the energy efficiency of the world economy—gross world product per unit of energy—were to continue to increase at the long-term historical rate of about 1% per year, the realization of middle-of-the-road population and economic projections would entail quadrupling world energy use in this century. In a world where today one-third of primary energy comes from oil (two-thirds of the remaining high-quality supplies of which probably lie under the volatile Middle East) and 80% comes from oil, coal, and natural gas combined (virtually all of the carbon dioxide from the combustion of which continues to go straight into the atmosphere), that middle-of-the-road energy trajectory cannot be managed simply by expanding what we are already doing. Such a path is not merely unsustainable; it is a prescription for disaster. The perils of oil dependence and climate change, coupled with the demand for large increases in the per-capita availability of energy services, compel an early transition to a different path. Its requirements include a reduction in global population growth (achievable, fortunately, by means that are desirable in their own right) and a sharply increased emphasis on improving the efficiency of energy conversion and end use (aiming to improve the energy efficiency of the world economy not by 1% per year but by 2% per year or more). Also required is a several fold increase in public and private investments to improve the technologies of energy supply. We need to know whether and how the carbon dioxide from fossil-fuel use can be affordably and reliably sequestered away from the atmosphere; whether and how nuclear energy can be made safe enough and proliferation-resistant enough to be substantially expanded worldwide; and to what extent biofuel production can be increased without intolerable impacts on food supply or ecosystem services. And we need to improve the affordability of the direct harnessing of sunlight for society's energy needs. Much insight about the current prospects in these and other dimensions of the energy problem is available in this special issue of Science. Still more about energy is on the agenda for the San Francisco meeting, along with much else germane to “Science and Technology for Sustainable Well-Being.” I commend it all to your attention. Nothing is more important to the human condition in the 21st century than rising to this set of challenges. [1]: pending:yes

The impact of increased efficiency in the industrial use of energy: A computable general equilibrium analysis for the United Kingdom

The conventional wisdom is that improving energy efficiency will lower energy use. However, there is an extensive debate in the energy economics/policy literature concerning “rebound” effects. These occur because an improvement in energy efficiency produces a fall in the effective price of energy services. The response of the economic system to this price fall at least partially offsets the expected beneficial impact of the energy efficiency gain. In this paper we use an economy–energy–environment computable general equilibrium (CGE) model for the UK to measure the impact of a 5% across the board improvement in the efficiency of energy use in all production sectors. We identify rebound effects of the order of 30–50%, but no backfire (no increase in energy use). However, these results are sensitive to the assumed structure of the labour market, key production elasticities, the time period under consideration and the mechanism through which increased government revenues are recycled back to the economy.

It's just ducky to be clean: the water repellency and water penetration resistance of swimming mallard Anas platyrhynchos ducklings

Ducklings reared by a hen swim with dry plumage a day or two after hatching, while incubator‐hatched ducklings of the same age may sink and even drown when placed in water. The common interpretation is that wild‐reared chicks receive preen oil from the parent, and this oil makes them more waterproof. Using mallard ducklings Anas platyrhynchos we tested the effect of preen and other oils, as well as hydrophilic or surfactant contaminants, on the water resistance of down. We found that the true cause for the difference between incubator and hen‐reared ducklings is the presence of hydrophilic hatching fluid residues in the down of incubator‐hatched ducklings. Once well rinsed and dried, incubator‐hatched ducklings can swim for over an hour with essentially dry down. Other tests showed that clean down is quite water resistant, and that water resistance was not improved by preen or other oils. Small amounts of preen or other oils had no effect on water repellency or wetting during surface swimming. However, oil decreased the hydraulic pressure needed to penetrate down. Down lacks the stabilizing interlocking structure of adult contour feathers, and small amounts of oil apparently cause barbules to stick together and reduce the effective number of down fibers. Detergent decreases water repellency and increases water retention, and has a more severe effect on oiled down or when applied in combination with oil. The penetration pressure of a clean down coat, 866±154 Pa, could allow static immersion to ca. 8cm before water would saturate the down and increase thermal conductance. Thus, clean ducklings have a 2×–3× safety margin for surface swimming. Saturation increases the thermal conductance of the down coat from 14.3±1.38 W/m2‐°C to 193±25 W/m2‐°C. Thus, water pollution or down contamination causing wetting can significantly increase energy use and the frequency of hypothermia.

Fuel specification, energy consumption and CO2 emission in oil refineries

Abstract The more stringent environmental quality specifications for oil products worldwide are tending to step up energy use and, consequently, CO 2 emissions at refineries. In Brazil, for example, the stipulated reduction in the sulfur content of diesel and gasoline between 2002 and 2009 should increase the energy use of Brazil's refining industry by around 30%, with effects on its CO 2 emissions. Thus, the world refining industry must deal with trade-offs between emissions of pollutants with local impacts (due to fuel specifications) and emissions of pollutants with global impacts (due to the increased energy use at refineries to remove contaminants from oil products). Two promising technology options for refineries could ease this clash in the near-to-mid term: the reduction per se of the energy use at the refinery; and the development of treatment processes using non-hydrogen consuming techniques. For instance, in Brazilian refineries, the expanded energy use resulting from severe hydrotreatment to comply with the more stringent specifications of oil products may be almost completely offset by energy saving options and alternative desulfurization techniques, if barriers to invest in technological innovations are overcome.

The cost of running uphill: linking organismal and muscle energy use in guinea fowl (Numida meleagris)

Uphill running requires more energy than level running at the same speed, largely due to the additional mechanical work of elevating the body weight. We explored the distribution of energy use among the leg muscles of guinea fowl running on the level and uphill using both organismal energy expenditure (oxygen consumption) and muscle blood flow measurements. We tested each bird under four conditions: (1) rest, (2) a moderate-speed level run at 1.5 m s(-1), (3) an incline run at 1.5 m s(-1) with a 15% gradient and (4) a fast level run at a speed eliciting the same metabolic rate as did running at a 15% gradient at 1.5 m s(-1) (2.28-2.39 m s(-1)). The organismal energy expenditure increased by 30% between the moderate-speed level run and both the fast level run and the incline run, and was matched by a proportional increase in total blood flow to the leg muscles. We found that blood flow increased significantly to nearly all the leg muscles between the moderate-speed level run and the incline run. However, the increase in flow was distributed unevenly across the leg muscles, with just three muscles being responsible for over 50% of the total increase in blood flow during uphill running. Three muscles showed significant increases in blood flow with increased incline but not with an increase in speed. Increasing the volume of active muscle may explain why in a previous study a higher maximal rate of oxygen consumption was measured during uphill running. The majority of the increase in energy expenditure between level and incline running was used in stance-phase muscles. Proximal stance-phase extensor muscles with parallel fibers and short tendons, which have been considered particularly well suited for doing positive work on the center of mass, increased their mass-specific energy use during uphill running significantly more than pinnate stance-phase muscles. This finding provides some evidence for a division of labor among muscles used for mechanical work production based on their muscle-tendon architecture. Nevertheless, 33% of the total increase in energy use (40% of the increase in stance-phase energy use) during uphill running was provided by pinnate stance-phase muscles. Swing-phase muscles also increase their energy expenditure during uphill running, although to a lesser extent than that required by running faster on the level. These results suggest that neither muscle-tendon nor musculoskeletal architecture appear to greatly restrict the ability of muscles to do work during locomotor tasks such as uphill running, and that the added energy cost of running uphill is not solely due to lifting the body center of mass.

The energetic costs of trunk and distal-limb loading during walking and running in guinea fowlNumida meleagris

We examined the changes in muscle energy use in guinea fowl running at 1.5 m s-1 either unloaded, or carrying trunk loads equal to 23% of body mass, or loads on their distal legs equal to a total of 5% of body mass. We estimated muscle energy use by measuring blood flow to all of the leg muscles using injected microspheres. Total blood flow to the leg muscles increased by approximately 15% under both loading conditions, which matched the percentage increase in net organismal metabolic rate. Significant increases in energy use (inferred from blood flow) above that found in unloaded birds were found in 12 muscles in trunk-loaded birds, with most of the increases restricted to stance-phase muscles, as predicted. Just three of these muscles, the femerotibialis, the iliotibialis lateralis pars postacetabularis and the fibularis longus accounted for 70% of the increased energy use. Noticeably absent from the group of muscles that increased energy use during trunk loading were several large biarticular muscles that have extensor actions at the hip or ankle, but flexor actions at the knee. We concluded that the low energetic cost of carrying trunk loads in guinea fowl may rely on the activation of a group of muscles that together provide support and propulsion across all the major joints, without producing opposing moments at other joints that could potentially waste energy. The specific leg muscles responsible for the increase in metabolism during trunk loading also suggest that the energy cost of producing mechanical work may be an important determinant of the cost of carrying extra mass on the trunk. During distal-limb loading, eleven leg muscles had significant increases in energy use, but unlike during trunk loading, both stance- and swing-phase muscles had large increases in energy use. This distribution of energy use between stance and swing agrees with the prediction that increased mechanical work determines the cost of limb loading, because a substantial fraction of the increased segmental work during distal-limb loading in guinea fowl has been found to occur during stance.

The energetic costs of trunk and distal-limb loading during walking and running in guinea fowlNumida meleagris

We examined the energetic cost of loading the trunk or distal portion of the leg in walking and running guinea fowl (Numida meleagris). These different loading regimes were designed to separately influence the energy use by muscles used during the stance and swing phases of the stride. Metabolic rate, estimated from oxygen consumption, was measured while birds locomoted on a motorized treadmill at speeds from 0.5 to 2.0 m s-1, either unloaded, or with a mass equivalent to 23% of their body mass carried on their backs, or with masses equal to approximately 2.5% of their body mass attached to each tarsometatarsal segment. In separate experiments, we also measured the duration of stance and swing in unloaded, trunk-loaded, or limb-loaded birds. In the unloaded and limb-loaded birds, we also calculated the mechanical energy of the tarsometatarsal segment throughout the stride. Trunk and limb loads caused similar increases in metabolic rate. During trunk loading, the net metabolic rate (gross metabolic rate-resting metabolic rate) increased by 17% above the unloaded value across all speeds. This percentage increase is less than has been found in most studies of humans and other mammals. The economical load carriage of guinea fowl is consistent with predictions based on the relative cost of the stance and swing phases of the stride in this species. However, the available comparative data and considerations of the factors that determine the cost of carrying extra mass lead us to the conclusion that the cost of load carrying is unlikely to be a reliable indicator of the distribution of energy use in stance and swing. Both loading regimes caused small changes in the swing and/or stance durations, but these changes were less than 10%. Loading the tarsometatarsal segment increased its segmental energy by 4.1 times and the segmental mechanical power averaged over the stride by 3.8 times. The increases in metabolism associated with limb loading appear to be linked to the increases in mechanical power. The delta efficiency (change in mechanical power divided by the change in metabolic power) of producing this power increased from 11% in walking to approximately 25% in running. Although tarsometatarsal loading was designed to increase the mechanical energy during swing phase, 40% of the increase in segmental energy occurred during late stance. Thus, the increased energy demand of distal limb loading in guinea fowl is predicted to cause increases in energy use by both stance- and swing-phase muscles.

World energy analysis: H 2 now or later?

This is a study of world energy resource sustainability within the context of resource peak production dates, advanced energy use technologies in the transportation and electricity generation energy use sectors, and alternative fuel production including hydrogen. The finding causing the most concern is the projection of a peak in global conventional oil production between now and 2023. In addition, the findings indicate that the peak production date for natural gas, coal, and uranium could occur by 2050. The central question is whether oil production from non-conventional oil resources can be increased at a fast enough rate to offset declines in conventional oil production. The development of non-conventional oil production raises concerns about increased energy use, greenhouse gas emissions, and water issues. Due to the emerging fossil fuel resource constraints in coming decades, this study concludes that it is prudent to begin the development of hydrogen production and distribution systems in the near-term. The hydrogen gas is to be initially used by fuel cell vehicles, which will eliminate tailpipe greenhouse gas emissions. With a lowering of H 2 production costs through the amortization of system components, H 2 can be an economic fuel source for electricity generation post-2040.

Does trade liberalization increase national energy use?

This paper utilises the theoretical principles of Antweiler et al. [Antweiler, W. B.R. Copeland and M.S. Taylor (2001) Is Free Trade Good for the Environment? American Economic Review, 91, 4, pp. 877–908.] to estimate empirically the linkages between trade liberalization and energy use. Focusing on scale, technique and composition effects, results suggest that trade will increase energy use for the mean country in the sample.

Indirect Effects to Include in Strategic Environmental Assessments of Transport Infrastructure Investments

Indirect effects are important considerations when making consequence analyses in general and in strategic environmental assessments in particular of potential transport solutions and infrastructure plans. The primary objective of this paper is to emphasize the need for a deeper understanding of the long‐term system effects of investments in transport infrastructure with a focus on the structuring effects that roads and railways have on society, e.g. altered transport patterns, altered settlement structures and changes in use of the built environment. Special attention is given to the following potential indirect effects: increased total transport volume, increased share of private motorists and truck transport, increased urban sprawl, and increased energy use in buildings. The conditions that determine the power of the effects are discussed and a number of key factors to be considered in transport infrastructure planning, especially in strategic environmental assessments, are suggested. Since many indirect effects emerge over time, an extended time perspective is of essence. Therefore, scenario techniques may be useful when analysing indirect effects in transport planning processes.