Changes In Energy Use Research Articles

Governing sustainable industrial energy use: Energy transitions in Nigeria's manufacturing sector

The governance of industrial energy use in recent times has been driven by the quest for greater energy security and sustainable industrial growth. Sustainable use of energy necessitates a rethink in the production, use and governance of energy resources that stimulates and supports transition to a more effective and efficient energy system. However, how do we ensure an effective transition in industrial energy use in the midst of gross energy poverty within a developing country context? This paper explores the motives and drivers of changes in energy use within the industrial sector. Statistical data from published reports, as well as informal interviews of stakeholders in Nigeria's industrial sector were used. Following analysis of data, four important salient phases (eras) of industrial energy transition in Nigeria's manufacturing sector was established. These distinct eras are: (1) Grid-dependent era; (2) Self-generation era; (3) Industrial energy outsourcing era; (4) Industrial energy conservation era. The study reveals that: outsourcing of industrial services; cost reduction; and business realignment motives are key drivers of transitions in Nigeria's industrial sector. This paper concludes by highlighting the implications of these changes for the future of energy and sustainable industrial growth in Nigeria.

Modelling energy demand from higher education institutions: A case study of the UK

Among the various sustainability goals of higher education institutions (HEIs), reducing energy use and carbon emissions are particularly important. However, not much is known about energy demand from the higher education sector – especially since there is a lack of robust models of energy demand in this sector. This paper, the first to utilize a panel dataset and advanced panel econometric techniques in order to model energy use in higher education, investigates variations in energy use between HEIs (cross-sectional analysis), and also changes in energy use over time (temporal analysis), using the UK as a case study. We argue that panel dataset and methods are more useful for understanding growth (and reduction) in energy use within the HE sector than the methods used within previous cross-sectional studies. Results show that, over time and also across the sector, energy consumption in the HEIs increases with increases in income and floor space, but at a slower rate. As HEIs grow overall (in terms of income, floor space, student and staff number) over time, they become more 'energy efficient' (using less energy per unit of area, population or income), indicating economies of scale in the temporal dimension. Results also show that after controlling for income and size, research intensive HEIs consume more energy. We also find a small but statistically significant effect of energy prices on energy consumption, as might be expected. Simulation using the model parameters for an example scenario suggests that energy consumption will continue to increase unless there is a significant change in the policies driving income growth and spatial expansion in the HE sector in the UK.

Assessing the trends of energy use of public non-domestic buildings in England and Wales

Accessing sufficient data for understanding how energy is used in non-domestic buildings is deemed to be a challenge in many countries. In the UK, such a challenge has led to limited understanding of long-term changes in energy use of buildings. This study aims to develop a deeper understanding of the trends in energy use across the public sector non-domestic buildings in England. Display energy certificate (DEC) data which relate to 59,740 public sector non-domestic buildings in England and Wales were analysed. Statistical analyses were carried out to understand both the latest patterns of energy use and how they have changed between 2010 and 2016. The patterns of energy use of various public-sector buildings were found to have gradually changed over the seven-year period. An imminent release of a revised dataset was deemed necessary for understanding the performance of buildings to support the aspirations set out in the clean growth strategy. The study pointed to a need for regularly gathering and sharing data for understanding the changes in the patterns of energy use of the stock. Developing a framework that can facilitate this would enable various stakeholders make informed decisions for improving energy efficiency of the UK’s non-domestic buildings. Practical application: Statistics on electrical and fossil-thermal energy use intensity provide up-to-date reference points for assessing operational energy efficiency of public sector buildings. Principles for developing a framework are provided to support various stakeholders make informed decisions on for example setting design targets or making capital investments.

Fuel-factor nesting structures in CGE models of China

Fuel-factor nesting structures are critical features of CGE models but have rarely been chosen in a robust manner. This study thoroughly examines two popular fuel-factor nesting structures in CGE models of China, namely KL-E11In which, Capital (K) and labour (L) forms of KL bundle, which in turn forms a KL-E bundle with energy (E). and KE-L.22In which, capital (K) and energy (E) forms of KE bundle, which in turn forms a KE-L bundle with labour (L). We use non-linear algorithms to estimate the underlying CES production functions of these two structures. We recommend the latter to be used in CGE models of China, as it exhibits 1) better goodness of fit, 2) better convergence, and 3) better compliance with economic meanings. Our estimations show that the ranges for the inner- and outer-CES parameters33The inner-elasticity in a KE-L nesting structure refers to CES parameter between capital and energy, and the outer-elasticity in a KE-L nesting structure refers to the CES parameter between the capital-energy bundle and labour. in our preferred KE-L structure are 0.6–0.8 and 0.7–0.9, respectively. Applying these in a CGE model, we find nesting strategies used in previous CGE exercises might have overestimated energy conservation costs in China. A decomposition shows that, using our KE-L, changes in energy use are dominate by output effects rather than substitution effects.

In situ swimming behaviors and oxygen consumption rates of juvenile lemon sharks (Negaprion brevirostris)

Knowing how often animals engage in different behaviors and their energetic costs may explain why animals behave the way they do in the wild. This study sought to investigate the relationship between the frequency of various swimming behaviors and their associated energetic costs (oxygen consumption rates) in situ for juvenile lemon sharks (Negaprion brevirostris). Behaviors were identified for captive animals and remotely observed for animals in the wild with accelerometers, and oxygen consumption rates of behaviors were estimated using acceleration-calibrated relationships. Lemon sharks rested infrequently (4.3% of deployment), and the occurrence of active swimming behaviors was inversely related to their respective oxygen consumption rates. Furthermore, time of day and tide state influenced when lemon sharks exhibited active swimming behaviors – but not resting – such that sharks were most active during the day on flooding tides. Oxygen consumption rates also differed across and within different behaviors with time of day and tide state, although mean oxygen consumption rates were highest on daytime flooding tides and uniformly reduced across all other diel and tide combinations. Despite variation in oxygen consumption rates, however, lemon shark activity occurred at 32.3–35.6% of their aerobic metabolic scope. These data do not provide a clear oxygen consumption basis for swimming behaviors observed in situ, which may have been masked by potentially stronger ecological drivers (e.g., predator-prey dynamics). However, these data are relevant to linking behavioral modifications to changes in energy use that shows much promise for addressing conservation issues in fishes.

Adaptive control of dynamic balance in human gait on a split-belt treadmill.

Human bipedal gait is inherently unstable, and staying upright requires adaptive control of dynamic balance. Little is known about adaptive control of dynamic balance in reaction to long-term, continuous perturbations. We examined how dynamic balance control adapts to a continuous perturbation in gait, by letting people walk faster with one leg than the other on a treadmill with two belts (i.e. split-belt walking). In addition, we assessed whether changes in mediolateral dynamic balance control coincide with changes in energy use during split-belt adaptation. In 9min of split-belt gait, mediolateral margins of stability and mediolateral foot roll-off changed during adaptation to the imposed gait asymmetry, especially on the fast side, and returned to baseline during washout. Interestingly, no changes in mediolateral foot placement (i.e. step width) were found during split-belt adaptation. Furthermore, the initial margin of stability and subsequent mediolateral foot roll-off were strongly coupled to maintain mediolateral dynamic balance throughout the gait cycle. Consistent with previous results, net metabolic power was reduced during split-belt adaptation, but changes in mediolateral dynamic balance control were not correlated with the reduction of net metabolic power during split-belt adaptation. Overall, this study has shown that a complementary mechanism of relative foot positioning and mediolateral foot roll-off adapts to continuously imposed gait asymmetry to maintain dynamic balance in human bipedal gait.

Design principles for energy flexible production systems

The change of the energy supply from conventional energy sources to renewable ones is a challenge for the whole society. It is a well-known fact that this alteration causes increasing energy volatility and therefore requires a change in energy use. When it comes to production matters, energy is yet a resource which is available immediately on-demand. In the future, energy needs to be considered as a resource during the pro-duction planning process. Therefore, certain design principles for energy flexible production systems must be developed and will be presented in this paper. Finally, the paper also shows in which way the design principles affect the specific energy flexibility characteristics.

Global Energy Consumption in a Warming Climate

We combine econometric analysis of the response of energy demand to temperature and humidity exposure with future scenarios of climate change and socioeconomic development to quantify the impacts of future climate warming on final energy consumption across the world. Globally, changes in climate circa 2050 have a moderate impact on energy consumption of 7–17%, depending on the degree of warming. Impacts vary in sign and magnitude across regions, fuels, and sectors. Climatically-induced changes in energy use are larger in tropical regions. Almost all continents experience increases in energy demand, driven by the commercial and industrial sectors. In Europe declines in energy use by residences drive an overall reduction in aggregate final energy. Energy use increases in almost all G20 economies located in the tropics, while outside of Europe G20 countries in temperate regions experience both increasing and declining total energy use, depending on the incidence of changes in the frequency of hot and cold days. The effect of climate change is regressive, with the incidence of increased energy demand overwhelmingly falling on low- and middle-income countries, raising the question whether climate change could exacerbate energy poverty.

Assessing energy use and overheating risk in net zero energy dwellings in UK

This paper presents the methodological approach and findings of a simulation study of advanced energy conservation, generation and management technologies applied to two case study dwellings in the UK, so as to achieve net zero energy (NZE) target that includes a reduction of net regulated energy (HVAC) to 0kWh/m2 per year and energy generation of at least 50kWh/m2 per year. The performance of the dwellings are also tested for a change in energy use and risk of summertime overheating in future climates in the short (2030s), medium (2050s) and long term (2080s).The findings indicate that to meet the NZE targets, regulated loads need to reduce by about half (over current Building Regulations) with community (rather than building-level) renewables playing a major role. It is also found that the NZE targets, given current regulations, are not particularly difficult to achieve in design with regard to energy efficiency but are highly expectant with regard to renewable energy. Further, summertime overheating is projected to be a risk for net zero energy dwellings by the 2050s. Despite this the regulated energy use of both dwellings is projected to reduce by 11kWh/m2/yr, accompanied by a small increase in renewable generation (2kWh/m2/yr).

Analysing Energy Induced Technological Changes in Indian Economy: A Sectoral Study

Recognising the nexus between growth and energy use, a fast growing country like India, is an ideal case for empirical assessment of increasing energy use in terms of consumption pattern driven by shifts in demand and technological changes. While the introduction of new technology contributes to lower energy use due to improved efficiency, the introduction of energy consuming machinery itself may cause an increase in energy use. Therefore, it is important to explore the sectoral dynamics of development. We study the relative contributions at the sector level in an economy-wide framework using the hybrid Input-output model for structural decomposition analysis. Results for the overall economy show that changes in the production technology have been energy saving with a gradual response of non-energy inputs, as compared with energy inputs. Comparison of the changes in energy use highlights the need to reduce energy requirements from final demand expansion either through price corrections or along with a parallel improvement in technological performance.

Decomposition Analysis of Energy Consumption in Pakistan for the Period 1990-2013

The final energy consumption in Pakistan has doubled during the last two decades. Investigating the factors responsible for changes in energy use is important for future projections. Decomposition techniques enable us to quantify the contributing factors in aggregate energy change. This study attempts to investigate the factors behind the aggregate change in energy consumption over the period 1990-2013 using Logarithmic Mean Divisia Index (LMDI) decomposition technique. LMDI decomposes the overall change in energy use into three effects namely, activity, structural, and intensity effects. Results of the study suggest that observed increase in Pakistan’s energy consumption is primarily due to the activity and structural effects. The energy intensity of overall economy has decreased showing an increase in energy efficiency, though at a decreasing rate over time. The quantification of energy imports based on projections shows that Pakistan may face serious fiscal challenge by 2025 due to extremely large energy import bill and possible energy price shocks. There is a need to put efforts towards reducing the gap between energy supply and demand, diversifying domestic energy production including increased reliance on renewables, efforts towards energy and environment conservation, and efficient use of available resources.

Measuring Plant Level Energy Efficiency and Technical Change in the U.S. Metal-Based Durable Manufacturing Sector Using Stochastic Frontier Analysis

This study analyzes the electric and thermal energy efficiency for five different metal-based durable manufacturing industries in the United States from 1987-2012 at the 3 digit North American Industry Classification System (NAICS) level. Using confidential plant-level data on energy use and production from the quinquennial U.S. Economic Census, a stochastic frontier regression analysis (SFA) is applied in six repeated cross sections for each five year census. The SFA controls for energy prices and climate-driven energy demand (heating degree days - HDD - and cooling degree days - CDD) due to differences in plant level locations, as well as 6-digit NAICS industry effects. A Malmquist index is used to decompose aggregate plant technical change in energy use into indices of efficiency and frontier (best practice) change. Own energy price elasticities range from -.7 to -1.0, with electricity tending to have slightly higher elasticity than fuel. Mean efficiency estimates (100 percent equals best practice level) range from a low of 32 percent (thermal 334 - Computer and Electronic Products) to a high of 86 percent (electricity 332 - Fabricated Metal Products). Electric efficiency is consistently better than thermal efficiency for all NAICS. There is no clear pattern to the decomposition of aggregate technical Thermal change. In some years efficiency improvement dominates; in other years aggregate technical change is driven by improvement in best practice.

Life-cycle energy use and GHG emissions of waste television treatment system in China

Waste electrical and electronic equipment (WEEE) has become one of the fastest growing solid waste. The development of WEEE treatment facility will promote the infrastructure to realize sustainable waste management. At present, the treatment of cathode ray tube televisions (TVs) forms the dominant part of the WEEE treatment system in China. In this paper, a life cycle assessment is conducted to estimate the energy use and greenhouse gas (GHG) emissions arising from CRT TV treatment. Three treatment scenarios for CRT TV are analysed: (i) the current situation in China (Current China Scenario), (ii) one with encouragement from China’s WEEE Directive (WEEE Directive Scenario), and (iii) the development of more advanced techniques (Advanced Technique Scenario). The results show that the changes in energy use caused by the three scenarios are −526.51, −475, and −556.07MJ, respectively. Meanwhile, the relevant GHG emissions are −19.59, −20.43, and −25.82kg CO2-eq, respectively. The scenario involving encouragement from China’s WEEE Directive offers no benefit compared to the current situation in terms of energy use and GHG emissions. Moreover, the Advanced Technique Scenario is more efficient than the Current China Scenario. In consideration of the main contribution, the results reveal that CRT glass recycling contributes the highest energy use and GHG emissions to CRT TV treatment, besides, displaced plastic and displaced glass account for the main proportions with regard to any accrued environmental gain. A sensitivity analysis is also carried out to quantify the influence of collection efficiency and the lead (Pb) recovery rate on environmental performance. In so doing, some recommendations are proposed to realize the sustainable development of the WEEE treatment system in China.

Case studies of cavity and external wall insulation retrofitted under the Irish Home Energy Saving Scheme: Technical analysis and occupant perspectives

The residential sector represents 27% of primary energy consumption in Ireland. This paper examines the case study of the Irish government’s national grant scheme to encourage energy efficiency retrofit in private housing. That is the Home Energy Saving (HES) Scheme, later rebranded the Better Energy: Homes (BEH) Scheme. The methodology involved monitoring several homes immediately before and after retrofit alongside discussions with occupants. The examination focused on specific measures commonly introduced through the HES/BEH programme − cavity and external wall insulation. It has been found that a significant decrease in heat loss through the walls was measured in all cases. Regardless, the occupant played a considerable role in the change in energy use in the buildings, and the main motivation for retrofit was found to be comfort and not energy savings or environmental concerns. As a result, the actual energy savings are notably less than the potential savings had the pre and post comfort levels remained the same.

Aura OMI observations of regional SO<sub>2</sub> and NO<sub>2</sub> pollution changes from 2005 to 2015

Abstract. The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2) and sulfur dioxide (SO2), since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper, we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2015, by more than 40 and 80 %, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal-fired power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50 % reduction in 2012–2015, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 %, respectively, from 2005 to 2015. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved valuable in documenting rapid changes in air quality over different parts of the world during last decade. The baseline established during the first 11 years of OMI is indispensable for the interpretation of air quality measurements from current and future satellite atmospheric composition missions.

Vehicle Efficiency and Tractive Work: Rate of Change for the Past Decade and Accelerated Progress Required for U.S. Fuel Economy and CO2 Regulations

A major driving force for change in light-duty vehicle design and technology is the National Highway Traffic Safety Administration (NHTSA) and the U.S. Environmental Protection Agency (EPA) joint final rules concerning Corporate Average Fuel Economy (CAFE) and greenhouse gas (GHG) emissions for model years (MY) 2016 through 2025 passenger cars and light trucks. The chief goal of this current study is to compare the already rapid pace of fuel economy improvement and technological change over the previous decade to the needed rate of change to meet regulations over the next decade. EPA and NHTSA comparisons of the MY 2004 US light-duty vehicle fleet to the MY 2014 fleet shows improved fuel economy (FE) of approximately 28% using the same FE estimating method mandated for CAFE regulations. Future predictions by EPA and NHTSA concerning ensemble fleet fuel economy are examined as an indicator of needed vehicle rate-of-change. A set of 40 same-model vehicle pairs for MY 2005 and MY 2015 is compared to examine changes in energy use and related technological change over the 10 year period. Powertrain improvements measured as increased vehicle efficiency, and vehicle mass-glider improvements measured as decreased tractive work requirements are quantified. The focus is first onmore » conventional gasoline powertrain vehicles which currently dominate the market, with hybrids also examined due to their high potential importance for CAFE compliance. Most hybrid vehicles with significant sales in 2014 were represented in the study. Results show 10 years of progress for the studied vehicle set includes lowered tractive effort of about 5.6% and improved powertrain efficiency of about 16.5%. Further analysis shows that this high rate of past progress must increase by about 50% in order to meet the 2025 CAFE standards. Examination of where certain MY 2015 vehicle compare to CAFE regulations is offered as well as some simple conjecture on what is needed to meet regulations under reasonable assumptions.« less

Sources of structural change in energy use: A decomposition analysis for Korea

ABSTRACTQuantifying the sources of change in energy use by decomposition can provide policymakers with useful information, especially for Korea, which has energy-intensive industries such as steel and petrochemicals. In this article, intermediate energy demand is analyzed using a four-part structural decomposition model. The proposed model can distinguish a structure effect from the Leontief effect. From the results, a noticeable structure effect is observed from 1995 to 2005. Moreover, the results show that the Leontief effect can be estimated oppositely according to energy demand sector. Consequently, this article shows the necessity of investigating intermediate demand when analyzing energy use applying a decomposition analysis method.

What drives consumption of wood energy in the residential sector of small cities in Europe and how that can affect forest resources locally? The case of Bragança, Portugal

SUMMARY A study in a small city in Portugal was conducted to improve the understanding of the role of wood energy in the residential energy services in small cities in Europe, the factors affecting the use of wood consumption in households, and how changes in consumption drivers affect forest resources. The hypothesis that small cities in Europe have wood energy consumption much larger than expected was analysed based on survey data collection. Drivers were analysed through statistical modelling. Wood, used in 42% of households, represented 43% of the city's final energy consumption. The probability of wood energy use depended of resident's age, construction type, area and year. The amount of wood used was explained by resident's education, construction type and age, and energy function. Changes in drivers suggest a decrease in wood demand in the near future although new energy products and changes in energy use can balance this trend.

Past Management of Energy Demand: Promotion and Adoption of Electric Heating in Britain 1945-1964

Abstract Changes in energy use have been a key part of many dramatic social, economic and environmental changes during the twentieth century and before, making energy interesting to environmental historians. Today, policy makers seek reductions in energy use and carbon emissions to mitigate climate change through demand management policies that attempt to reduce usage or shift it in time away from peak demand. To understand the impact of such policies it is necessary to understand both how they were promoted and received. This article discusses electric heating in early post-war Britain, which was seen as a particularly problematic energy use, as electric fires were used at peak times. The Electricity Development Association (EDA) tried simultaneously to reduce undesirable peak demand while encouraging increased demand more generally. In the late 1940s it advertised against peak use of electric fires, whereas in the 1950s and 1960s it instead concentrated on promoting off-peak heating appliances, first under-floor heating and then block storage heaters. I will analyse how the London County Council and its tenants adopted and adapted electric underfloor heating, illustrating the complicated way demand is made and unmade. The paper concludes that, while demand management has been attempted by the electricity industry since well before the 1970s, these attempts only had a limited effect on the overall trend towards increasing demand, in part to do with how these promotions were adopted.

Energy use, blue water footprint, and greenhouse gas emissions for current food consumption patterns and dietary recommendations in the US

This article measures the changes in energy use, blue water footprint, and greenhouse gas (GHG) emissions associated with shifting from current US food consumption patterns to three dietary scenarios, which are based, in part, on the 2010 USDA Dietary Guidelines (US Department of Agriculture and US Department of Health and Human Services in Dietary Guidelines for Americans, 2010, 7th edn, US Government Printing Office, Washington, 2010). Amidst the current overweight and obesity epidemic in the USA, the Dietary Guidelines provide food and beverage recommendations that are intended to help individuals achieve and maintain healthy weight. The three dietary scenarios we examine include (1) reducing Caloric intake levels to achieve “normal” weight without shifting food mix, (2) switching current food mix to USDA recommended food patterns, without reducing Caloric intake, and (3) reducing Caloric intake levels and shifting current food mix to USDA recommended food patterns, which support healthy weight. This study finds that shifting from the current US diet to dietary Scenario 1 decreases energy use, blue water footprint, and GHG emissions by around 9 %, while shifting to dietary Scenario 2 increases energy use by 43 %, blue water footprint by 16 %, and GHG emissions by 11 %. Shifting to dietary Scenario 3, which accounts for both reduced Caloric intake and a shift to the USDA recommended food mix, increases energy use by 38 %, blue water footprint by 10 %, and GHG emissions by 6 %. These perhaps counterintuitive results are primarily due to USDA recommendations for greater Caloric intake of fruits, vegetables, dairy, and fish/seafood, which have relatively high resource use and emissions per Calorie.