Energy Efficiency Opportunities Research Articles

Assessment opportunities for energy efficiency in Ecuadorian road transport

El transporte es vital para el desarrollo social y económico de las sociedades alrededor del mundo. Por lo tanto, se tiene que considerar que el transporte masivo ha incrementado a través del tiempo con el consumo discriminado de combustibles fósiles que han servido para suplir la demanda en el transporte. Existen impactos sociales y medio ambientales que tienen que ser evaluados junto con la demanda de energía en Ecuador. La misma que en 2012 equivalió a 46 millones de BEP, donde 73% fue consumida por vehículos de carga pesada y 32% por vehículos de carga liviana. Este patrón de consumo combinado con una flota de vehículos ineficiente y un subsidio discriminado resulto en un derroche excesivo de energía. La investigación se enfoca en el análisis de la situación del transporte en Ecuador, para identificar el desperdicio de energía, el medio ambiente, y las oportunidades de eficiencia energética en este sector.

Household analysis identifies water-related energy efficiency opportunities

Water heating accounts for around one third of household direct energy use. This energy demand is some four times greater than lighting. Here we use detailed monitoring and modelling of seven individual households to quantify major factors. Using normalized sensitivity results we demonstrate (i) high variability and (ii) a large and consistent influence of shower duration, flow rate, frequency and temperature along with hot water system efficiency, adult population, and the temperature of cold water. A 10% change in these factors influenced 0.1–0.9kWh/hh-person.d, equivalent to a 2–3% of total household energy use. We draw on 5399 shower events from a further 94 households, and 491 shower temperature measurements to understand the scope for changes to the households. Individual parameters variation guided by these larger datasets demonstrated shower duration and flow rate offer most scope for change. The work helps guide city-scale analysis of household water-related energy demand. It also supports the tailoring of behavioural and technological water-efficiency programs towards those with strongest potential to influence energy. Strong interaction between parameters suggests that programs aiming to influence water-related energy need to be aware of how this interplay either amplifies, or diminishes, the intended energy savings.

Quantifying Energy and Water Savings in the U.S. Residential Sector

Stress on water and energy utilities, including natural resource depletion, infrastructure deterioration, and growing populations, threatens the ability to provide reliable and sustainable service. This study presents a demand-side management decision-making tool to evaluate energy and water efficiency opportunities at the residential level, including both direct and indirect consumption. The energy-water nexus accounts for indirect resource consumption, including water-for-energy and energy-for-water. We examine the relationship between water and energy in common household appliances and fixtures, comparing baseline appliances to ENERGY STAR or WaterSense appliances, using a cost abatement analysis for the average U.S. household, yielding a potential annual per household savings of 7600 kWh and 39 600 gallons, with most upgrades having negative abatement cost. We refine the national average cost abatement curves to understand regional relationships, specifically for the urban environments of Los Angeles, Chicago, and New York. Cost abatement curves display per unit cost savings related to overall direct and indirect energy and water efficiency, allowing utilities, policy makers, and homeowners to consider the relationship between energy and water when making decisions. Our research fills an important gap of the energy-water nexus in a residential unit and provides a decision making tool for policy initiatives.

Measuring energy conservation on Nova Scotia (NS) farms: A 2004 to 2011 comparison

Many jurisdictions, including Nova Scotia (NS), have implemented policies and programs around energy. The NS government has targeted energy efficiency and more renewable energy as two main policy areas. The NS Department of Agriculture has taken initiative to provide support to implement energy conservation, energy efficiency and renewable energy opportunities in recent years but have these programs and policies been effective? A baseline energy use survey was conducted in 2005 and responses from mail surveys in 2012 (n=273, 11.4% response rate) were used to measure the change in NS farm energy use data reported for 2004 and 2011. There have been significant reductions in energy use on NS farms. On average, NS farmers spent $8790 on energy expenses in 2011 compared to $11,228 in 2004. Adjusting for inflation, this is a 32% decrease, despite energy commodity pricing increases beyond the inflation rate. This is likely due to a decrease in energy use and a shift from gasoline use to diesel use. By the end of 2012, 36.0% of NS farmers (more than 860) had received some level of support to evaluate their energy options. This includes 410 energy audits compared to only 36 by the end of 2005.

Opportunity for compute partitioning in pursuit of energy-efficient systems

Performance of computing systems, from handhelds to supercomputers, is increasingly constrained by the energy consumed. A significant and increasing fraction of the energy is consumed in the movement of data. In a compute node, caches have been very effective in reducing data movement by exploiting the available data locality in programs. Program regions with poor data locality, then effect most of the data movement, and consequently consume an ever larger fraction of energy. In this paper we explore the energy efficiency opportunity of minimizing the data movement in precisely such program regions, by first imagining the possibility of compute near memory, and then partitioning the program’s execution between a compute core and the compute near memory (CnM). Due to the emergence of 3D stacked memory, a CnM implementation appears more realistic. Our focus is on evaluating the partitioning opportunity in applications and to do a limit study of systems enabled with CnM capabilities to understand and guide their architectural embodiment. We describe an automated method of analyzing the data access pattern of optimized workload binaries, via a binary-instrumentation tool called SnapCnM, to identify the beneficial program regions (loops) for CnM execution.We also perform a limit study to evaluate the impact of such partitioning over a range of parameters affecting CnM design choices. Our results show that compute partitioning a small (<10%) fraction of a workload can improve its energy efficiency from 3% (for compute-bound applications) to 27% (for memory-bound applications). From the study in this work we discuss the important aspects that help to shape the future CnM design space.

Energy efficiency opportunities in the service plants of cast iron foundries in Italy

Though in a foundry most of the energy is used in the process plants and particularly in energizing furnaces, service plants require absolutely large amounts of energy, above all as electricity. The most energy-consuming service is compressed air preparation, but large amounts are due to lighting, heating, ventilation and air conditioning, pumps and fans. These energy users are common to most of the industrial branches with different weights both in absolute and relative terms. This article reports on the experience of some energy audits carried out in five Italian cast iron foundries allowing to identify the relative importance of different services in this industrial branch. The analysis is based on real data measured during the audits. Energy saving actions were then conceived, comparing the results of new technologies applied in some factory sectors and the energy usage of the previous equipment.

Assessing the thermodynamic performance of Irish municipal wastewater treatment plants using exergy analysis: a potential benchmarking approach

Wastewater treatment is a resource intensive process utilising several inputs such as energy, chemicals and water to produce an effluent that meets designated environmental standards. It is predicted that increasingly stringent discharge requirements will include better treatment of nutrients and the need to treat emerging pollutants, i.e. pollutants not commonly monitored in the environment currently, but which have the potential to cause environmental damage. One expected outcome of increased effluent standards is higher energy consumption. Coupled with this, fluctuating energy costs and the need to mitigate fossil fuel based carbon emissions have led to a greater focus on the energy efficient operation of wastewater treatment plants. Exergy Analysis has been identified as a useful tool to assess the resource efficiency of thermal and other energy systems. The exergy approach provides a rational basis for process optimisation, where, in theory, the processes with the greatest exergy destruction represent the greatest energy efficiency opportunities. In this research, exergy analysis has been used to assess and compare the energy/resource efficiency of two Irish wastewater treatment plants. One important objective is to investigate the appropriateness of exergy analysis as a potential benchmarking approach for wastewater treatment plants. Although the two wastewater treatment plants are of similar scale, and use similar technologies, the results of the exergy analysis were significantly different. For example, the secondary treatment exergy destruction differed by as much as 67% between the two wastewater treatment plants. Furthermore, the coupled pre-treatment and secondary treatment exergetic efficiencies of both plants differed significantly: one wastewater treatment plant had an exergetic efficiency of 27.5% in comparison with 40.2% for the second plant. One important mitigating factor was identified: the difference between their incoming wastewater concentrations. These results indicate that metrics such as exergy destruction when combined with consideration of water quality can be a useful tool in the comparing the overall performance of wastewater treatment plants.

Energy Efficiency and Contact Opportunities Tradeoff in Opportunistic Mobile Networks

To discover neighbor nodes, nodes in opportunistic mobile networks (OppNets) have to probe their environment continuously. This can be an extremely energy-consuming process. If nodes probe very frequently, a lot of energy will be consumed in the contact probing process and might be inefficient. On the other hand, infrequent contact probing might cause nodes to miss many of their contacts. Therefore, there exists a tradeoff between energy efficiency and contact opportunities in OppNets. To investigate this tradeoff, we first propose a model to investigate the contact probing process based on the random-waypoint model and obtain the expressions of the single detecting probability and the double detecting probability. Moreover, we also demonstrate that among all contact probing strategies with the same average probing interval, which do not have preknowledge of the contact process, the strategy that probes at a constant interval performs better than any arbitrary probing strategy in expectation in the single contact probing process. Then, extensive simulations are conducted to validate the correctness of our proposed model. Finally, based on the proposed model, we analyze the tradeoff between energy efficiency and the total number of effective contacts in the single and double contact probing processes. Our results show that the total number of effective contacts in the single and double contact probing processes has a lower bound and an upper bound, and the good tradeoff points are obviously different when the speed of nodes is different.

Action-Oriented Energy Benchmarking for Nonresidential Buildings

The complex process of improving the energy efficiency of a building begins with understanding baseline conditions and assessing the potential for specific improvements. Traditional benchmarking typically addresses the status quo , e.g., by comparing the building to its peers at one point in time or longitudinally. Action-oriented benchmarking extends this process by also inferring potential energy-efficiency opportunities. Doing so, however, requires more in-depth benchmarking than offered by traditional “whole-building” assessment methods. The process begins by carefully identifying a peer group for comparison that has true relevance to the subject building, and then disaggregating energy use by fuels and end uses to better pinpoint inefficiencies. Toward this end, the benchmarking process can be extended from energy to emissions and costs. Building characteristics and energy utilization parameters, as distinct from resource utilization data, can also be benchmarked in order to ascertain potential relevance and applicability of energy-efficient technologies or practices. To ensure savings attainment and persistence, benchmarking must continue throughout a building's lifecycle. A publicly funded web-based benchmarking system called EnergyIQ is introduced, which implements the aforementioned principals.

Factory eco-efficiency modelling

Purpose– This paper reports on the experimentation of an integrated manufacturing and building model to improve energy efficiency. Traditionally, manufacturing and building-facilities engineers work independently, with their own performance objectives, methods and software support. However, with progresses in resource reduction, advances have become more challenging. Further opportunities for energy efficiency require an expansion of scope across the functional boundaries of facility, utility and manufacturing assets.Design/methodology/approach– The design of methods that provide guidance on factory modelling is inductive. The literature review outlines techniques for the simulation of energy efficiency in manufacturing, utility and facility assets. It demonstrates that detailed guidance for modelling across these domains is sparse. Therefore, five experiments are undertaken in an integrated manufacturing, utility and facility simulation software IES < VE > . These evaluate the impact of time-step granularity on the modelling of a paint shop process.Findings– Experimentation demonstrates that time-step granularity can have a significant impact on simulation model results quality. Linear deterioration in results can be assumed from time intervals of 10 minutes and beyond. Therefore, an appropriate logging interval, and time-step granularity should be chosen during the data composition process. Time-step granularity is vital factor in the modelling process, impacting the quality of simulation results produced.Practical implications– This work supports progress towards sustainable factories by understanding the impact of time-step granularity on data composition, modelling, and on the quality of simulation results. Better understanding of this granularity factor will guide engineers to use an appropriate level of data and understand the impact of the choices they are making.Originality/value– This paper reports on the use of simulation modelling tool that links manufacturing, utilities and facilities domains, enabling their joint analysis to reduce factory resource consumption. Currently, there are few available tools to link these areas together; hence, there is little or no understanding of how such combined factory analysis should be conducted to assess and reduce factory resource consumption.

Estimating thermal performance and energy saving potential of residential buildings using utility bills

The objective of this study is to provide a practical method for estimating the energy saving potential of residential buildings using utility bills that are relatively easy to obtain from occupied buildings. The building characteristics and utility bills for three years, 2009–2011, were sampled from 128 apartment complexes, including 52,731 individual housing units. The utility billing data contain the monthly energy use of electricity, natural gas, and district heat for each complex. The energy uses of each complex were characterized using change-point linear regression models which described energy use as a function of monthly outdoor temperature and statistical parameters. The change-point models are statistically well fitted with actual monthly energy use, and the parameters of the models are capable of characterizing the energy use of residential buildings with hydronic radiant floor heating equipment. From the results, significant opportunities for space heating energy saving are identified in the sample complexes. The most sensitive and informative parameter for space heating energy saving is heating slope. The heating slope can represent the heat loss from the envelope and the efficiency of space heating. The method developed in this study can help to quantify the thermal performance of residential buildings, and also to identify the best type of energy efficiency opportunity.

Energy analysis of religious facilities in different climates through a long-term energy study

Buildings represent a large portion of total US energy usage. Religious facilities, which consume a significant percentage of the total floorspace and energy usage in the commercial sector, have generally not been the focus of efficiency studies or building energy audits. Religious facilities are characterized by unique patterns of occupancy and energy use. This paper presents the results of a long-term, in-depth energy study of architecturally similar church buildings in different climates in an effort to identify energy efficiency opportunities in religious buildings. Specifically, the paper details the experiment design and general usage trends from the buildings in different climates. A clear relationship between energy use and climate is evident, with HVAC and lighting systems consuming the majority of energy. An analysis on the prediction capabilities of using only a small subset of sensors to achieve similar results reveals the uncertainty of results by not metering all loads.

A Guide to Net-Zero Energy Solutions for Water Resource Recovery Facilities

The overall goal of this energy project is to aid water resource recovery facilities in quickly assessing their energy management performances (benchmarking) to move toward “net-zero” energy use through proven and available practices and technologies in the areas of energy conservation, demand reduction, and enhanced production. This project provides WERF subscribers with information on baseline energy performance for common wastewater treatment plant configurations and on opportunities for demand reduction, energy efficiency, and energy recovery/onsite energy production.The guiding principle behind net-zero energy was that neutrality had to be achieved by harnessing the energy contained in the wastes treated. Following this principle removed wind and solar power from consideration. These energy sources may contribute to a facility's energy performance, but they are unrelated to the embedded energy contained in waste streams at a water resource recovery facility (WRRF).The results from this project confirm the hypothesis that energy-neutral wastewater treatment is within reach for a significant number of facilities via proven and available technologies.This title belongs to WERF Research Report SeriesISBN: 9781780407685 (eBook)

Classification of Industrial Energy Management Practices

Environmental concerns, stricter legislation and inflated energy costs together yield improved energy efficiency as an important pillar in every industrial sector. Mindful of this challenge, energy management and its related practices are deemed to be one of the major instruments to improve energy efficiency within manufacturing companies. Despite the importance of this issue, there is no precise and unanimous definition for energy management practices. Moreover, very few papers investigate energy efficiency opportunities and/or energy management practices in foundry industry. This paper aims to identify, classify and characterize energy management practices through their definition, with respect to energy efficiency, that could take place in a foundry industry.

Energy efficiency opportunities in the production process of cast iron foundries: An experience in Italy

Foundry sector is one of the most energy intensive in industry. Energy audits performed in 5 Italian cast iron foundries allowed to identify energy utilization in the various processes that from the melting of the iron arrive at the finishing of the casting. Main equipment was surveyed, evaluating the influence on the overall energy consumption, producing a detailed analysis of energy use per department and energy performance indexes.A separate study was carried out for foundries with induction furnaces and cold or hot blast cupolas. Possibilities of heat recovery was identified particularly in combustion air preheating, but also for building heating or to power direct cycles to produce electricity. Better insulation and new insulating materials can improve the efficiency and the quality of the processes. Suggestions are supplied in the various foundry departments for energy saving.Possible energy saving actions on the service plants will be dealt with in a separate paper.

THE LIMITS OF IRRATIONALITY AS A RATIONALE FOR REGULATION

THE LIMITS OF IRRATIONALITY AS A RATIONALE FOR REGULATION

Evaluation of energy efficiency options in steam assisted gravity drainage oil sands surface facilities via process integration

While new technologies are being developed for extracting unconventional oil, in the near term economic benefits and footprint reduction can be achieved by enhancing the energy efficiency of existing facilities. The objective of this work is to evaluate energy efficiency opportunities for in situ extraction of Canada's oil sands resource using pinch analysis. Modifications to an original plant design are analyzed in order to estimate utility savings beyond those obtained for the initial process configuration. The modifications explored in this paper are estimated to deliver energy savings of up to 6% beyond ‘business as usual’. This corresponds to GHG emissions reduction of approximately 5%. However, in some cases, this increase in energy savings comes at the cost of increasing demand for make-up water and volume of disposal water. Surplus generation of steam beyond heating requirements in the water treatment system leads to energy inefficiencies. Additional cost and energy savings are obtained by reducing or eliminating the use of glycol in the cooling circuit.

Ant Colony Optimization for Load Management Based on Load Shifting in the Textile Industry

The textile industry is a complicated manufacturing industry because it is a fragmented and heterogeneous sector dominated by Small and Medium Enterprises (SMEs). There are various energy-efficiency opportunities that exist in every textile plant. However, even cost-effective options often are not implemented in textile plants mostly because of limited information on how to implement energy-efficiency measures. This paper presents the expansion of problem formulation of consummation management based on load shifting in textile industry. The mathematical model is a Non Polynomial (NP) hard optimization problem to determine the start time of the process in order to minimize the total electricity cost under varying tariffs such as flat rate and Time of Use (TOU). For solve this problem, Ant Colony Optimization (ACO) is applied and compared with Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). To show its efficiency, the case studies in case of Single Process Multiple Jobs (SPMJ) in term of small, medium and large scales are demonstrated. The results show that the proposed method is able to achieve the best solution efficiently and easy to implement.

The appeal of the green deal: Empirical evidence for the influence of energy efficiency policy on renovating homeowners

The Green Deal is a major new energy policy designed to support the diffusion of energy efficiency measures in UK homes. This paper provides one of the first empirical examinations of the Green Deal′s success in influencing homeowners’ renovation decisions. Using a repeated measures design in which households were questioned before and after the Green Deal′s launch in January 2013, we assess the policy′s success in raising awareness of energy efficiency. In particular, we test the effectiveness of the Green Deal′s positioning to overcome barriers to renovation among homeowners already interested in or considering energy efficiency measures. Using the innovation decision process (Rogers, 2003) as a conceptual framing of the renovation decision process, we examine whether new information on energy efficiency provided by the Green Deal strengthened intentions and its antecedents. We find that (1) energy efficiency is of potential appeal to all renovators regardless of their attitudes about energy efficiency, (2) energy efficiency opportunities need to be identified in the early stages of renovation when homeowners are thinking about ways to improve their home, and (3) homeowners’ intentions towards energy efficiency are weakened by uncertainty about financial benefits, helping to explain the relatively slow uptake of the Green Deal to-date.

Energy Efficiency and Recovery Opportunities Analysis for Municipal Wastewater Treatment Plant Operations

Energy Efficiency and Recovery Opportunities Analysis for Municipal Wastewater Treatment Plant Operations