Energy Efficiency Indicators Research Articles

Environmental Benefits of Catch Crops Cultivation

Abstract The role of catch crops in modern agriculture has increased in recent years. In addition to a production of animal feed, they have a positive impact on quality of soil. This study determined the suitability of selected stubble catch crops (white mustard, lacy phacelia, and a mixture of faba bean + spring vetch) to improve production, economic and energy effects of spring wheat grown in 3-year monoculture relative to the control treatment (without catch crops). Two tillage systems were used: conventional tillage and no-tillage (conservation tillage). A field study was conducted over the period 2014-2016 at the Czeslawice Experimental Farm, Lubelskie Voivodeship, Poland. The study proved the high suitability of catch crops to increase the spring wheat yields (under both tillage systems). Regardless of the catch crops, the productivity of wheat was higher under conventional tillage. The catch crops (in particular white mustard) and the conservation tillage system contributed to an improved energy efficiency index of production. The white mustard catch crop also had the most beneficial effect on the economic profitability of spring wheat production. This was due to the low cost of cultivation of this catch crop and its beneficial impact on obtaining high yields of spring wheat.

SA-LSTMs: A new advance prediction method of energy consumption in cement raw materials grinding system

Electricity consumption is a major energy efficiency indicator in cement raw materials grinding system. Advance prediction of electricity consumption provides the basis for cement production scheduling and achieves the energy saving. However, due to the influence of strong coupling, delay, intrinsic non-linearity and uncertainty, it is difficult to model the raw materials grinding system accurately. To address this problem, a new model of long short-term memory networks based on spatial attention is proposed in this paper. The proposed method uses LSTM neural networks appropriately to capture the long-term temporal dependencies of the system variables appropriately to solve the problem of time delay. Spatial attention is designed to improve the spatial perception of the model and increase the sensitivity to important information. Thus, the proposed method can efficiently capture the temporal and spatial characteristics of the cement raw materials grinding system. In addition, to verify the superiority of the proposed method, we introduce LSTM, Seq2Seq, ARIMA, SVM and XGBoost for comparison. The experimental result confirms that the proposed model achieves the highest performance, which provides an encouraging perspective for real-time energy consumption prediction in raw materials grinding.

Energy consumption and energy efficiency trends in Singapore: The case of a meticulously planned city

Singapore is a small island-state and meticulously planned city. The lack of energy resources has underpinned its unwavering focus on energy efficiency. Yet to date it is unclear to what extent energy efficiency, or the so-called “hidden fuel” or “invisible fuel”, has contributed to reductions in its energy consumption. Using a comprehensive and unique set of energy and sectoral activity data, this study applies the energy intensity concept and index decomposition analysis technique to study the role of energy efficiency in reducing Singapore's energy consumption from 2005 to 2018. The results obtained show variations across energy consuming sectors, but overall energy efficiency has led to significant energy savings. A composite energy efficiency index is also constructed to quantify the extent of energy efficiency improvement economy-wide over time. The performance as captured by this index shows a slower rate of improvement as compared to that given by the reduction in Singapore's aggregate energy-to-GDP ratio. This development is similar to that observed in most OECD countries. The framework developed can be applied to the study of other major cities especially those in Southeast Asia. It should be noted that, while the approach used has been widely accepted in the energy efficiency literature, the energy efficiency trends derived are dependent on the activity indicators chosen to represent the useful work performed in the respective sectors. The results should therefore be interpreted in this context.

Thermoeconomical optimization of a regenerative air turbine cogeneration system

The concept of optimization of operating and design parameters of the regenerative air turbine cogeneration (RATC) system is proposed. To determine the energy efficiency indicators of this system, its thermodynamic analysis was performed. At the same time, it is shown that it is not correct to search for the optimal parameters of such a system only by energy indicators, and modern thermoeconomic methods should be more actively involved in pre-design practice, which allow a comprehensive evaluation of the efficiency and economy of the energy-technological system as a whole and its individual elements. Therefore, on the basis of the data obtained during the thermodynamic analysis, exergy destruction and losses in the main system elements were calculated. Then, using the structural-variant method in combination with the graphical apparatus of C-curves, the pre-project thermoeconomic optimization of the RATC system was performed. This made it possible to choose the optimal operating and design parameters of the system and determine the minimum cost for its creation and operation throughout the entire life cycle, taking into account the thermodynamic perfection of the main system elements. Each variable operating mode parameter of the system serves as a kind of navigator when searching for the option of system parameters that is optimal in terms of energy and economic indicators, which is accompanied by graphic visualization. Therefore, the proposed approach makes the optimization of the system being designed convenient and clear. It can be used in the optimal design of various types of thermal transformers and other energy-technological systems.

Trade policy uncertainty and improvement in energy efficiency: Empirical evidence from prefecture-level cities in China

In the face of the shocks from trade policy uncertainty (TPU), China needs to improve urban energy efficiency (EE) to achieve its “carbon neutrality” goals as scheduled, but the existing literature has no systematic research on this topic. This paper develops and estimates TPU and EE indexes by adopting the Bartik instrument's methods and dynamic slacks-based measure (DSBM). Furthermore, the authors conduct empirical tests on the influencing effect and transmission mechanism of falling TPU on urban EE after the US granted China permanent normal trade relations (PNTR) status in 2001 with a difference-in-difference (DID) model. The results of the empirical study show that urban EE improves by around 1.9% when TPU falls by 1%. A heterogeneity analysis also shows that a falling TPU has a more significant impact on EE in provincial capitals, open cities, “hygienic cities,” highly marketized cities, and cities with a higher share of manufacturing. Falling TPU reduces the cost of foreign capital inflow into China. It drives progress in green technologies, thus improving urban EE by replacing energy factors with innovation-driven non-energy factors. Further, export expansion and export technology complexity significantly raise the stimulating impact of falling TPU on improvement in EE, but growing processing trade impedes this impact. The findings in this study offer a new perspective on estimating the effect of China's policies to respond to global climate change against the shock from TPU and provides new evidence for strengthening global energy cooperation.

Data Envelopment Analysis and Analytics Software for Optimizing Building Energy Efficiency

This research was motivated by the need to identify the most effective Data Envelopment Analysis (DEA) model and associated data analytics software for measuring, comparing, and optimizing building energy efficiency. By analyzing literature sources, the authors identified several gaps in the existing DEA approaches that were resolved in this research. In particular, the authors introduced energy efficiency indices like energy consumption per square foot and per occupant as a part of DEA models’ outputs. They also utilized inverse and min-max normalized output variables to resolve the issue of undesirable outputs in the DEA models. The evaluation of these models was done by utilizing various data analytics software including Python, R, Matlab, and Excel. The authors identified that the CCR DEA model with inverse output variables provided the most reliable energy efficiency scores, and the Python’s PyDEA package produces the most consistent efficiency scores while running the CCR model.

Energy Efficiency Indicators for Water Pumping Systems in Multifamily Buildings

With the current concerns about sustainable development and energy consumption in buildings, water pumping systems have become essential for reducing energy consumption. This research aims to develop guidelines for the energy assessment of water pumping systems in multifamily buildings. The methodological procedures are: (i) definition of the efficiencies of electric motors; (ii) definition of pump efficiency levels; (iii) determination of energy consumption; and (iv) construction of the efficiency scale and guidelines for projects and assessments. The results obtained were that centrifugal pumps with 40% efficiency have higher energy consumption, regardless of the efficiency class of the electric motors, showing a 20% increase in electrical energy consumption. Lower efficiencies directly impact the energy efficiency rating of the water pumping system. Thus the 40% efficiency obtained energy efficiency rating “Very Low—VL” for all motor efficiency classes (between IE1 and IE5). At 60% efficiency, the energy efficiency level of the system was “Average—A”, gradually increasing to “Very High—VH”, as the energy consumption in the pumps decreased and the motors’ energy efficiency classes increased. It is concluded that designers and professionals in the area must consider the efficiency of the pumps, as they play a fundamental role in the classification of the system’s energy efficiency. It is also recommended to verify the energy efficiency of the water pumping system and implement design guidelines so that the pumping system achieves lower energy consumption, contributing to the building’s energy efficiency and sustainability.

The Effectiveness of Extended Schedules of Heating Regulation at CHP Plants with Decreasing Normative Design Temperature of the Supply Water

The aim of the work is a computational study of the effectiveness of the extended schedules of heating regulation at steam turbine CHPPs with a decrease in the normative design temperature of the supply water. The study was carried out on adequate mathematical models of CHP tur-bines and heat supply systems, considering heat pipelines' actual diameters and lengths. The main energy efficiency indicator is the specific reference fuel consumption for electricity sup-ply, calculated under comparable conditions for the operating modes of turbine plants and the load of the heat supply system. The study took into account the electricity consumption for the drive of network pumps, standard heat losses in heating networks and the electricity generation for the heat consumption of CHPPs. The study results allowed for the first time to determine the integral indicators of the energy efficiency of work during the transition of CHPPs from the normative design ones to the temperature schedules reduced by the temperature of the supply water. At the same time, the calculations revealed the limitations on the parameters of the extended schedules of regulation when transitioning to reduced temperature schedules. The most important results of the work should also be attributed to the determination of the optimal schedules of the temperature of the supply water for different values of the district heating coef-ficient of the CHPP. The results obtained are essential for assessing the efficiency of the transi-tion of heat supply systems to reduced supply water's design temperatures when using modern heating regulation schedules.

Ефективність використання стимуляторів і регуляторів росту під час вирощування біомаси міскантусу в умовах лівобережного лісостепу України

The article presents the indicators of economic efficiency of growing miscanthus biomass for the production of solid biofuels. The energy efficiency coefficient is calculated as the ratio of energy input to energy output. The aim of the study was to assess the efficiency of the use of plant growth-promoting and regulating products Vympel-K and Quantum-Gold in the cultivation of miscanthus biomass in the Left-Bank Forest-Steppe of Ukraine. Results. Return on investments starts since the third year of harvesting. The gross income after the fourth vegetation season was 392 900 UAH per hectare. The highest energy efficiency index (4.2−4.4) calculated for the first-year harvest was in the following treatments: single and double dose of NPK, single and double treatment with Vympel-K. Profitability in these treatments was the highest and ranged from 345.3 to 341.4%. The proposed new component of cultivation technology − soaking the rhizomes before planting in the growth-regulating and promoting products Quantum Gold and Vympel-K is economically justified. The return on investments after the sale of the miscanthus biomass for the use of these techniques starts since the third year of cultivation.

Conceptual design and assessment of a novel energy management system for LNG fueled ships with air separation

Medium and large ships always need to carry many different types of gas cylinders. Limited by the hull, their gas storage is small, restricting the ship's ocean voyage time. It is the most effective solution to use the air separation device and cabin air to prepare various purified gases on site. However, the traditional cryogenic air separation system has large energy consumption and low efficiency, which is not suitable for shipboard use. Therefore, this paper innovatively proposes the air separation systems for the cold energy utilization of onboard LNG-powered ships. According to the characteristics of ship engine power and pressure ratio change of LNG fuel supply system, LNG energy management systems (LNGEMSs) with high and low pressure matching cold energy utilization air separation unit processes are proposed and compared. The exergetic analysis model of the design was established using pinch point analysis, energy balance methods, and energy efficiency indexes. The applicability conclusion was determined through actual onshore process verification, comparison, and exergy analysis. The cryogenic air separation system on LNG fueled ships can adopt a different pressures heat exchange network solution to make full use of LNG cold energy to improve energy efficiency. The LNG cold exergy efficiency of the LNGEMSs can reach 83.2%, and the unit liquid product energy consumption is only 0.225 kWh·Nm−1. Due to the additional means of energy conversion and utilization, the ship design and operating indexes with the new system meet or exceed the current regulations and the current technical level. Additional oxygen obtained by air separation can further improve the combustion efficiency of marine gas turbines, which brings good prospects for marine air separation technology.

The concept of an integrated system of energy efficiency control of artifical oil lift

THEPURPOSE.To consider the problems of controlling the energy efficiency of artificial oil lift. To conduct a comparative analysis of the approaches used to assess the level of energy efficiency and the possibility of energy saving. To submit to a modern possible energy efficiency control system. To identify an effective method for verifying energy efficiency indicators. To propose a concept of an automated control system for energy efficiency of artificial oil lift based on intelligent methods of data analysis.METHODS.Whensolvingtheproblem,themethodoffactoranalysisofspecificpowerconsumption,implementedina model, was used.RESULTS.Thearticledescribestherelevanceofthetopic,considersthefeaturesoftheuseofvariousindicatorsofenergyefficiency.A model of factors for specific power consumption has been developed. In this article, a concept of an automated energy efficiency control system based on intelligent methods has been proposed.CONCLUSION. Usingtheindicatorofspecificelectricityconsumptionforartificialoillift,asanindicatorofenergyefficiency,makesitpossibletoassessthecurrentlevelofenergyefficiencyandidentifythepotentialforfurtherenergysaving.To control the specific consumption of electricity at the mechanized stock of production wells, it is necessary to implement systemic energy metering, additional factor analysis of deviations from the planned values. Using of intelligent methods of data analysis selects the factors of deviation of the specific power consumption and ensures the reliability of energy efficiency control.

RESEARCH OF ENERGY LOSS IN A SOLAR POWER PLANT AT A TRACTION SUBSTATION

An analysis of losses in a solar power plant of direct current № 18 с. Zmiiv, Kharkivregion with all climatic conditions of this region. The energy efficiency indicators of inverters used in these solar power plants are analyzed. According to experimental data based on the softwarepackage PVsyst measured energy losses generated by a solar power plant. Connecting the SES to themains can improve the voltage levels at the system nodes, but it is necessary to provide a powerreserve in the system to cover the power deficit in the event of a sudden shutdown due to naturalfactors.To analyze the energy losses of solar energy, the software package PVsyst was used, whichallows you to analyze the parameters of electricity losses with the display of loss diagrams for theyear and the dependence of the amount of losses in electricity generation by solar panels. PVsystsoftware is used to calculate the output power, performance, and total loss of a station connected tothe network. Losses calculated by PVsyst software include two types: PV array loss and System loss.After analyzing research conducted in Ukraine and other European countries, it is possible toconclude that the impact of poor quality electricity on electrical equipment is quite significant, andthe study of the impact of unconventional generation sources on electricity quality indicators willidentify ways to reduce electricity losses and increase electricity life equipment. The efficiency ofsolar energy conversion is greatly reduced due to reflections from the surface of the photovoltaicsystem. Also due to the peculiarities of the construction of photovoltaic converters there is a decreasein the efficiency of solar panels with increasing temperature.

DEVELOPMENT OF POSSIBILITIES OF THE METHOD OF INDIVIDUAL COMPONENTS FOR ANALYSIS OF MODES IN ELECTRICAL SMART- COMPLEXES


 
 
 The peculiarities of the formation of the local power system according to the concept of Smart Grid requires a qualitatively new architecture of the power supply system and new principles of operation - both at the level of technical solutions and mechanisms of organizational interaction at the technological level and financial calculations. The scientific and technical problems connected with functioning of separate types of electrotechnical Smart-complexes (ETK-Smart) are analyzed, features of the analysis of electrotechnical complexes with nonlinear elements by the analysis of processes in case of changes of active and reactive loadings that allows to consider corresponding changes of parameters at calculations of electromagnetic processes using analytical methods. The methodology for assessing the impact of conductive periodic interference on the flow of the steady state in electrical Smart-complexes has been improved. The principles of analysis (modeling) of ETC- Smart as systems with periodically changing parameters are considered. It is shown that the use of ETC-Smart requires meticulous attention to the analysis of steady-state and transient, including modulated, modes, in the case of formation of different schedules of energy and technological processes, power supply of various types of loads, etc. Algorithms for calculating currents in electrical complexes with cyclically variable parameters, as well as analysis of the influence of periodic conductive interference in ETC-Smart elements with power converters based on the development of the capabilities of the method of individual components in modeling steady-state modules. Thus, algorithms for analysis of electromagnetic processes in ETC-Smart with variable parameters and RL-load for complex periodic, system analysis in case of nonlinear elements, analysis of internal resistance of generator and transmission lines, analysis of processes in abrupt change of parameters of reactive elements (inductance L) and capacitance C), analysis of the influence of periodic conductive interference (AC and DC) on electromagnetic processes in the elements of ETC-Smart with power converters The basics of methodological support for assessing the energy efficiency of ETC-Smart as elements of intelligent power supply systems are presented. The algorithm of electrotechnical inspection (energy audit) of electrotechnical complexes by application of the offered analytical expressions and the generalized algorithm of calculation of electromagnetic processes in electric complexes with cyclically variable parameters is offered that allows to carry out the corresponding estimations of energy efficiency of functioning. The concept of formation (construction) and modernization of optimization of elements of Smart-technologies for the Smart-microdistrict of the intellectual city by development of algorithm of realization of the corresponding researches and estimations and formation of the Microgrid network (ETC-Smart with power converters) of several levels of hierarchy is offered. and assessment of the general energy efficiency indicators of the Smart-microdistrict of the intellectual city. The presented examples of analysis confirm the effectiveness of the modification of the method of individual components for the analysis of steady-state ETC-Smart.
 
 

Energy Balance in Wastewater Systems with Energy Recovery: A Portuguese Case Study

This paper presents and discusses the application of a novel energy balance scheme for assessing energy efficiency in wastewater systems. The energy balance is demonstrated with a Portuguese real-life case study, using mathematical modelling to estimate the different energy components and to compute two energy efficiency indices. The total inflow intrinsic energy can represent a significant amount (>95%) of the total energy used in systems mainly composed of gravity sewers. The total input energy is significantly (four-times) higher in the wet season than in the dry season, mostly due to undue inflows (e.g., direct rainfall and infiltration). The potential for energy recovery strongly depends on the available head and flow rate at the delivery point, being 0.01 kWh/m3 in the current case, with a project payback period of 4 years. The energy balance components and the respective energy efficiency indices strongly depend on the considered reference elevation. Thus, a unique regional reference elevation is recommended in the calculations.

An energy efficiency index for elastic actuators during resonant motion

AbstractThe energetic advantages of series and parallel elastic actuators have been characterized in the literature considering different elastic systems and different tasks. These characterizations usually determine the energy consumption of a specific system during a specific task and generalize poorly. This paper proposes an energetic characterization of elastic actuators, following an analytical approach, rather than a data-driven one. In particular, this work analyzes the energy consumption of elastic actuators during resonant motion and introduces a novel efficiency index. This index characterizes energy consumption as a function of inherent actuator parameters only, generalizing over the specific tasks. The proposed analysis is validated using simulations and experiments, demonstrating its coherence with analytical results.

Energy-efficient variable frequency asynchronous electric drive

Currently, there are quite a large number of various scientific papers on the creation of a controlled asynchronous engine and the optimization of its modes, and the availability of acceptable results for practical implementation, but there is still no single generally accepted approach to solving the problem. In this regard, the issue of synthesis of scalar control systems that provide the minimum value of one or another criterion of energy efficiency is relevant. In this paper, we consider the obtained mathematical model of an asynchronous engine (AE), which differs from the known ones in that the parameters of the substitution scheme are expressed in terms of the stator and rotor conductivities. The energy characteristics of the AE in the sliding function are obtained, which make it possible to determine the dependences of the active and reactive components of the AE current and the possibility of their redistribution within the nominal value of the AE phase current. The principle of optimal frequency-current control of AE is formulated, which differs from the known ones in that, as an energy efficiency indicator, the value of the maximum energy efficiency of AE is used, expressed as the ratio of the active resistance of the rotor circuit to the total conductivity of the AE phase.

Grazing beef cows identified as efficient using a nutrition model partition more energy to lactation

Context The efficiency of the cow–calf sector could be enhanced by matching cow biological type to the production environment; however, methods to estimate the biological efficiency of grazing beef cows are not available. Aims This study utilised a mathematical nutrition model for ranking beef cows for estimated biological efficiency, determining energetic efficiency and evaluate relationships with other production traits. Methods Cow live weight, calf birth and weaning weight, calf birth and weaning date, and forage nutritive value of hay and pasture were collected for 69 Brangus crossbred beef cows over a complete production cycle. The Cattle Value Discovery System for Beef Cow (CVDSbc) model was used to compute metabolisable energy required (MER) for the cow, and energy efficiency index (EEI) was computed as the ratio of MER to calf weaning weight. Pearson correlation coefficients were computed among performance traits. During late lactation and gestation, low (n = 8) and high (n = 8) EEI cows were individually fed ad libitum for 44 and 32 days, respectively, then fed 0.5× the estimated metabolisable energy required for maintenance for 7 days (gestation experiment only). Apparent nutrient digestibility, heat production, and milk yield were measured. Key results EEI was strongly negatively correlated (P < 0.05) with model predicted peak milk (−0.62) and calf weaning weight (−0.65), but moderately correlated (P < 0.05) with cow live weight (0.46). Dry matter intake was not different (P > 0.75) between low and high EEI cows even though low EEI cows weighed less (P < 0.05) during late lactation and gestation experiments. Low EEI cows tended to have greater efficiency of metabolisable energy use for maintenance and gain (P < 0.10), and EEI was negatively correlated (P < 0.05) with the efficiency of metabolisable energy use for maintenance (−0.56) and gain (−0.57). Conclusion The CVDSbc model identified cows that weaned heavier calves due to greater dry matter intake of cows relative to live weight allowing more energy apportioned towards lactation, and more efficient use of metabolisable energy for maintenance and gain. Implications Energy efficiency index might provide a logical assessment of biological efficiency of beef cows in grazing production systems.

An Experimental Study Towards Decreasing the Energy Efficiency Index Value in Industrial Refrigerators

Energy labeling is performed according to the energy efficiency index (EEI) value in industrial coolers. In order to reduce the EEI value calculated according to the amount of energy consumed and the characteristics of the cooler. Two systems were designed in this study and the energy label class of the coolers was determined according to the obtained results. In this study, two different coolers (Type 1 and Type 2) were designed, manufactured and tested. The systems are designed using R290 (propane), a new generation natural and environmentally friendly refrigerant with two inlet-outlet evaporators, double condensers and double compressors to provide a homogeneous cooling. During the experiments, temperature-pressure measurements of the cooled products and cooling system equipment were taken from certain points every minute and test data were recorded. In the experiments, the average air temperature and relative humidity values of the test chamber of the experiment with resistance glass in the Type 1 cooler were measured as 25 ℃ and 59.09%, respectively, the average air temperature and relative humidity values of the test room of the Type 2 system experiment with antifogging film were measured as 25.231 ℃ and 57.207%, respectively. In the experiments, defrosting process was carried out twice a day in the coolers. During the experiment, the highest and lowest average temperatures of the cooled products were measured as -16.18 ℃ and -19.40 ℃. Increasing product temperatures during defrosting and stopping cooling increased the power consumption in the system. As a result of the calculations, the energy efficiency index value of the Type 1 resistance model was calculated to be 60.53 and it was seen that the energy label was class “E”. In the Type 2 model in which anti-fog coating film is used, the energy efficiency index value is 49.25 and it has been observed that the energy label is class "D".

On the Road to a Green Economy: How Do European Union Countries ‘Do Their Homework’?

Multidimensional crisis phenomena (financial–economic, environmental and social), plaguing the international community, especially in the last 30 years, have intensified resentment towards traditional models of growth and socio-economic development. The European Commission has placed the idea of a green economy (GE) at the heart of the Europe 2020 strategy. This paper presents an assessment of the implementation of the green economy assumptions in EU countries in 2018, taking 2010 as the base year. Using taxonomic methods, a synthetic evaluation index (GEI—Green Economy Index) was constructed based on a multi-criterion set of 27 indicators. This paper attempts to answer the following questions: How green are the European economies? What are the main challenges in this context? The average value of the index for the EU countries decreased in the studied years from 0.3423 to 0.3294, which can be interpreted as a slowdown in the greening processes. The key recommendations for the upcoming years include the improvement of energy efficiency indicators, the further increase in the share of renewable energy sources in the energy balance. Moreover, a significant problem continues to be the high percentage of the population at risk of poverty or social exclusion, as well as low CO2 and resource productivity rates.

Energy consumption as an indicator of energy efficiency and emissions in the European Union: A GMM based quantile regression approach

Energy efficiency can boost economic growth and reduce greenhouse gas (GHG) emissions. However, the global rate of energy efficiency improvement is slowing – a trend that has implications for consumers, businesses and the environment as the adverse climate change and pollution impacts deepen. The emissions in the EU have decreased by 17% in the past decade while member countries such as Germany, United Kingdom and Poland were among the largest emitters of CO2. This paper examines the effect of energy efficiency, proxied by final energy consumption, on CO2 emissions in the EU using a generalized methods of moments based on a quantile regression approach. We use the Panel Quantile ARDL for inference at various quantiles and support the ARDL estimations by the 2SLS estimations for robustness checks. We use the final energy consumption data as an indicator of energy efficiency as included in the energy efficiency indicators database of the International Energy Agency and emissions for the time period spanning 1980–2018. The results indicate that energy efficiency has reduced emissions by 8.6% on average in all the quantiles. Improving efficiency in petroleum consumption will enable the EU to reduce emissions as well as improve energy security by reducing imports as per the aims of the European Green Deal and the Efficiency First Principle. We also recommend that energy efficiency policies should account for possible rebound effects, which can limit their effectiveness.