Energy Performance Indicators Research Articles

Geospatial Analysis of Energy Poverty and Accessibility to District Heating Systems

This research paper undertakes a comprehensive geospatial analysis to investigate the relationship between energy poverty and district heating accessibility in Estonia. Utilizing ArcGIS Pro and statistical software, the study maps district heating systems, evaluates the energy efficiency of apartment buildings, and examines socioeconomic factors influencing energy poverty. By integrating GIS data with socioeconomic and building energy performance indicators, the research identifies areas where district heating is either absent or inefficient and correlates these findings with instances of energy poverty. Preliminary data may indicate a significant correlation between the lack of accessible district heating and increased energy expenses among lower-income households. The study also evaluates the impact of building energy efficiency on heating needs, revealing that older, less efficient buildings contribute disproportionately to energy poverty. Recommendations include policy interventions to expand and optimize district heating networks, alongside building renovation programs to enhance energy efficiency. This research contributes to the broader understanding of sustainable urban heating solutions and their role in mitigating energy poverty.

ENERGY MANAGEMENT SYSTEM (EMS) AS A TOOL IN LIMITING THE COAL TRACE IN INDUSTRY

Increasing energy efficiency will be crucial to achieving the climate goals laid out in European Uniondirectives. This is particularly true for industries whose share of heat and energy consumption,with Poland as an example, is about one-third of the total. This challenge entails implicationsboth for the reduction of greenhouse gas emissions, especially CO2, and for maintaining thecompetitiveness of EU industry on the global market. This article presents the basic principlesand application of an Energy Management System – EMS – in industrial processes, together withthe monitoring of Key Energy Performance Indicators – KPIs – as a tool for making informedinvestment decisions to improve the energy efficiency of companies and industrial processes. Anattempt is made to present the situation in Poland in terms of the energy situation, with a focus onthe automotive industry as an example.

Contextual operational energy performance indexing of district heating consumers

Energy performance indices are widely used methods for determining and assessing the efficiency of buildings in operation. However, methodologies for indices that compare heat consumption among buildings and at higher temporal granularity than yearly are needed. This makes it possible for consumers to compare themselves to others to encourage them to improve their energy efficiency. For a district heating system, it also provides the district heating company with an overview of consumers’ energy efficiency (and consumers’ efficiency must be comparable). This is critical due to the interconnectedness of district heating systems, as consumers can indirectly have negative impacts on each other’s operations. Having an overview of the efficiency of consumers can provide useful information for the district heating companies to detect unusual consumption and possible faults. This paper therefore has created a framework for the comparison of heat consumption among buildings, by taking into account various contextualities to make comparisons possible. The framework has been tested on a case study, and its capabilities are showcased.

A new approach for selecting and implementing phase change materials in Kuwaiti Buildings: Practical considerations

This study focuses on practical considerations regarding Phase Change Materials (PCMs) for energy-efficient buildings in Kuwait's hot climate. Its objective is to fill gaps in the existing literature by providing experimental validation, which has been lacking in previous research that heavily relies on numerical simulations. The selection of a PCM with an appropriate melting point is crucial to achieve balanced melting and solidification cycles. To address this, two identical portable cabins were constructed at the Australian University of Kuwait. One cabin served as the base case, while the other was used to investigate various energy-saving methods. Indoor weather and energy monitoring devices were installed, enabling the collection of wall and roof temperature data at 10-minute intervals. Analysis of the temperature distribution revealed that a PCM with a melting point of 24 °C remained in a melted state for approximately 8 h and solidified for 16 h within a 24-hour cycle, particularly on the hottest days in Kuwait. Furthermore, a TRNSYS Type399 PCM model was developed to examine the impact of PCM parameters on the annual energy performance index of the portable cabins. The results indicate that utilizing a PCM with a melting point of 24 °C on interior walls and ceilings can result in annual energy savings of up to 20 %, while the thickness of the PCM does not significantly affect performance. In a broader context, this research seeks to tackle the real-world challenges linked to the deployment of PCMs in energy-efficient buildings within Kuwait's hot climate. It highlights the significance of confirming findings through practical experimentation aimed at improving the utilization of PCMs.

A Novel Methodology for Developing an Advanced Energy-Management System

Current targets, which have been set at both the European and the international level, for reducing environmental impacts and moving towards a sustainable circular economy make energy efficiency and digitization key elements of all sectors of human activity. The authors proposed, developed, and tested a complex methodology for real-time statistical analysis and forecasting of the following main elements contributing to the energy and economic performance of an end user: energy performance indicators, power quality indices, and the potential to implement actions to improve these indicators, in an economically sustainable manner, for the end user. The proposed methodology is based on machine learning algorithms, and it has been tested on six different energy boundaries. It was thus proven that, by implementing an advanced energy management system (AEMS), end users can achieve significant energy savings and thus contribute to the transition towards environmental sustainability.

Evaluation of Energy Performance Indicators and Energy Saving Opportunities for the Italian Rubber Manufacturing Industry

The objective of this work is the energy characterisation and evaluation of the energy efficiency potential of the rubber manufacturing industry in Italy, exploiting the detailed data included in energy audits by large and energy-intensive companies. This sector is divided into two sub-activities: the manufacture of rubber products and the production of tyres. Existing studies are focused mainly on tyre production, and there is a lack of quantitative evaluation of energy indicators that can provide guidance for improving process efficiency. In this work, updated global and specific energy performance indicators (EnPIs) related to the production process and to the auxiliary and general services are defined and evaluated. At the same time, targeted actions and interventions to improve the energy efficiency of the sector are analysed, showing the role of different intervention areas and their cost-effectiveness. The analysis is based on 100 Italian mandatory energy audits of the sector collected according to Art.8 EU Directive 27/2012. The applied methodology made it possible to calculate specific energy performance indicators by considering the overall and sub-process energy consumption of different production sites. Based on a detailed database containing real data from recent energy audits, this study provides an up-to-date and reliable benchmark for the rubber industry sector. In addition, the analysis of energy audits allows the identification of the most effective energy efficiency interventions for the rubber industry in terms of cost-effectiveness and payback time.

Enhancing the energy efficiency of land vehicles air conditioning units through a new evaporative membrane cooler

Led by the growing need for energy efficiency in the air conditioning systems on land vehicles, this paper proposes an original approach that integrates evaporative cooling technologies into the existing systems. In detail, the new evaporative membrane system adds to the traditional one an auxiliary kit composed of a water reserve, a circulation pump, a heat exchanger, and an innovative capillary crossflow membrane cooler. The evaporation process is used to both pre-cool the air flow to the condenser, thus lowering the refrigerant condensation temperature, and also to supply refreshed water for pre-chilling the renewal air. The proposed architecture is particularly feasible for vehicular applications where a water reservoir already exists or where it is possible to install and maintain one. The designed membrane cooler grants high mass transfer efficiency, compactness (membrane surface-to-volume ratio around 1000 m2/m3) and manages high air flow rates while minimizing pressure loss. It is composed by organized layers of polypropylene capillaries where water flows, and plastic spacers for the airflow.First, the vapor and heat transfer mechanisms involved are investigated and the cooler’s mathematical model is described. Numerical results show that a wet-bulb effectiveness exceeding 0.85 can be reached.Subsequently, an assessment of energy performance indicators for a motorhome application is conducted within the MATLAB© Simulink environment. This involves a comparative analysis between the proposed system and the conventional standalone one. The considered contactor has a total membrane area of 8.32 m2 and handles 1200 m3/h of air and 150 kg/h of water. Results indicate that the efficiency ratio and the energy savings of the two systems decrease as the external air humidity increases even though the average energy efficiency ratio of the new system remains significantly higher. Mechanical energy savings are very interesting and decrease as the external air humidity increases: they are about 36–38 % within the humidity range [40–50 %], 26–30 % within the range [50–60 %], and 17–21 % within the range [60–70 %]. The corresponding water consumptions are between 2 kg/h and 6.5 kg/h, and they increase as air humidity decreases.Due to its simple architecture and high performance, this system is very promising in applications for motorhome, city buses, trains, and trucks.

Effect of PVA Fiber on the Mechanical Properties of Seawater Coral Sand Engineered Cementitious Composites.

The physical and mechanical characteristics of seawater coral sand engineered cementitious composites (SCECC) were examined through uniaxial compression, three-point bending, and splitting tensile tests. The mechanical properties were scrutinized under varying fiber volume fraction conditions (V = 0%, 0.575%, 1.150%, 1.725%, and 2.300%). The experimental results indicated that the compressive strength, three-point bending strength, and split tensile strength of SCECC tended to increase with the rise in fiber volume fraction. The strengths attained their maximum values of 45.88, 12.56, and 3.03 MPa when the fiber volume fraction reached 2.300%. In the compression test, the compressive strength of the 7-day specimen can achieve more than 78.50% of that observed in the 28-day specimen. Three-point bending test has revealed that SCECC exhibits favorable strain-hardening and multi-crack cracking characteristics. Fracture patterns of SCECC exhibited variations corresponding to changes in fiber content, as illustrated by their load-deformation curves, the addition of PVA fibers can change the damage mode of cementitious composites from brittle to ductile. The fracture energy of SCECC further attests to its elevated toughness. This is due to the fact that the fibers delay the formation of microcracks and prevent crack expansion, thus significantly increasing the deformability of the material. By verifying its strength, deformability, fracture energy, and other key performance indicators, the feasibility of SCECC in coastal construction projects has been clarified. The successful development of SCECC provides an innovative and high-performance option for the construction of future island projects.

Effectiveness of Three Reactor Chemical Looping for ammonia production using Aspen Plus simulation

This study uses Aspen Plus simulations to explore the performance of a new flowsheet for ammonia production using Three Reactor Chemical Looping (TRCL) technology. In TRCL, the solid Oxygen Carrier continuously circulates between a Fuel Reactor, a Steam Reactor and an Air Reactor. The Oxygen Carrier is reduced in the Fuel Reactor and oxidised in the Steam and Air Reactors. Hydrogen generated in the Steam Reactor and nitrogen produced from the Air Reactor form a synthesis gas that is converted to ammonia. This study compares the TRCL process with the conventional ammonia process and a pseudo-continuous Chemical Looping Reforming (CLR) process that uses packed beds. Energy and environmental indicators are evaluated for the three processes. It was found that the energy consumed in the TRCL process is higher than the other two processes because of higher steam consumption in the Steam Reactor for generating hydrogen. However, if conversion in the Steam Reactor of greater than 67.5% can be achieved, the energy performance indicators are comparable with the conventional and CLR processes. At 67.5% conversion, the specific energy consumption becomes 21.5 GJ/tNH3. It is also noted that the Specific Energy Consumption for Carbon dioxide Avoidance (SPECCA) is much better than the conventional ammonia process at a steam conversion higher than 67.5%. Although further development is needed, this study shows that TRCL holds promise for lower energy consumption and better environmental performance than other commercial ammonia production technologies.

Techno-economic, energy, and exergy analyses of invasive weed gasification for hydrogen enriched producer gas production

This research work deals with the examination of the techno-economic, exergy, and energy analyses of biomass gasification of the invasive weed Parthenium hysterophorus (PHP) using Steam - Carbon dioxide (CO2) as a gasifying agent with the support of simulation modeling for sustainable energy conversion process. The aim of this work is to simulate the gasification process through consideration of the impacts of various operating factors on gasification. This study attains the gradual increase in hydrogen (H2) concentration from 51% to 63% along with the rise in carbon monoxide (CO) from 14.5% to 19% using Aspen Plus simulation. CO2 falls concurrently from 24% to 13.5%. The findings demonstrate significant advancements over earlier studies in terms of both gas composition and overall system performance. A computational model has been developed for the estimation of energy performance indicators such as total energy input, and energy consumed per mass of biomass gasified, which are used in the determination of the system's energy efficiency. The exergy analysis of the system is performed to assess the system's total losses in terms of efficiency gathered from the system's exergy ratios. The economic analysis evaluates the system's economies of scale by gas production at ₹.15/kg and long-term sustainability. The proposed system has been found with the potential to produce a high yield of alternative energy from PHP with increased economic efficiency and lower environmental impact.

Performance of industrially implemented turbulent contact absorbers – A comparative study

The current study aims to assess the performance and industrial feasibility of using three-phase fluidized bed absorption columns for post-combustion carbon dioxide (CO2) capture. The analysis is based on a mathematical model of a scaled-up fluidized bed absorption column that has been validated using pilot plant experimental data. The focus is on evaluating the energy efficiency of the fluidized bed column in comparison to packed bed technologies, which are currently widely used. The results of the analysis are evaluated in terms of three performance indicators (i.e., absorption efficiency, carbon capture rate, and energy performance index) and compared to packed bed columns. Simulation results indicate that the best column configuration is represented by a three-stage absorber and that the system performs optimally when particle diameter and density decrease with each section. Consequently, this leads to an increase in the total fluidized bed height and carbon capture rate by up to 25%. The energy performance index is maintained below 3.6, indicating an energy-efficient operation of the system. As such, the findings of this study suggest that the use of gas-solid-liquid three-phase fluidized bed absorption columns for post-combustion CO2 capture is a promising technology for the implementation of CCUS and for achieving of climate neutrality targets.

Quadrotor Trajectory Control Based on Energy-Optimal Reference Generator

Inspired by the limited battery life of multi-rotor unmanned aerial vehicles (UAVs), this research investigated hierarchical real-time control of UAVs with the generation of energy-optimal reference trajectories. The goal was to design a reference generator and controller based on optimal-control theory that would guarantee energy consumption close to optimal with lower computational cost. First, a least-squares-estimation-(LSE) algorithm identified the parameters of the UAV mathematical model. Then, by considering a precise electrical model for the brushless DC motors and rest-to-rest maneuvers, the extraction of clear rules to compute the optimal mission time and generate ’energetic trajectories’ was performed. These rules emerged from analyzing the optimal-control strategy results that minimized the consumption over many simulations. Afterward, a hierarchical controller tracked those desired energetic trajectories identified as sub-optimal. Numerical experiments compared the results regarding trajectory tracking, energy performance index, and battery state of charge (SOC). A co-simulation framework consisting of commercial software tools, Simcenter Amesim for the physical modeling of the UAV, and Matlab-Simulink executed numerical simulations of the implemented controller.

Scenarios for the energy renovation of a residential building

In this paper, the results of the energy renovation of a residential building, aimed at introducing it into a Renewable Energy Community (CER), are presented. A case study located in Florence (Italy) is discussed. Static and dynamic energy models have been used to evaluate the energy performance of the building, to compare different scenarios based on heat pumps (independent or centralised generator) and to evaluate them under the perspective of EPBD parameters. A comparison has been made concerning energy consumption and CO2 emissions. In its current state, the building presents an energy performance index of 129.8 kWh/(m2year) (class D). The energy refurbishment with heat pump (A4, 24.7 kWh/(m2year)) and VMC system (A4, 39.3 kWh/(m2year)) ensures a strong reduction in CO2 emissions, respectively 5.5 kg/(m2year) and 8.7 kg/(m2year) against 24.4 kg/(m2year) with the current gas fired boiler. The centralized heat pump configuration allows to further reduce the energy consumption. With the same thermal energy requirement, the results show a reduction of 14% of the power needs (without total recovery), thanks to the better sizing of the generator. Furthermore, the centralized heat pump opens a perspective of direct self-consumption of the energy product by the photovoltaic system into a CER configuration. The paper shows that the energy renovation with a heat pump is an effective way to reach the EPBD objectives and decarbonize the residential heating and cooling sector.

Effect of ENS Code Compliance on Performance of Building with Respect to Energy Performance Index

Effect of ENS Code Compliance on Performance of Building with Respect to Energy Performance Index

Techno-economic assessment and grid impact of Thermally-Integrated Pumped Thermal Energy Storage (TI-PTES) systems coupled with photovoltaic plants for small-scale applications

The growing share of Renewable Energy Sources (RES) is rising the amount of curtailed energy to preserve grid security. With the aim of evaluating a complementary storage solution to electric batteries for both new and revamping RES power plants, this study investigates the performance of a Thermally Integrated Pumped Thermal Energy Storage (TI-PTES) system integrated with a Photovoltaic (PV) power plant aimed to enhance the energy self-sufficiency of small-scale users. The assessment is carried out for a case study characterized by a demand of electricity, heating and cooling that vary throughout the year. The studied PTES system is based on the integration of a High Temperature Heat Pump (HTHP), two Thermal Energy Storage (TES) sections and an Organic Rankine Cycle (ORC) power plant. Results show the influence of the main design parameters, such as PV size, HTHP size and TES capacities on the overall system performance, evaluated by means of the energy self-sufficiency, energy self-consumption, round-trip efficiency, Levelized Cost of Storage and the Grid Impact indicator, which quantifies the energy exchanges with the grid (feed-ins and withdrawals) to the overall user demand. The influence of seasonality on the energy performance indicators was studied as well. For the case study considered, the best combination of design parameters for the PV-PTES system is identified with reference to a PV plant whose yearly energy production equals the energy demand and for a 55 kWe High Temperature Heat Pump, a 10 kW ORC and a storage volume of 48 m3 for each of the two TES units. The PTES system is characterized by a LCOS of 0.72 $/kWh, a round-trip efficiency of 28.2 % and its integration offers several advantages over the use of a PV plant without any storage section. In particular, the PTES unit leads to a substantial increase in the self-sufficiency, within the range 1–14 %, and a considerable decrease of the grid impact indicator, within the range 2–28 %.

Assessing energy efficiency at urban scale through the use of energy performance certificates: An application in the Emilia-Romagna region, Italy

Energy retrofitting of residential buildings is considered a challenge to be tackled not only at building level, but also at urban scale, to give a stronger impulse for a concrete transition towards climate neutrality. This paper presents an easy-to-use analysis method based on the elaboration and scaling-up of data collected through the energy performance certificates (EPCs) to identify different urban energy zones distinguished by their energy performance index. This method is therefore conceived for better informing urban planning decisions, thus boosting more effective energy-sensitive urban planning strategies and eventually to foresee dedicated financial instruments to act in the more energy demanding areas of the city, establishing priorities for integrated strategies. This analytical method has been applied and tested in one municipality in the Emilia-Romagna region, Italy, where the recent urban planning law is pushing municipalities towards the development of urban planning strategies oriented to drastically improve the energy efficiency of the existing building stock. Results show that only a small number of areas manage to reach a good performance with fairly low levels of energy performance index, with the most critical situation found in the most central areas of the capital and in the hamlets.

Fractional Guidance Law with Impact Angle Constraint and Seeker’s Look Angle Limits

In this paper, using fractional mathematics, the guidance law of collision angle control is proposed by simultaneously taking into account the limitation of the seeker’s look angle. In order to apply the limitations of impact angle and launch in the equations of the acceleration command, the movement path from the time of launch to reaching the target is divided into three phases, and for each phase, a specific acceleration command is applied to the pursuer whose rules are based on optimizing and minimizing the control energy performance index with the weighting function obtained from range-to-go. The progress of the movement path and the parameters of the guidance law are compared with each other by passing three phases of the follower’s movement path with a constant speed for a fixed target in two cases of fractional and integer order.

Energy efficiency assessment in collective irrigation systems using water and energy balances: methodology and application

AbstractMany collective irrigation systems have been operating for decades, facing high degradation of existing infrastructures and huge water-energy efficiency problems. Predominantly composed of open canals, they have been partially or entirely converted into pressurised pipe systems, implying a considerable increase in energy consumption and operation and maintenance costs. Simple, easy-to-use, and comprehensive approaches for energy efficiency assessment in collective irrigation systems are needed for diagnosis and assisting decision-making on implementing adequate improvement measures. This research proposes and demonstrates an innovative approach based on the water and energy balances and performance indicators to assess the effect of water losses, network layout and operation, energy recovery, and equipment on energy efficiency. A novel methodology for energy balance calculation is proposed for open canal, pressurised and combined systems. The application to a real-life open canal system and network areas allowed the identification of efficiency problems mainly due to water losses in canals, followed by the dissipated energy in friction losses. Less critical are pumping and manoeuvring equipment inefficiencies. Also, a considerable excess of gravity energy is recovered in hydropower plants. In raising pipe systems, in which shaft input energy predominates and costs for pumping play a key role, surplus and dissipated energy in friction losses are the most relevant issues. Significant energy is lost in the water conveyance and distribution in both systems. Consequently, the potential to improve energy efficiency through water loss management, network layout, and operation improvement, besides pumping and manoeuvring equipment replacement, is considerable.

ENERGY PERFORMANCE INDICATOR FOR HEALTH CARE BUILDING: A CASE STUDY OF A SMALL SIZED HOSPITAL IN INDONESIA

Energy is needed to guarantee the reliable and safe operation of healthcare buildings. The hospitals and other healthcare building energy performance have been investigated using several sets of energy performance indicators (EnPIs) formulation in several contexts. Often, those EnPIs are meaningless compared to other healthcare buildings, or they are restricted in their ability to guide energy investment planning or operation. This study examined four approaches—kWh/sqm/year, kWh/bed-day, kWh/overnight inpatient, and kWh/sum of inpatient and outpatient—for calculating EnPIs of a small-sized government hospital. The analysis focused on methods for defining EnPIs in the healthcare industry. With a value of 4.62 kWh/patient, it was found that the kWh/sum of in and outpatient was the optimal EnPI model.

A pragmatic retrofitting approach to enhancing the thermal, energy and economic performance of an educational building: a case study in Malaysia

Abstract Building retrofit procedures play a crucial role in improving the energy performance and economic indicators of a building. In this context, an energy audit is typically recommended, but it is seldom used as a comprehensive approach due to the complexity and associated costs. This article aims to conduct a holistic energy audit approach for a university building in Malaysia, with the objective of diagnosing energy efficiency deficiencies, identifying areas of energy waste and proposing practical retrofit measures accordingly. The approach involved multiple stages, including measurements, surveys and simulation work. Eight energy-saving measures were proposed, targeting improvements in envelope elements, cooling and lighting systems, and operation and control. The Design-Builder software was utilized for energy simulation, assessing the annual energy savings. Economic evaluation indices, such as net present value and simple payback period, were used to assess the economic feasibility of the measures. The results demonstrated significant potential for energy reduction, with each measure achieving annual energy reductions ranging from 2% to 18%, and a cumulative impact of 41% on annual energy consumption when combined. The investment payback period for the energy-saving measures varied from 0.8 to 8.9 years, with a payback period of 3.9 years for the combined energy-saving measures. Furthermore, the net present value was positive, indicating the economic feasibility of investing in the proposed energy-saving measures. These findings provide valuable energy-saving opportunities that can be applied to improve similar buildings on the university campus.