Annual Electrical Energy Consumption Research Articles

Geothermal Heat Pump for Space Cooling and Heating in Kuwaiti Climate

Kuwait stands as one of the hottest locations globally, experiencing scorching temperatures that can soar to 50 °C during the summer months. Conversely, in the winter months of December and January, temperatures may plummet to less than 10 °C. Maintaining a comfortable temperature indoors necessitates a substantial amount of energy, particularly during the scorching summer seasons. In Kuwait, most of the electrical energy required for functions such as air conditioning and lighting is derived from fossil fuel resources, contributing to escalating air pollution and global warming. To reduce dependence on conventional energy sources for heating and cooling, this article presents a case study to explore the potential of using geothermal energy for space heating and cooling in Kuwait. The case study involves utilizing a geothermal heat pump (water-sourced heat pump) in conjunction with a vertical-borehole ground heat exchanger (VBGHE). The mentioned system is deployed to regulate the climate in a six-floor apartment block comprising a small two-bedroom apartment on each level, each with a total floor area of 57 m2. Two geothermal heat pumps, each with a cooling capacity of 2.58 kW and a heating capacity of 2.90 kW, connected to two vertical-borehole heat exchangers, were deployed for each apartment to maintain temperatures at 22 °C in winter and 26 °C in summer. The findings indicate that the estimated annual energy loads for cooling and heating for the apartment block are 42,758 kWh and 113 kWh, respectively. The corresponding electrical energy consumption amounted to 9294 kWh for space cooling and 113 kWh for space heating. The observed peak cooling load was approximately 9300 kJ/h (2.58 kW) per apartment, resulting in a power density of 45 W/m2. Moreover, the HP system achieved a 22% reduction in annual electric energy consumption compared to conventional air conditioning systems. This reduction in electric energy usage led to an annual CO2 reduction of 6.6 kg/m2.

Appraising the Feasibility of 3D Printing Construction in New Zealand Housing

The construction industry in New Zealand is significantly impacted by the importance of housing, particularly as urbanisation continues to grow in major cities. Modern construction methods, such as offsite construction and building automation, evolving into digital manufacturing and construction in the industry, have become prominent. Despite the global recognition of 3D printing technology, its adoption in the construction industry in New Zealand is still relatively limited. This study aims to examine the feasibility of 3D printing construction in response to current market challenges, innovation, and the 2050 net-zero carbon goal. Utilising Building Information Modelling (BIM) and Life Cycle Assessment (LCA) approaches, this study investigated the environmental impacts of three housing types: 3D printing (3DP), light steel framed (LSF), and timber. This study used cradle-to-cradle as the system boundary. The results indicate that the 3DP house emits 20% fewer carbon emissions than the traditional timber house and 25% less than the LSF house. Additionally, the 3DP house exhibits a 19% lower annual electric energy consumption than the timber house. Therefore, in response to the growing housing demand in New Zealand, the construction industry must innovate and embrace digital and advanced construction methods, including the adoption of 3D printing.

Modelling of Automated Store Energy Consumption

Over the last decade, a constantly growing trend of the popularization of self-service automated stores has been observed. Vending machines have been expanded into fully automated stores, the offer of which is comparable to small, conventional stores. One of the basic reasons for the popularization of modern automated stores is the reduction in a store’s energy consumption while ensuring a comparable range of products offered. The research into possibilities of reducing greenhouse gases emission is important in terms of the environment and climate protection. The research presented in the paper concerns the development of a model for determining electricity consumption, operating costs and CO2 emission of an automated store designed and developed by Delfin company. In the developed model, the potential location of the store, prevailing climatic conditions and expected product sales are taken into account. Estimated energy demand for the store is the information of key importance for the potential investors and the manufacturer of the automated store. It is worth emphasizing that the average annual electrical energy consumption evaluated for a grocery store of an area of 70 m2 amounted to approximately 38.4 MWh, while for an automated store of an area of 9 m2 and a comparable product range, the electricity consumption was approximately 10.1 MWh, i.e., 74% smaller.

Investigating energy saving and climate mitigation potentials in cement production – A case study in Ethiopia

The cement industry is one of the most energy and emission-intensive sectors, accounting for approximately 7% of total-industrial energy use and 7% of global CO2 emissions. This study investigates the potential energy savings and CO2 abatement in the cement plants of Ethiopia. A Benchmarking and Energy Saving Tool for Cement is used to compare the energy use performance of the individual cement plants to best practices. The study reveals that all the surveyed plants are less efficient, with an average energy saving potential of 36% indicating a significant potential for energy efficiency improvement. Then, twenty-eight energy efficiency measures are identified and analyzed using a bottom-up energy conservation supply curve model. The results show that the cost-effective electrical energy and fuel-saving potentials of these measures are estimated to be 99 Gigawatt hours per year which is about 11.5% of the plants’ annual electrical energy consumption and, 2.7 Petajoules per year which is to be 12.5% of the plants’ annual fuel consumption, respectively. The cost-effective fuel measures have an annual average CO2 emission reduction potential of 254 kilo-tonnes per year which covers about 5% of the total CO2 emission. Sensitivity analysis is conducted using the key parameters that show some discrepancy in the base case results. This study could be used as a reference for policymakers to understand the potential for energy savings and CO2 abatement. It could also be used to design policies in improving energy efficiency in the cement sector.

Power system static and dynamic security studies for the 1st phase of Crete Island Interconnection

The island of Crete is currently served by an autonomous electrical system being fed by oil-fired (Heavy fuel or light Diesel oil) thermal power plants and renewables (wind and PVs). The peak load and annual electric energy consumption are approximately 600 MW and 3 TWh respectively; wind and photovoltaic parks contribute approximately 20% of the electricity needs of the island. Due to the expensive fuel used, the Cretan power system has very high electric energy generation cost compared to the Greek mainland. On the other side the limited size of the system poses severe limitations to the penetration of renewable energy sources, not allowing to further exploit the high wind and solar potential of the island. According to the Ten Year Network Development Plan (TYNDP) of the Greek TSO (Independent Power Transmission Operator S.A. IPTO S.A.), the interconnection of Crete to the mainland Transmission System of Greece will be realized through two links: A 150 kV HVAC link between the Peloponnese and the Crete (Phase I) and a HVDC link connecting the metropolitan area of Athens with Crete (Phase II). The total length of submarine and underground cable of the HVAC link will be approximately 174km; it is at the limits of the AC technology and the longest and deepest worldwide at 150 kV level. A number of studies have been conducted by a joint group of IPTO and Hellenic Electricity Distribution Network Operator (HEDNO) for the design of this interconnection. This paper presents briefly the power system static and dynamic studies conducted for the design of the AC link and its operation. Firstly, the paper presents the main results of the static security study regarding the calculation of the maximum power transfer capability of the link and the selection of the reactive power compensation scheme of the cable. Results from dynamic security analysis studies are also presented. The small-signal stability analysis concludes that a new (intra-area) electromechanical oscillation is introduced to the National System after the interconnection. The damping of the electromechanical oscillations is sufficient; however the operation of power system stabilizers at power plants located both at the mainland and at Crete power system can increase significantly the damping of important oscillation modes. Finally with respect to the risk of loss of synchronism after a significant disturbance in the system of Crete, such as a three-phase fault (“transient stability”)- enough safety margin is estimated by means of Critical Clearing Time calculations.

Assessing the electricity energy efficiency of university campus exterior lighting system and proposing energy-saving strategies for carbon emission reduction.

This paper presents efficiencies research and energy-saving strategies for carbon emission reduction of the exterior lighting system of Avşar Campus of Kahramanmaraş Sütçü İmam University, Turkey. Once the campus’s average energy consumption for the previous five years was calculated, it was found to be 18,802 Megawatt hour/year (MWh/year), with 6,203 carbon dioxide (CO2) tons/year emissions. Also, the annual electrical energy consumption for exterior lighting was calculated as 670,395 MWh/year, with annual emissions of 221,170 CO2 tons/year. Inefficient lamp choices in exterior lighting systems and longer than necessary operating times have been identified as the causes of these high values. That’s because High-Pressure Sodium (HPS) lamps with an installed power of 109,050 Kilowatt (kW), which have a low efficiency but a high energy consumption, provide for 70% of exterior lighting. Thus, seven unique energy-saving strategies have been designed with the aim of decreasing total energy consumption and achieving more cost savings as well as less harmful emissions released into the atmosphere. All of the strategies were designed under the following three headings: dimming method, optimization of lamps’ operation times, and retrofitting lamps with new and technological ones. The study’s novelty lies in the creation of seven unique energy-saving strategies for the first time in light of the three headings highlighted, as well as their adjustment to a sophisticated campus with such high energy consumption. Once all of the proposed strategies are compared to the current system, it has been discovered that strategy-7 saves 81.656% energy consumption (547,418 MWh/year), 180,599 CO2 tons/year saving, and € 49,268 (€/year) cost-saving. Such a low energy consumption is vital for a rapidly growing and expanding campus in terms of carbon emissions, cost savings, and environmental quality.

Solar PV Penetration Scenarios for a University Campus in KSA

The Kingdom of Saudi Arabia (KSA) is committed to transition its fossil fuel-driven electricity generation to that from renewable energy technologies, such as solar photovoltaic (PV) and wind. The need to reduce greenhouse gas emissions has led it to announce an ambitious target of 40 GW of PV power capacity by 2030. The deployment of such a capacity needs to be augmented with analyses to overcome the challenges faced in terms of the technical capability of the country. This work contributes to this goal by investigating the utilisation of solar photovoltaic PV systems to supply medium-size entities such as universities with clean power, displacing the current fossil fuel power supply. Currently, such considerations are not fully addressed in KSA. The study used the University of Jeddah campus electrical load profile, taking into account future power needs. The methodology encompassed modelling the installation of multi-MW PV systems for the university by considering weather conditions, actual university consumption, load segregation, and economics under different development scenarios informed by surveys with decision makers at the university. The results showed that air conditioning loads alone were responsible for 79% of the campus electrical load and that a 4.5 MW PV system is able to supply half of the total campus annual electrical energy consumption of the year of 2019. The optimum scenario showed that utilising grid-connected PVs would decrease the total cost of electricity over the next two decades by 28 to 35 percent and would result in halving the current campus carbon emissions. The analysis concludes that the business-as-usual case is no longer the cheapest option for the campus.

Energy and reliability analysis of wastewater treatment plants in small communities in Ontario.

This paper presents energy and reliability analyses of eight wastewater treatment plants (WWTPs) operating in small communities in Ontario, Canada, with rated capacities ranging from 60 to 4,400 m3/d. Five different treatment technologies were investigated, namely, rotating biological contactor (RBC), sequencing batch reactor (SBR), membrane bioreactor (MBR), lagoon, and extended aeration activated sludge process (EAAS). Energy benchmarking based on key performance indicators (KPIs) was used to quantify the specific consumption of energy in WWTPs per unit of the pollutant removed. The overall annual electrical energy consumption was correlated to the volume of treated wastewater, the population equivalent, and the amounts of TSS and BOD removed. The RBC plants showed a distinctive advantage for all energy KPIs assessed, while SBR plants yielded the highest values of energy KPIs. Analyses of the expected percentage of compliance with discharge standards and the coefficient of reliability (COR) based on the WWTPs' performance records showed that few WWTPs were able to achieve reliability levels over 95%, considering the mandated discharge standards under the current operating and maintenance conditions. Within each technology, the treatment train, operating conditions, maintenance level, and age of infrastructure were important elements that contributed to the large variability observed.

분산형 모듈러 데이터센터를 위한 태양광 발전시스템 경제성평가

Among the measures to apply renewable energy to data centers, solar power generation is considered to be the most applicable and renewable energy currently available because of the physical conditions in which container-type distributed data centers are installed outdoors and data centers are operated 24 hours a day. Therefore, when the telephotovoltaic system was applied to distributed data centers based on domestic weather data, energy simulation was conducted, and the applicability of the system was evaluated through economic evaluation. As a result of the analysis, the average monthly predicted consumption was 8151 kWh, 9021 kWh, 9388 kWh, and 9712 kWh, respectively, in the four regions, and the overall average monthly energy consumption was calculated as 9068 kWh. The average power generation was 518 kWh, 616 kWh, 624 kWh, and 512 kWh, respectively, in four regions, and the average ratio of solar power generation supply based on annual electric energy consumption was 6.3%. When applying the solar power generation system to the distributed data center, average annual energy saving was calculated as KRW 1,429,890, and the initial investment recovery period was evaluated as an average of 6.45 years.

Energy Consumption Indicators for Public Lighting

Public outdoor (road) lighting consumes about 1.5 % of total electrical energy consumption [1]. Therefore, if the energy consumption for public lighting can be reduced by 30 % to 50 %, great energy savings can be achieved. With the use of LEDs and modern lighting technology, this is already possible. But to distinguish good sustainable lighting from poor and unsustainable lighting that needs to be refurbished faster, we first need reliable sustainability or energy consumption indicators. This paper presents different sustainability and energy consumption indicators for public lighting and evaluates them, using data on public lighting installations from the 25 EU countries. As shown in the paper, different indicators can give completely different results, so they should be used with caution. The main problem is that not all the data needed is available. Therefore, in the future, other data should be collected in addition to the annual electrical energy consumption for public lighting.

Investigation of photovoltaic-hydrogen power system for a real house in Turkey: Hydrogen blending to natural gas effects on system design

In the study, the effects of hydrogen mixing studies at the rate of 20% to the natural gas system which is an ongoing study in Turkey, on the photovoltaic system (PV) is investigated using a real house consumption. Providing the annual electrical energy consumption (1936,83 kWh) and 20% of natural gas consumption (62,4 m3) of a real house with hydrogen is included in the study. A PV-hydrogen system is theoretically investigated to provide the energy required for hydrogen production from solar panels. Hydrogen blending effects on PV size, capacity usage, and carbon footprint are analyzed. Thus, the contribution was also made to the “green hydrogen” works and reduction of the carbon footprint of the house. It was found that the required hydrogen for electricity can be provided 52,5 m2 solar panel area and 14,28% increase in this area and installed power can provide an amount of hydrogen that need for 20% hydrogen blending to the natural gas system. The overall system capacity usage decreased when the system is used for 20% hydrogen blending to the natural gas system. The carbon footprint of the house was decreased by 67,5%. If the hydrogen has not been blended with 20% natural gas, this ratio would have been 59,2%.

An approach to select an energy-efficient shading device for the south-oriented façades in heritage buildings in Alexandria, Egypt

The different shading devices originally used in heritage buildings (if existed) might not be the optimal shading device to conserve the electrical energy consumed by the heating, ventilation, and air conditioning systems (HVAC). However, finding a suitable shading device that can improve thermal comfort without compromising the electrical energy consumption is considered a challenge since utilizing an inappropriate one could result in consuming more electrical energy than it should. This study aimed to propose an approach to selecting the best shading device between external and internal alternatives with controlling the HVAC system temperature setpoint to increase energy efficiency and achieve thermal comfort in south-oriented façades of heritage buildings in Alexandria in Egypt. The results showed that using the external horizontal blinds and microlouvre at certain HVAC temperature setpoints could save up to 46% and 35% of the HVAC annual electrical energy consumption and achieving thermal comfort on 228 and 261 days, respectively. Meanwhile, applying the optimal annual operating schedule approach achieved 365 thermally comfortable days, saving around 35% of the HVAC annual electrical energy consumption.

Investigating the Impact of Integration the Saudi Code of Energy Conservation with the Solar PV Systems in Residential Buildings

The demand for air conditioning is increasing day by day in the world’s hot and humid climate areas. Energy conservation in buildings can play a vital role in meeting this high cooling demand. This paper attempts to consider the impacts of energy efficiency and renewable energy measures on the energy demand of Saudi Arabia’s residential buildings. The energy analysis and economic feasibility analysis of thermal insulations are performed in this paper by investigating the effect of residential buildings’ thermal insulations on the economic feasibility of grid-connected photovoltaic systems. This was the combined effort of building owners and government, and buildings were examined if a photovoltaic system and thermal insulation were used. The study was conducted in the three climate zones in Saudi Arabia. The results showed that the building base case’s annual electrical energy consumption in Riyadh city was 67,095 kWh, Hail 57,373 kWh, and Abha 26,799 kWh. For the basic case-building in Riyadh, 69% of the total electrical energy was used for cooling and heating. Applying the Saudi Building Code requirement for Riyadh will provide only 18% of the total energy used for cooling and heating. RETScreen 6.1 software was used to design a photovoltaic system; the analysis was done using technical and economic indicators. The annual yield factor for Riyadh, Hail, and Abha was 1649 kWh/kWp/year, 1711 kWh/kWp/year, and 1765 kWh/kWp/year, respectively. The capacity factors for Riyadh, Hail, and Abha were 18.8%, 19.5%, and 20.1%, respectively. The Unified photovoltaic Levelized energy costs were 0.031, 0.030, and 0.029 $/kWh for Riyadh, Hail, and Abha, respectively. Finally, the Net Present Value and greenhouse gas emissions reduction have been estimated.

Thermal Performance Optimization for Residential Buildings in Basra City

The present study investigates many parameters in the design of a residential building consisted of 6 floors with a construction area 240m2 located in Basra city. This study aims to reduce electric energy consumption utilized for cooling and heating of the building. The parameters which studied included: the effect of building façade, the exterior color of the external walls, the glazing distribution and the shape of the building. eQuest energy simulation program is used to simulate the annual building energy consumption, the program uses the hourly annual collected weather data. The results show that orientation the building façade toward the north direction is the best in the design of the building. The saving in annual electric energy consumption is about 11%. Moreover, the external color of the building has a strong effect on building cooling and heating energy consumption. By utilizing white exterior wall color, the annual electric energy consumption reduced by about 12%. The results also showed that by utilizing proper glazing distribution the electric energy consumption could be reduced by 3%. When all enhancements were combined an optimum building case were found. For the optimum case, the annual electric energy consumption was reduced by 35% compared to the base building case.

Parametric modeling and simulation of Low temperature energy storage for cold-climate multi-family residences using a geothermal heat pump system with integrated phase change material storage tank

A novel geothermal heat pump (GHP) system with an integrated low- to moderate-temperature salt hydrate phase change material (PCM) storage tank for buildings in cold climates is proposed in this study. The purpose of the PCM storage tank is to dampen peak heating loads and to remove annual ground thermal load imbalances on the ground heat exchanger (GHX) to assist in achieving an optimally-sized GHX. As heat is extracted from the closed-loop system by heat pumps in heating mode, a significant portion of this heat is used to solidify a salt hydrate PCM. This heat of fusion is later released back into the heat transfer fluid, storing it in the PCM tank and GHX for later diurnal and seasonal use. To examine the merits of the proposed concept, electric utility meter data on 15-minute time intervals were mined from an actual apartment building and used to estimate space heating, cooling, and hot water heating loads. Those data were used in an hourly, dynamic 20-year life-cycle simulation model in TRNSYS to design an optimum combination of GHX and PCM storage, where each component was sized to balance the annual ground thermal loads. The system simulation results show significant potential for GHX size reduction with a PCM storage tank, but the system is quite sensitive to the PCM melt temperature due to significant hysteretic nature of the salt hydrate PCM heating and cooling curves. We also find that there is no unique optimum unless other factors are considered such as installation cost and physical constraints; many combinations of GHX size and PCM mass are capable of achieving the design goal with similar annual electric energy consumption. For the cases examined here, a PCM melt temperature of 27 °C yields the most favorable economic results, and a preliminary economic analysis suggests that with typical drilling cost and PCM tank cost values, the GHX size can be reduced by over 50 %.

Performance Analysis of a Grid-Connected Rooftop Solar Photovoltaic System

Turkey is among the countries largely dependent on energy import. This dependency has increased interest in new and alternative energy sources. Installation of rooftop solar photovoltaic systems (RSPSs) in Turkey is increasing continuously regarding geographical and meteorological conditions. This paper presents an insight into the potential situation for Turkey and a simulation study for the RSPS designing and calculation for the faculty building at Marmara University in Istanbul. This simulation study demonstrates that 84.75-kWp grid-connected RSPS can produce remarkable power. The system is performed in detail with the PV*SOL software (Premium 2017 R8 - Test Version, Valentin Software GmbH, Berlin, Germany). Detailed financial and performance analysis of the grid-connected RSPS for faculty building with various parameters is also carried out in this study. According to the simulation results, the system supplies 13.2% of the faculty buildings’ annual electrical energy consumption. The annual savings value of faculty buildings’ electrical consumption is approximately 90,298 kWh energy which costs roughly $7296. A photovoltaic (PV) system installation for the faculty building, which has considerable potential for solar energy and sunshine duration, is indispensable for clean energy requirements and was supported by the simulation results. This paper can be considered to be a basic feasibility study prior to moving on to the implementation project.

Biogas Production Potential from Animal Manure in Samsun Province of Turkey

Abstract The aim of this study was to determine biogas amount and the energy value produced from animal manure in Samsun province, Turkey. For this purpose, biogas potential was calculated considering the number of cattle, buffalo and laying hens in the province. Samsun has a total of about 300 thousand cattle, 18 thousand buffalo, and 1.4 million laying hens. From these animals in the province, 2.95 million t of cattle manure, 178 thousand t of buffalo manure, and 40 thousand t of laying hens manure, including the total of 3.2 Mt of manure per year is obtained. Annually, 53.6 Mm3 of biogas can be produced from the usable amount of this manure. The heating value of biogas produced from this manure is about 1.22 PJ. The electricity production from this biogas is about 135 GWhel. These values can provide 4.96% of Samsun’s annual electrical energy consumption (2720 GWhel). The distribution of these calculated amounts by districts was mapped. When districts are listed according to the biogas production amount, the top seven Samsun districts are Bafra (16.2%), Center (16.0%), Carsamba (12.1%), Vezirkopru (11.0%), Terme (7.6%), Alacam (7.4%) and Havza (7.0%).

Evaluation of mosques in terms of thermal comfort and energy consumption in a temperate-humid climate

Mosques are a type of religious building of where the frequency of use changes daily. Mosques are used at different hours and intervals. Therefore, they should be analyzed differently from residential and office buildings in terms of thermal comfort. Heating, cooling and air conditioning equipment are used in the mosques to provide thermal comfort. Generally, in order to provide thermal comfort, HVAC systems are used, which consume secondary energy sources. The aim of this study is to measure the indoor thermal comfort levels and their compliance with international standards in two mosques that have natural and mechanical ventilation systems, in addition to different heating-cooling systems. In order to monitor the electrical energy consumed during the process of maintaining the thermal comfort in the mosques, annual electrical energy consumption data were obtained via energy analyzers and electric bills. The thermal comfort values were compared to the international standards. By taking into account the results of the measurements and obtained energy data, design proposals for future mosques and recommendations for scheduling air conditioning systems according to building usage practices are presented.

Electrical and thermal energy in private hospitals: Consumption indicators focused on healthcare activity

Improving energy efficiency in healthcare buildings is a major challenge in this sector of engineering. However, the energy consumption indicator commonly used in public hospitals (kWh per bed) does not take into account the healthcare activity carried out in these buildings. An analysis of the annual thermal and electrical energy consumption was performed in 13 Spanish private hospitals between 2008 and 2017 intending to find energy consumption indicators based on the healthcare activity that takes place in a hospital. All the buildings under study had been either built or retrofitted between 1990 and 2013, with useful floor area and number of beds 2314-23,888 m2 and 20–264 beds. The results showed a high correlation between the average annual energy consumption and the number of annual discharges, number of emergencies actions and number of hospitalization stays. Similar statistical correlations were also observed between useful floor area and number of staff. However, a low correlation was detected between energy consumption and number of beds. Additionally, number of annual surgeries, laboratory tests, births, and endoscopies, were studied, proving that they are also directly related with the annual energy consumption per staff member. Finally, based on the healthcare activity, final energy consumption indicators are proposed.

Optimization of Performance Parameter Design and Energy Use Prediction for Nearly Zero Energy Buildings

Optimizing key parameters with energy consumption as the control target can minimize the heating and cooling needs of buildings. In this paper we focus on the optimization of performance parameters design and the prediction of energy consumption for nearly Zero Energy Buildings (nZEB). The optimal combination of various performance parameters and the Energy Saving Ratio (ESR)are studied by using a large volume of simulation data. Artificial neural networks (ANNs) are applied for the prediction of annual electrical energy consumption in a nearly Zero Energy Building designs located in Shenyang (China). The data of the energy demand for our test is obtained by using building simulation techniques. The results demonstrate that the heating energy demand for our test nearly Zero Energy Building is 17.42 KW·h/(m2·a). The Energy Saving Ratio of window-to-wall ratios optimization is the most obvious, followed by thermal performance parameters of the window, and finally the insulation thickness. The maximum relative error of building energy consumption prediction is 6.46% when using the artificial neural network model to predict energy consumption. The establishment of this prediction method enables architects to easily and accurately obtain the energy consumption of buildings during the design phase.