kWh Of Energy Research Articles

Temperature effect of biogas production from a greenhouse biogas digester

Globally, energy challenges are increasing with population growth. Many countries solely depend on fossil fuels (oil, coal, natural gas, etc.) for energy generation for different processes. Fossil fuels fall under non-renewable energy sources, are polluters of the environment, and get depleted faster, thus making it challenging to sustain a continuous energy supply. Therefore, there is a need for alternative sources of energy to mitigate the hazards associated with the utilization of fossil fuels. The present study aims to monitor the performance of a three-meter cubic (3 m3) greenhouse biogas digester, focusing on the temperature effect in biodegrading cow dung materials for gas generation. The study was conducted under mesophilic temperature conditions, pH, and hydraulic retention time for 30 days. Results revealed that slurry temperatures of about 33.5 ℃ and ambient temperatures of about 35 ℃ resulted in a remarkable peak biogas yield of 0.3 m3 on the 23rd day of the month. After the optimum yield of the biogas, the performance declined and was ascribed to the non-supply of the new feedstock, and the environment in the reactor became acidic, hence hindering the biodegradation process. Ultimately, the total biogas yield obtained from the study was 2.58 m3, equivalent to 15.48 kWh of energy. This amount of bio-generated energy was twofold the average daily electricity consumption of middle-income South African households. It was demonstrated that temperature was a major factor influencing the performance of the assembled biogas digesters and, thus, should be closely monitored for appreciable biogas production. This study is envisaged to pave the way for the future affordable and environmentally friendly biogas production process.

New hybrid system of PV/T, solar collectors, PEM electrolyzer, and HDH for hydrogen and freshwater production: Seasonal performance investigation

A new hybrid energy system of PV/T, flat plate collector, PEM electrolyzer, and humidification-dehumidification desalination is introduced here. A comprehensive mathematical model for the system seasonal performance is constructed and solved numerically using MATLAB software. A year-round comparison between the traditional PV/T performance and its concentrated counterpart indicates that the latter performs better compared to power, hydrogen, and freshwater production and system overall efficiency. The maximum monthly achieved PV/T efficiency, electrolyzer efficiency, desalination system Gain Output Ratio, and overall system efficiency are 52 %, 62 %, 4.8 %, and 44 %, respectively at a concentration ratio of 4 and maximum allowable PV temperature. The system produces 82,200 kWh of energy annually and provides 77,700 kWh and 1500 kWh to the electrolyzer and the electric heater, respectively. Moreover, the system produces an annual freshwater production of about 52,700 kg, out of which approximately 10,000 kg are consumed in the electrolysis process, and an annual hydrogen production of approximately 1120 kg.

Design and analysis of zero-energy and carbon buildings with renewable energy supply and recycled materials

Given the notable consumption of fossil fuels, buildings prioritize their energy utilization. This paper’s aim is to explore the primary strategies in attaining zero-energy and zero-carbon buildings. The investigation employs two specialized software programs: Design Builder, which analyzes energy usage, and PV Syst, which evaluates renewable energy requirements. The study is conducted in Fort Myers, USA, and Dubai, UAE, leveraging diverse regional and climate discrepancies, and real-world data on zero-energy and carbon constructions for comparison and validation. Within the Design Builder software, the research examines four strategies, with the first serving as the realistic baseline. By implementing the second strategy, utilizing internal shading devices such as Shade Roll, a reduction of 376 kWh in Fort Myers and 591 kWh in Dubai is achieved. The third strategy encompasses the deployment of blind-type internal shading systems, resulting in reductions of 212 kWh in Fort Myers and 348 kWh in Dubai. The fourth strategy involves integrating renewable energy via photovoltaic panels, injecting 323.5 kWh in Fort Myers and 2237 kWh in Dubai into the power grid for lighting purposes. Furthermore, 3200.5 kWh and 4722 kWh of energy are respectively injected into the grid for heating in Fort Myers and Dubai. Cooling, however, necessitates additional energy from the grid, amounting to 2243.94 kWh in Fort Myers and 9211.64 kWh in Dubai. In the pursuit of zero-carbon goals, the implementation of suitable low-carbon recycled materials, in place of primary building materials, reduces carbon dioxide emissions from 79 tons to 7.315 tons in Fort Myers and 7.038 tons in Dubai. By employing appropriate materials, the zero-carbon objective is attained.

PRINTING A «BRACKET» TYPE PART FOR AN ENERGY-EFFICIENT CAR

Additive technologies play an important role in modern automotive design and manufacturing, with their applications expanding every year. Originally used primarily for prototyping and mock-up production, 3D printing is now increasingly being used to manufacture key automotive components, with some companies offering fully 3D printed vehicles. This article analyzes the possibilities of printing load-bearing structures and the design of a key element - the electric motor mounting bracket for the TOQ car prototype. TOQ Prototype EV is an energy-efficient electric vehicle prototype being developed by the SU Racing Team from Satbayev University. The goal of the project is to create an ultra-light, durable, energy-efficient prototype vehicle with a long range of 1 kWh of energy. The use of new materials and additive technologies opens up the possibility of creating a variety of combinations, both for the production of parts with increased strength and for the use of advanced materials in the interior of the cabin. The process of prototyping an energy-efficient electric vehicle using additive manufacturing illustrates an innovative approach to improving energy efficiency and reducing energy consumption. This article details the process of designing an electric motor bracket using generative design and additive manufacturing. The study aims to evaluate the feasibility of 3D printing the load-bearing and critical elements of an electric vehicle prototype, as well as to simulate the loads when operating an electric motor with a peak power of 2 kW. Keywords: Mechanical engineering, automotive industry, additive manufacturing, 3D printing, industry 4.0, racing car, energy efficiency.

Energy efficiency of hydrogen production during dark fermentation

It is widely known that most of the world's energy is produced from non-renewable energy sources such as crude oil and coal. Hydrogen is an ideal fuel candidate with a high energy content and clean combustion product. Biohydrogen is an environmentally friendly, renewable biofuel with high energy density, making it a viable alternative to fossil fuels in the future. At the same time, despite the large number of articles on the intensification of both dark fermentation and anaerobic bioconversion in general, the operating costs of the proposed intensification methods are not well covered in the literature. The goal of the work was to estimate the conversion coefficient of thermal and electrical energy spent on the functioning of the process of dark fermentation of various organic wastes into the energy of produced hydrogen. A block diagram of the energy flows of the dark fermentation system and the structure of the energy consumption of the system were developed. The obtained literature and experimental data suggest that the conversion coefficient of energy into biohydrogen in the process of dark fermentation is less than 1, so to obtain 1 kWh of hydrogen it is necessary to expend more than 1 kWh of energy. At the same time, the use of a vortex layer apparatus for dark fermentation of the food waste model made it possible to increase the energy output of the process by more than 7 times, thereby bringing the values of the conversion coefficients of thermal and electrical energy closer to 1. Despite the fact that the energy efficiency of most known methods for producing hydrogen is higher than the energy efficiency of dark fermentation, it is worth noting that the raw material for producing hydrogen in the dark fermentation process is organic waste, and not high-energy fuel (natural gas, methane, coal) or water in the case of electrolysis. In addition, the use of a vortex layer apparatus for pre-treatment of the dark fermentation substrate made it possible to achieve electricity conversion coefficient values 40% higher than with water electrolysis.

Economic and strategic challenges in microgrid integration: Insights from operational dynamics and renewable energy potential

With the integration of a large number of microgrids in the power distribution network operation, economic and strategic challenges arise. To address these challenges, this research provides a comprehensive investigation into the operational, economic, and strategic dynamics of microgrids. Through careful data analysis, the study interprets the complications of microgrid responses to seasonal changes. It also investigates energy consumption patterns and production dynamics. The detailed analysis of microgrid configurations reveals the unique attributes and challenges of PV, wind, and hydropower microgrids. Moreover, the research explains the financial implications of microgrid integration, from setup costs to potential ROI. It is also examining the cooperative relationship between microgrids and conventional grids. Key findings highlight that solar microgrids contribute 3.2% to 5.3%, wind microgrids provide 5.9% to 7.4%, and hydropower microgrids contribute 24.4% of total power. Energy purchase peaks at 850,000 kWh in August and declines to 580,000 kWh in May. 170,000 kWh of energy is sold back to the grid in May. Moreover, the grid energy costs reduced from $0.178 kWh to $0.30 kWh. The total net present cost of the system is achieved at $37,880,023.33. Renewable energy production ranges from 480 kW to 2,300 kW, with a penetration level reaching 160%.

Environmental impacts of oil extraction in blocks 16 and 67 of the Yasuní Reserve in the Amazonian Forest: Combined qualitative and Life-Cycle Assessment

This research analyses 24 years of oil extraction in blocks 16 and 67 of the Yasuní National Park (YNP) in the Amazonian Forest of Ecuador, one of the most biodiverse spaces in the world and with the current presence of ancient indigenous communities. As a novel contribution, we have carried out a Life-Cycle Assessment (LCA) that quantifies the footprints associated with the extraction, transportation, refining, distribution and final uses of the oil in four different scenarios (oil for asphalt use, electricity, marine fuel and passenger car transport). This study also sheds light on the energy return at the point of use of different oil-derivatives, and complements this with a qualitative analysis of the social, cultural and environmental implications for the Waorani communities. We conclude that the environmental burdens of the extraction process in blocks 16 and 67 in 2015 were greater than those of countries such as the United States, Saudi Arabia and Indonesia, based on the analysis of 11 impact categories. The blocks' operation is the most unfavourable for the categories of Terrestrial Acidification Potential (TAP), Global Warming Potential (GWP), Terrestrial Ecotoxicity Potential (TEP) and Ecosystem Quality Loss Potential (EQL), with increments of 804.15 %, 105.36 %, 506.29 % and 210.73 %, respectively, in relation to the average of the rest of the extraction systems analysed. Specifically, the present case study shows 75.18 % higher impacts in the blocks addressed, when compared to the Ecuadorian average. During the period 1999-2022, the carbon emissions associated with the oil extraction in these blocks have increased by 139.01%. It has been detected a neo-colonial economic behaviour: while the Ecuadorian state received 21% of the sales, the Spanish government and the oil companies received, on average, 38% and 41% of the per-litre average fuel price, respectively. Thus, 79% of the income stayed in the Global North. We conclude that, on average, 19.64 % of the impacts associated with crude oil production and consumption occur in the Amazonian region of the YNP, depending on the fuel used and the consumption mechanism. For the Global Warming Potential (GWP) impact category, the extraction process carries, on average, 34.51 % of the weight in all of the life-cycle impacts, depending on the consumption scenario. It was also estimated that to be able to use 0.33 kWh of electricity from fuel combustion, 0.47 kWh of energy for goods transport and 0.20 kWh for passenger transport, an investment of 1 kWh is required, with an average extended EROI of 1:3.33. According to the qualitative analysis performed, it has been concluded that the main local impacts are related to the obstacles in environmental monitoring and information, the economic dependence of the communities on the oil extraction company, and cultural transformations; impacts that are not easily quantifiable or detectable using other methodologies. The combination of the qualitative analysis and LCA showed that the neo-colonial economic distribution did not compensate the social and environmental impacts of the oil extraction occurred in the YNP.

Comparative Energy and Economic Analysis of Dish Stirling Engine and National Grid Electricity for Residential Building in Mafraq, Jordan

The primary purpose of this research is to determine the most economical approach to installing a solar dish Stirling engine (SDSE) system on a building for residential purposes in Mafraq while taking into account the local weather, usual monthly consumption of energy and the prices charged by the local powered utility. The house uses an average of 622.25 kWh of energy every month, with the highest consumption in February and the lowest in May. A range of optical efficiencies between 50% and 98% are used to mount the SDSE system. This study evaluated the relationship between the price of electrical energy and the amount of power consumed to identify the times of day when energy consumption is highest. Another approach relevant to consider is solar power, which likewise varies across the whole year. When the available intensity of the sun and power rates are at their peak, an SDSE system is regarded as a feasible solution for fulfilling the energy requirements. This is because SDSE systems can still make electricity even during cloudy days. This work also includes a comprehensive analysis of the solar power that an SDSE receives and the generated electrical power.

Revolutionary Energy Harvesting: Gravity‐Driven Piezocatalysts for Sustainable Hydrogen Production in MoS2@Mo2CTx Systems

AbstractHydrogen (H2) is mainly produced using steam methane reforming, electrolysis, and gasification, which require external energy and special catalysts. A new catalyst by combining MoS2 nanoflowers (NFs) with metal carbide/nitride nanosheets (Mo2CTx MXene) to create a nanosheet bending moment. The MoS2@Mo2CTx heterostructures achieve a production rate of 1164.8 µmol g−1 h−1 under an application of mechanical force, 4.01 and 3.06 times higher than Mo2CTx and MoS2 alone, due to enhanced charge transfer from MoS2's piezoelectricity and Mo2CTx's conductivity. This study introduces a pioneering methodology that harnesses gravitational energy as a continuous mechanical force, simulated using a peristaltic pump, to drive the piezocatalytic hydrogen evolution reaction (HER), achieving a notable hydrogen production rate of 454.1 µmol g−1 over 24 hours and demonstrating a sustained capability for hydrogen generation. The theoretical calculation results validate the piezoelectric potential in water‐flow‐pressure triggered HER systems. The piezocatalytic HER system, assuming powered by the Hoover Dam, will produce 290.9 kmoles of hydrogen per ton daily, equivalent to utilizing 19 150 kWh of energy in the electrocatalytic system. The simulated gravity‐driven water flow using MoS2@Mo2CTx piezocatalysts for H2 generation demonstrates superior efficiency by eliminating common thermal energy conversion losses, marking a significant breakthrough in sustainable hydrogen production technologies.

Renewable energy sources in Kyrgyzstan and energy supply to rural consumers

The study assesses the potential of renewable energy sources in Kyrgyzstan and explores their application to provide energy to rural consumers. This study used an approximation of the parabolic function of solar radiation change, statistical processing of data on the average annual water flow of small rivers, as well as calculation of the volume of manure produced and its processing into biogas and bio fertilisers to assess their potential in agriculture and environmental impact. Kyrgyzstan, located between 40 and 68° north latitude, has evenly distributed solar radiation, small rivers and biomass, which have significant renewable resources. The distribution of solar radiation on the territory corresponds to the normal law of the monthly average mathematical expectation of 175.79 kWh/(m²*month) and a standard deviation of 92.44 kWh/(m²*month). On average, each square metre of a solar power plant can produce 0.451 kWh of energy. The intervals of average water discharge between the small rivers of Kyrgyzstan follow a power law distribution with a mathematical expectation of 3.112 m³/s and a standard deviation of 2.46 m³/s. With a natural water flow rate of 0.652 m³/s, a low-pressure micro-hydroelectric power plant (with a water head of 1 to 2 m) can generate up to 8.95 kW of power. The total consumption of biogas by an average farm in Kyrgyzstan and its consumption for heating raw materials in a bioreactor during the cold season ranges from 16.34 to 18.93 kg/hour. This demand for biogas is met by producing domestic feedstock (animal manure) using compact biogas plants with reactors of up to 20 m³. These facts indicate that the use of the above-mentioned renewable energy sources in Kyrgyzstan can provide autonomous power supply to remote rural consumers and contribute to solving existing environmental problems, as well as energy-saving

PERANCANGAN PEMBANGKIT LISTRIK TENAGA SURYA (PLTS) PADA ATAP GEDUNG PARKIR BANDAR UDARA INTERNASIONAL I GUSTI NGURAH RAI

Using sustainable energy as a source of electrical energy is a safe way to increase ecosystem energy. One of them is the utilization of photovoltaic directed energy by upgrading the PLTS on top of the structure as a mechanism for introducing photovoltaic modules. The study finalized the plan to install PLTS on the roof of the I Gusti Ngurah Rai Airport parking lot as a source of electrical energy to reduce PLN electricity bills. The I Gusti Ngurah Rai Airport Parking Roof Solar Power Plant uses a battery-free on gridsystem with 600 units of 555Wp monocrystalline solar-based modules and four 100kW inverter units. The solar power plant to be built on the car park of Terminal I Gusti Ngurah Rai will have a capacity of 333kWp and will produce 604.929kWh of energy annually. The required speculation cost is Rp 3.004.620.000 and payback period for 6 years.

Performance of salt‐bridge microbial fuel cell (SB‐MFC) with various microorganism cultures on the generation of electricity from tofu wastewater

A suitable wastewater treatment system is required due to the high organic compound content in tofu wastewater, which can harm the environment. Biological treatment methods are effective for treating tofu wastewater due to its characteristics. Microbial fuel cells (MFCs) represent one such biological treatment option, effectively removing organic contaminants while generating low‐power electricity through bioenergetic reactions. In MFCs, microorganisms are used as biocatalysts to degrade the organic compounds present in wastewater. This study aimed to assess the efficacy of Salt‐bridge microbial fuel cells (SB‐MFC) using various acclimatized microbe cultures for reducing organic compounds and generating energy from tofu wastewater. Tofu wastewater was sterilized prior to introduction into the reactor. Additional microbes, including the native microbe consortium from tofu wastewater, Escherichia coli, Saccharomycopsis fibuligera, and a mixed culture of E. coli and S. fibuligera, were then introduced as biocatalysts. Carbon electrodes were utilized as both the anode and cathode. The results indicate that the mixed culture of E. coli and S. fibuligera significantly reduced COD and BOD5 levels, with removal rates of 82.74% and 76.53%, respectively, after 48 h. Furthermore, the culture generated a voltage of 676 mV, a current of 2.53 mA, a power density of 428 mWatt/m2, and 4.789×10‐2 kWh of energy. This study contributes to the advancement of SB‐MFC by utilizing wastewater and a combination of bacteria and yeast as biocatalysts.

Performance evaluation on a novel split thermoelectric system driven by solar energy for electric vehicle seats

This paper proposed a novel split thermoelectric system coupled with a photovoltaic panel for electric vehicle seats. The system separates the hot and cold ends of the thermoelectric device over a long distance with the flexible intermediate conductor, which solves the problem of poor heat dissipation at the hot end resulted from the integration of traditional TEC with the vehicle seats and improves the cooling and heating performance. A three-dimensional heat transfer model was established by COMSOL software to study the temperature field and the comprehensive performance. The results demonstrate that the system can maintain the seat temperatures in 27–30 °C in summer and 18–25 °C in winter, and there exists an optimum input power to maximize the COP. In addition, the seat temperature can be reduced from 60 °C to 31 °C in just 20 min under maximum heating load. The system performance is closely linked to the structure of the middle conductors, heat dissipation, solar radiation intensity, and ambient temperature. In winter, the power consumption of the system is reduced by about 84 % compared to the positive temperature coefficient thermistor with the COP being increased by 5.17. The contribution of the photovoltaic panel based on the studied conditions can save about 215.26 kWh of energy per year, and increase the driving distance of electric vehicles by approximately 1435 km.

Complementarity for Wind Power in Turkey: A Correlation Analysis Using XGBoost

Generation from resources such as wind power and photovoltaics are highly variable and relatively unpredictable. This variability has its own cost such that when the wind and photovoltaics happen to be low due to weather conditions, some other energy source should substitute them to satisfy the demand via market forces. The question is, to which extent does the thermal leg or the reservoir storage hydropower plants fill or substitute the gap in such cases? This is examined in the literature as the complementarity between the variable renewables and alternative sources of energy. For the purpose of answering this question, using hourly data for the period between 2015 and 2020 from Turkey, generation from the thermal leg and generation from reservoir storage hydropower plants are predicted with XGBoost, a machine learning algorithm, for different price and generation levels of wind power. The results point to a positive correlation between wind and reservoir storage hydropower, which concludes as the absence of complementarity between wind power and reservoir storage hydropower for the Turkish case. We comment that the feed-in-tariff system which guaranteed a price in US dollar terms per KwH of energy from reservoir storage hydropower decreased the incentives for substitution of wind power, cancelling out the balancing function of the reservoir storage hydropower. On the other hand, for positive prices, the natural gas fueled plants seem to substitute %63-%116 of the loss in wind power and the rest of the thermal leg happens to substitute %43-%59 of the loss in wind power, according to our calculations. These results point to a complementarity (over-substitution in this case) between wind power and the thermal leg.

Turning Waste into Wealth: A Conceptual Design of Limonene Production Plant from Waste Rubber Tyre

Limonene production represents a compelling opportunity in the global market, given its competitive landscape dominated by a few key players who control nearly half of the industrial-grade limonene market. Due to the high polyisoprene content in vehicle tyres, along with the rising number of waste rubber tyres, the production of limonene by pyrolysis of tyres may represent a future trend to turn waste into wealth. Hence, a conceptual plant design was carried out to determine the feasibility of limonene production from waste rubber tyres in Malaysia. This feasibility study involved Aspen Plus simulation and illustrated the main processes using Process Flow Diagram (PFD), Piping and Instrumentation Diagram (P&ID), and comprehensive stream table integrating material and energy balances. The desired product, which is limonene, was produced by the gas-solid pyrolysis within a conical spouted bed reactor (CSBR) in an inert atmosphere of non-oxidizing, achieving limonene of 98% purity. Besides, process optimization via pinch analysis has been performed to recover 223.84 kWh of energy using heat integration, resulting in 62.06% of energy saving. From the economic analysis conducted, the total capital investment is RM12.9 million and the annual revenue is RM124.7 million with an annual limonene production of 543.1 tons. The financial analysis demonstrated a robust return on investment (ROI) of 303%, a simple payback period of 0.33 years and ta Net Present Value (NPV) of RM 432.2 million.

Estimated greenhouse gas emissions in the Mbalmayo thermal power plant between 2016-2020 using the genetic-Gaussian algorithm coupling.

The greenhouse gas (GHG) emissions inventories in our context result from the production of electricity from fuel oil at the Mbalmayo thermal power plant between 2016 and 2020. Our study area is located in the Central Cameroon region. The empirical method of the second level of industrialisation was applied to estimate GHG emissions and the application of the genetic algorithm-Gaussian (GA-Gaussian) coupling method was used to optimise the estimation of GHG emissions. Our work is of an experimental nature and aims to estimate the quantities of GHG produced by the Mbalmayo thermal power plant during its operation. The search for the best objective function using genetic algorithms is designed to bring us closer to the best concentration, and the Gaussian model is used to estimate the concentration level. The results obtained show that the average monthly emissions in kilograms (kg) of GHGs from the Mbalmayo thermal power plant are: 526 kg for carbon dioxide (CO2), 971.41 kg for methane (CH4) and 309.41 kg for nitrous oxide (N2O), for an average monthly production of 6058.12 kWh of energy. Evaluation of the stack height shows that increasing the stack height helps to reduce local GHG concentrations. According to the Cameroonian standards published in 2021, the limit concentrations of GHGs remain below 30 mg/m3 for CO2 and 200 μg/m3 for N2O, while for CH4 we reach the limit value of 60 μg/m3. These results will enable the authorities to take appropriate measures to reduce GHG concentrations.

Simulation and experimental study of grid-connected photovoltaic power plants in a hot desert climate with fixed and dual-axis tracking

ABSTRACT This paper presents a comprehensive investigation into the performance of grid-connected photovoltaic (PV) power plants situated in a hot desert climate. The study employs a combination of simulation models and experimental data to assess the impact of two tracking systems – fixed and dual-axis – on the overall efficiency and energy yield of the PV installations. Through detailed simulations, we analyze the dynamic behavior of the PV systems under varying solar irradiance and the atmospheric conditions typical of hot desert environments. The dual-axis tracking system is compared against the conventional fixed-mount system to evaluate its effectiveness in maximizing energy production and improving the overall efficiency of the PV power plants. Experimental data collected from an actual grid-connected PV facility in a hot desert region is incorporated to validate the simulation results and enhance the accuracy of the study. The observed performance metrics include energy output, system reliability, and the impact of environmental factors on long-term sustainability. In general, in all weather conditions, solar tracking provides better yields than a fixed solar module, generating about 32% and 12% more energy in sunny and overcast weather conditions, respectively. Under sunny weather, the two-axis sun tracking system and a fixed tilt angle produce 333.228 kWh and 247.56 kWh of energy, respectively. The energy yield generated on a partly cloudy day by a two-axis sun tracking system and a fixed tilt angle PV system is 281.496 kWh and 257.856 kWh, respectively. In addition, the highest electricity gain for two-axis solar trackers versus fixed PV plants was found to be 34.6%, and the lowest value was found to be 9.16%. The experimental analysis shows that the efficiency of the polycrystalline PV module is 12% and 14% on sunny days and cloudy days, respectively. The comparison between fixed and dual-axis tracking systems contributes to the optimization of PV installations, enabling more informed decisions for sustainable energy production in regions characterized by high temperatures and intense solar radiation. To support the expanding applications of grid-tied PV systems with a sun tracker in the same or comparable location and climate conditions (Saharan environment), these studies have the practical utility of advising and offering helpful feedback to engineers, system designers, contractors, and investors.

OPTIMASI EFISIENSI ENERGI PADA MOBIL LISTRIK EMPAT PENUMPANG MELALUI SISTEM REGENERATIVE BRAKE

OPTIMASI EFISIENSI ENERGI PADA MOBIL LISTRIK EMPAT PENUMPANG MELALUI SISTEM REGENERATIVE BRAKE

Technical Feasibility of a Hydrail Tram–Train in NA: Okanagan Valley Electric Regional Passenger Rail (OVER PR)

Booming population and tourism have increased congestion, collisions, climate-harming emissions, and transport inequities in The Okanagan Valley, Canada. Surveys suggest that over 30% of residents would shift from cars back to public transit and intercity tram–trains if regional service and connections were improved. Intercity streetcars (aka light-rail tram–trains) have not run in Canada since their replacement in the 1950′s by the national highway system. UBC researchers analyzed a tram–train service fashioned after the current Karlsruhe model but powered by zero-emission hydrogen fuel cell/battery hybrid rail power (hydrail) technology, along a 342 km route between Osoyoos, B.C. at the US Border and Kamloops, B.C., the Canadian VIA rail hub. Hydrail trains have operated successfully since 2018 in Germany and were demonstrated in Quebec, Canada in 2023. However, hydrail combined with tram–train technology has never been tried in Canada. Single-train simulations (STSs) confirmed its technical feasibility, showing a roughly 8 h roundtrip travel time, at an average train velocity of 86 km/h. Each hydrail tram–train consumed 2400 kWh of energy, translating to 144 kg of hydrogen fuel per roundtrip. In total, five tons of H2/day would be consumed over 16 h daily by the 16-tram–train-vehicle fleet. The results provide valuable insights into technical aspects and energy requirements, serving as a foundation for future studies and decision-making processes in developing zero-emission passenger tram–train services not just for Okanagan Valley communities but all of Canada and NA.

Stacked ensemble learning approach for PCM-based double-pipe latent heat thermal energy storage prediction towards flexible building energy

Dynamic performance prediction of the PCM-based double-pipe latent heat thermal energy storage (LHTES) system plays an important role for building peak load shifting. This study presents a stacked ensemble learning framework for the phase change performance prediction of LHTES systems. The proposed model has a two-layer structure involving base and meta models: Regression Tree, Support Vector Regression and Linear Regression. Sensitivity analysis has been utilized for the feature extraction considering possible geometrical and physical parameters of LHTES systems with a fixed PCM volume that can store 0.94 kWh of energy within 255 min. Case studies show that the proposed model outperforms the base models in terms of both prediction accuracy and robustness. Compared with base models, the proposed model has a maximum 7.82% (charging) enhancement in Mean Absolute Percentage Error (MAPE) over all-range data sets and a maximum 16.43% enhancement in MAPE for the initial discharging stage, and has more stable predictive results within the high accuracy zone (accuracy > 95%) with a maximum 7.3% (charging) increase in the distribution density over all-range data sets and a maximum interquartile range reduction of 25.6% (middle discharging stage) in Mean Absolute Error. Application of the proposed model achieved more building peak load reduction.