Increasing Energy Costs Research Articles

247 Evaluating the use of soybean hulls on growth performance, carcass composition, and digestibility when fed to grow-finish pigs

Abstract The addition of fiber to grow-finish diets is commonly utilized in swine production formulation as energy costs increase. The objective of this study was to determine the effects of feeding soybean hulls (SBH) at increasing levels to grow-finish pigs on growth performance, carcass characteristics, and apparent total tract digestibility (ATTD) of nutrients. Utilizing 192 grower pigs [PIC 337×1050, initial body weight (BW) = 21.99 ± 2.75 kg] that were randomly assigned to split sexed pens (n = 12 pens/treatment), pens were assigned to one of four dietary treatments and fed over three feeding phases for the estimated BW ranges of 22 to 50 kg, 50 to 86 kg, and 86 to 127 kg. Diets were formulated to represent conventional corn and soybean meal diets, containing increasing levels of SBH at: 1) 0% SBH (0%); 2) 7.5% SBH (7.5%); 3) 15% SBH (15%); and 4) 22.5% SBH (22.5%). Within phase, diets had equal SID Lys:ME and energy was allowed to float. Individual BW and pen feed disappearance were collected for each phase to calculate pen average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency gain to feed ratio (G:F). On d 56 of study and during phase 2, 32 gilts (n = 8) were placed into individual metabolism crates, where total urine and feces were collected for 72 h to measure ATTD of gross energy (GE), nitrogen (N), neutral detergent fiber (NDF), and acid detergent fiber (ADF), then returned to original pens. At the completion of study, carcass weight, backfat depth, and loin depth were collected. Data were analyzed with the fixed effects of dietary treatment by ANOVA, linear, and quadratic contrasts. Pen served as the experimental unit for performance and carcass characteristics and pig as the experimental unit for ATTD analyses. Overall, as SBH increased from 0% to 22.5%, ADG tended to decrease (linear P = 0.060) with no difference in ADFI (P > 0.05), resulting in an overall decrease in G:F (0.38, 0.37, 0.36, 0.35; linear P < 0.001; 0, 7.5, 15 and 22.5% SBH, respectively). Final BW tended to decrease (linear P = 0.069) and carcass weight decreased (102.9, 102.7, 99.7, and 96.5 kg, linear P < 0.001) as SBH increased in diet. Carcass fat depth (P = 0.014) and loin depth (P = 0.006) linearly decreased with increasing levels of SBH in the diet. Increasing levels of SBH from 0% to 22.5% decreased ATTD of GE and N (linear P < 0.001) and tended to increase ATTD NDF and ADF (linear P = 0.056 and P = 0.073, respectively). Altogether, these data suggest increasing dietary SBH in grow-finish pig diets decreases growth efficiency and the digestibility of GE and N. Further, feeding high inclusion rates of SBH negatively impacts carcass yield, backfat and loin depth.

CARDIOVASCULAR RESPONSE AND COST OF DOWNHILL WALKING: A NOVEL EXERCISE MODALITY FOR PEOPLE WITH TYPE 2 DIABETES MELLITUS (T2DM)

INTRODUCTION & AIMS Exercise is a cornerstone in managing T2DM, along with diet and medication. Walking is the easiest to perform and most widely recommended exercise for people with T2DM. However, people with T2DM appear to walk 1200 to 2500 less steps per day than healthy people as many find exercise or walking to be exhausting. Downhill walking may be an alternative to conventional exercise for people with T2DM. Little is known about the metabolic cost of incline walking in people with T2DM. This study determined the energy cost of walking downhill, uphill, and on a flat level surface in people with T2DM. METHODS Participants walked on a treadmill at 2.5 km/hr, starting at 0% grade for 4 minutes and progressing to 4%, 8%, 12%, and 16% for four minutes at each grade. After resting for 10 minutes, they walked downhill at -4%, -8%, -12%, and -16% grades. Borg’s 6-20 RPE scale measured perceived exertion, while VO2, pulmonary ventilation, and energy expenditure were measured using an automated gas analysis system. Expired gas was collected every 15 seconds, and the average of the four readings of the fourth minute of walking at each grade was used for analysis. RESULTS Compared to flat-level the 4%, 8%, 12% and 16% incline increased energy cost by 17.5%, 42.6%, 68.3% and 95.1% respectively. Compared to level walking, walking at -4%, -8%, -12% and -16% treadmill decline decreased the metabolic energy cost by 13.1%, 15.2%, 17.9% and 13.4% respectively. Similarly, cardiometabolic response (HR) and perceived effort during downhill walking were lower than walking uphill. CONCLUSION Health professionals wanting to promote exercise as part of a lifestyle approach to manage T2DM could consider downhill walking as an exercise option as it induces lower cardiovascular and metabolic responses and is perceived as easier than uphill walking.

ECONOMIC FEASIBILITY OF ON-GRID PHOTOVOLTAIC SYSTEMS IN A SINGLE-FAMILY HOUSE IN RIO DE JANEIRO CITY

Brazil is a tropical country with favorable conditions for the generation and utilization of solar energy. This energy source becomes even more attractive when considering the dry periods that impact hydroelectric power generation in the country, resulting in an increase in energy costs reflected monthly in consumers' bills through tariff flags. In order to enhance residential architectural designs and promote energy efficiency, a feasibility study of photovoltaic systems was conducted, considering key economic indicators and the current tariff flags. To accomplish this, research was conducted in collaboration with Mounting Companies for a case study located in the city of Rio de Janeiro, adopting technical assumptions commonly used for residential photovoltaic system sizing. For the graphical sizing of the case study, factors such as the environment and summer and winter solstices were taken into account, and a shadow study was conducted to assess the potential loss of power generation by the photovoltaic system throughout the year. The shadow study revealed that, during both solstices, the optimal time for power generation by photovoltaic systems is between 9 a.m. and 6 p.m. Essentially, the calculated values of NPV (Net Present Value) and IRR (Internal Rate of Return) indicate that the project is economically viable and particularly advantageous during the yellow and red tariff flags, situations in which energy costs tend to be higher for consumers.

Carbon pricing and inflation expectations: Evidence from France

We study how firms’ price expectations and decisions are affected by carbon pricing, using a survey of French manufacturing firms. Exogenous variations in the price of carbon are obtained by high-frequency identification. A change in carbon price increases firms’ inflation expectations as well as their own expected and realized price growth. Initially, positive forecast errors emerge, but over time, the impact on price expectations proves to be more enduring than on actual price growth, leading to negative forecast errors in the medium- to long-run. Furthermore, our analysis reveals that firms’ responses to these carbon pricing shocks exhibit considerable heterogeneity. Low energy-intensive firms are worse at forecasting the effects of the shock on the evolution of their own prices and firms with narrower profit margins are less able to pass through the increase in energy costs to the prices of their final products. These findings align with models of information rigidities, shedding new light on how firms navigate and adapt to carbon pricing policies.

Residual energy use and energy efficiency improvement of European supermarket facilities during the post-COVID and energy crisis period

Supermarkets are significant consumers of electricity and contribute to the generation of associated pollutant emissions. This will help to mitigate the impact of increased energy costs on the prices of products sold in supermarkets. Therefore, it is essential to reduce energy consumption, starting with the equipment that consumes the most electricity, such as refrigeration, and using the residual thermal energy generated in supermarkets. This paper discusses the impact of rising energy costs in the post-Covid era and during the energy crisis. It evaluates the environmental and energy benefits of implementing energy improvements and utilizing residual energy in real supermarkets. The analysis takes into account the socio-economic characteristics of the EU-27 countries, which affect the economic feasibility of these measures. This would prevent the release of 122 tons of CO2 per year for each supermarket, resulting in energy savings of around 70 % or 305 kWh/m2. The required investments would have a payback period of 4 years.

Decarbonizing Process Heat Supply in the Austrian Pharmaceutical Industry

In the pharmaceutical industry, energy efficiency has played a minor role compared to other energy-intensive industries. However, there is a growing recognition of the need to address environmental concerns. With ambitious climate targets and the increasing demand for significant reductions in CO2 emissions, the pharmaceutical industry is now embracing the opportunity to enhance its sustainability practices. Mainly fossil fuels are used to provide process steam at moderate temperature levels at about 160-180°C and to a lesser extent to provide hot water or for on-site power production in CHPs. In this paper, the main processes with demands for process heat, such as media supply, cleaning, or air conditioning, are presented and possibilities for increasing efficiency, for switching to alternative heat supply and for using alternative process technologies are evaluated with respect to economics, but also regarding hurdles for implementation such as requirements for revalidation of production processes and possible necessity of re-approval of products. The present study highlights the potentials for decarbonization of the Austrian pharmaceutical industry using a generic but representative production site applying various measures that either reduce heating and cooling requirements or alter the temperature requirements for heat supply. It is shown that, at least for the example case, full decarbonization is technically feasibly without an increase in energy costs if efficiency measures are progressively used on demand level.

How photovoltaics make energy refurbishment more affordable in apartment buildings

The costs of energy efficiency renovation of Germany’s postwar apartment buildings have sharply increased since pre-covid years, as have interest rates and hence the costs of servicing loans that finance these renovations. Despite increases in energy costs, it has become virtually impossible to recoup energy-efficiency renovation costs through energy cost savings, with many projects bringing substantial losses. The common method of third parties offering rotating finance to ease the initial costs, and being repaid after short payback periods, therefore no longer works. On the other hand, rooftop photovoltaics have decreased sharply in price, and continue to do so. This study explores the economics of installing photovoltaics, with or without heat pumps, along with energy-efficiency renovation, based on two typical case study apartment buildings in North Rhine-Westphalia. Using fine-grained energy flow modelling and net-present value cost-benefit analysis, it finds that energy-efficiency renovation brings losses of over 80% but that these can be substantially reduced by the gains from rooftop PV, especially when a heat pump is included. The larger the PV system, the larger the gains, but roof size limits this. The study recommends that shared rooftop PV systems be promoted as the norm with comprehensive energy-efficiency renovation in Germany.

Optimization Techniques and Evaluation for Building an Integrated Lightweight Platform for AI and Data Collection Systems on Low-Power Edge Devices

Amidst an energy crisis stemming from increased energy costs and the looming threat of war, there has been a burgeoning interest in energy conservation and management worldwide. Industrial complexes constitute a significant portion of total energy consumption. Hence, reducing energy consumption in these complexes is imperative for energy preservation. Typically, factories within similar industries aggregate in industrial complexes and share similar energy utilities. However, they often fail to capitalize on this shared infrastructure efficiently. To address this issue, a network system employing a virtual utility plant has been proposed. This system enables proactive measures to counteract energy surplus or deficit through AI-based predictions, thereby maximizing energy efficiency. Nevertheless, deploying conventional server systems within factories poses considerable challenges. Therefore, leveraging edge devices, characterized by low power consumption, high efficiency, and minimal space requirements, proves highly advantageous. Consequently, this study focuses on constructing and employing data collection and AI systems to utilize edge devices as standalone systems in each factory. To optimize the AI system for low-performance edge devices, we employed the integration-learning AI modeling technique. Evaluation results demonstrate that the proposed system exhibits high stability and reliability.

Evaluation and Automation of Energy Consumption: A Tool for National Development

In developing countries like Nigeria, high energy inefficiency and poor technology have led to increased energy costs and wastage. This paper focuses on the second goal of the African Union Agenda 2063, which emphasizes the importance of science, technology, and innovation in creating well-educated citizens and a skills revolution. The objective is to investigate how evaluating and automating energy consumption can contribute to national development. The study utilizes a mixed-methods approach, gathering qualitative and quantitative data. The quantitative phase includes data collection from surveys via wellstructured questionnaires to quantify energy usage patterns and assess the potential for automation. The qualitative phase includes in-depth interviews with energy users on their perspectives on energy evaluation and automation. For data analysis, ETAP, SPSS, and Microsoft Excel version 2016 are utilized. Consequently, hardware and software applications are developed to automate energy consumption through the utilization of a microcontroller and a mobile app. The key findings reveal eight loads measured over a year that an automated meter consumed 806.65 Joules of energy, whereas the existing meter consumed 1447.23 Joules. This demonstrates that automated systems consume less energy compared to the existing meters. The study emphasizes the significance of efficient energy consumption for achieving sustainable development goals and explores the potential of automation in optimizing energy usage.

Assessment of Implementing Green Logistics Principles in Railway Transport: The Case of Lithuania

Today, green transport is a growing trend in terms of transport costs, CO2 emissions and satisfaction with logistics services. Green logistics is an environmentally friendly and sustainable logistics system that encompasses activities affecting logistics functions and processes, promoting the environment and the development of a circular economy. Rail transport is considered to be one of the least polluting modes of transport, but the fact that only electrified rail represents the concept of green logistics has been underemphasised, as the fleet consisting of diesel trains is a major challenge. This article aims to investigate the implementation of green logistics in railway transport in the case of Lithuania. The scientific literature, SWOT analysis, expert evaluation and parameter correlation methods were used to achieve this goal. An analysis of the internal and external factors of Lithuanian Railways in terms of green logistics has identified the main strengths of rail transport. These are environmental friendliness, electric trains reducing CO2 emissions, a strong focus on circular economy and others. The main weaknesses include the more extensive use of diesel trains, competition, etc. The external factors of the company show that the main opportunities are the reduction in net CO2 emissions to zero, the acquisition of more electric locomotives and others, while the main threats include an increase in energy costs or the complexity of implementing new technologies. An analysis of these factors has led to the construction of a SWOT matrix, which shows that the company’s strategy in the field of green logistics is quite strong, with more strengths than weaknesses. The results made it possible to identify the links between the individual implementation principles of green logistics in railway transport and provide strategic guidelines for the successful integration of green logistic principles into railway transport in Lithuania.

ИССЛЕДОВАНИЕ УСТОЙЧИВОСТИ ОПТИМАЛЬНЫХ ПАРАМЕТРОВ ПРИЦЕПНОГО ОПРЫСКИВАТЕЛЯ ПРИ ИЗМЕНЕНИИ УСЛОВИЙ РАБОТЫ

Research was carried out to identify changes in energy costs and the stability of the optimal parameters of a trailed sprayer when changing the numerical values of factors affecting its operation, to determine the possibility of stable operation in various conditions. The work was carried out using the example of a trailed sprayer for a 4K4a tractor, type MTZ-82, with an engine power of 80 hp. (optimal working width – 32 m, speed – 10 km/h, wheel diameter – 2 m, tank volume – 5000 l, wheel profile width – 0.2 m, sprayer weight distribution coefficient on its support wheels – 0.83) at changing the following operating conditions of the unit: cultivated field area from 1 to 101 hectares, paddock length from 0.1 to 1.1 km, soil density from 1.1 to 1.7 g/cm3, tanker productivity from 100 to 700 l/min , grain yield from 15 to 70 c/ha, seasonal volume of work per unit from 100 to 3600 ha, application rate of preparations from 50 to 330 l/ha, number of weeds per unit field area from 10 to 460 pcs/ m2. With an increase in the numerical values of the first four of the listed factors that determine the operating conditions of the sprayer, the total energy costs decreased by 200...2800 MJ/ha, an increase in the values of the indicators of the other four factors of the system led to an increase in the total energy costs by 300...5300 MJ/ha. At the same time, the optimal parameters of the sprayer remained unchanged regardless of the variation in the factors under consideration.

Technical solutions to reduce losses in magnetic cores and material consumption of three-phase transformer and reactor equipment

Purpose. The increase in energy costs and the need for further energy saving lead to an increase in requirements for reducing losses in the magnetic cores of transformers and reactors. Problem. The improvement of transformer and reactor equipment is traditionally carried out by applying the achievements of electrical materials science and new technologies to traditional designs and structures of electromagnetic systems. The basis of modern transformers is made up of laminated and twisted magnetic cores. The disadvantage of laminated magnetic cores is large additional losses in corner zones due to the texture of anisotropic steel. Disadvantage of twisted three-phase three-contour magnetic cores is large additional losses caused by the lack of magnetic coupling of three separate magnetic flux contours. The disadvantages of combined joint tape-plate magnetic cores are the unsatisfactory use of the active volume and increased losses, which are determined by the uneven distribution of the magnetic field and the negative impact of steel texture in the corner zones of the twisted parts. Aim. To determine the possibility of improving three-phase transformers and reactors. Methodology. The improvement is achieved by geometrical and structural transformations of the outer contours and elements of the varieties of magnetic cores. Results. The possibility of eliminating additional losses of a planar laminated magnetic core by a combination of anisotropic and isotropic steels at the appropriate location in the yoke-rod and corner sections is determined. With an octagonal outer contour of the combined magnetic core, a reduction in mass is achieved without an increase in losses. The mutually orthogonal position of the steel layers or the elements of the joint twisted and combined three-phase planar and spatial magnetic cores achieves magnetic coupling and elimination of additional losses of individual twisted contour sections. The hexagonal configurations of the inner contours of the twisted yoke-corner parts and the cross-sections of the laminated rods of the variants of the axial spatial joint magnetic core improve the magnetic flux density distribution and reduce the main losses of the yokes, as well as reduce the complexity of manufacturing rods from identical rectangular steel layers. Originality. The paper presents constructive and technological proposals and features of varieties of non-traditional planar and spatial, laminated, twisted and combined tape-plate joint magnetic cores, which differ in the combination of anisotropic, isotropic and amorphous steels, as well as the multifaceted geometric shape of contours and the spatial arrangement of elements. Based on the identity of the optimal geometric ratios of the variants of electromagnetic systems of transformers and reactors, with joint planar and spatial twisted and combined and tape-plate magnetic cores, the unification of the structure of transformer and reactor equipment with a capacity of I-III dimensions.

Abstract 121: Improvements in Cardiovascular Fitness Following Forced-Rate Aerobic Cycling in Individuals With Chronic Stroke

Introduction: Declines in cardiovascular function in individuals following stroke result in increased energy costs of movement, restrictions in participation, and increased risk for recurrent stroke and other cardiovascular diseases. We have developed a rehabilitation model that incorporates aerobic exercise training to harness its potential neuroplastic effects. Our aim is to identify the cardiovascular benefits from a forced-rate aerobic exercise (FE) intervention among individuals with chronic stroke compared to an upper extremity repetitive task practice (UE RTP) control group. Hypothesis: We hypothesized that FE would elicit greater improvements in cardiovascular fitness compared to the UE RTP intervention. Methods: A randomized clinical trial was conducted in which participants (N=60) completed 24 sessions over 8 weeks of FE followed by RTP (FE+RTP) or time-matched RTP alone. The FE+RTP group exercised at 60-80% of heart rate reserve on a motorized stationary semi-recumbent cycle ergometer for 45 minutes followed by 45 minutes of RTP. The control group completed 90 minutes of RTP. Metabolic exercise stress tests were conducted at baseline and post-intervention. Outcomes included peak oxygen consumption (peak VO2) and anaerobic threshold (AT). Results: Fifty participants completed the study intervention and pre/post stress tests. The FE+RTP group demonstrated significantly greater improvements in peak VO2 from 16.4±5.7 to 18.3±6.4 mL/min/kg compared to the RTP group (17.0±5.6 to 17.2±5.6 mL/min/kg, p=0.020) and significantly greater improvements in AT from 10.3±2.8 to 11.5±3.6 mL/min/kg compared to the RTP group (10.8±3.9 to 10.4±3.2 mL/min/kg, p=0.020). Conclusions: An aerobic exercise intervention integrated into rehabilitation was effective in eliciting significant and meaningful improvements in cardiovascular fitness. This novel rehabilitation model may be an effective approach to improve motor and cardiovascular function.

Integrated energy demand-supply modeling for low-carbon neighborhood planning

As the building stock is projected to double before the end of the half-century and the power grid is transitions to low-carbon resources, planning new construction hand in hand with the grid and its capacity is essential. This paper presents a method that combines urban building energy modeling and local planning of renewable energy sources (RES) using an optimization framework. The objective of this model is to minimize the investment and operational cost of meeting the energy needs of a group of buildings. The framework considers two urban-scale RES technologies, photovoltaic (PV) panels and small-scale wind turbines, alongside energy storage system (ESS) units that complement building demand in case of RES unavailability. The urban buildings are modeled abstractly as “shoeboxes” using the Urban Modeling Interface (umi) software. We tested the proposed framework on a real case study in a neighborhood in Chicago, Illinois, USA. The results include estimated building energy consumption, optimal capacity of the installed power supply resources, hourly operations, and corresponding energy costs for 2030. We also imposed different levels of CO2 emissions cuts. The results demonstrate that solar PV has the most prominent role in supplying local renewables to the neighborhood, with wind power making only a small contribution. Moreover, as we imposed different CO2 emissions caps, we found that ESS plays an increasingly important role at lower CO2 emissions levels. We can achieve a significant reduction in CO2 emissions with a limited increase in cost (75% emissions reduction at a 15% increase in overall energy costs). Overall, the results highlight the importance of modeling the interactions between building energy use and electricity system capacity expansion planning.

Solar-assisted poultry production in small-scale farms: a case study in the Bekaa semi-arid region, Lebanon

BackgroundIn Lebanon, poultry production is one of the major components of the agricultural sector; however, it suffers from increasing energy costs necessary to cover poultry heating requirements. This affects the profits of brooding farms, namely, small-scale farms in rural areas. Few studies have addressed the use of renewable energy in the poultry industry in Lebanon, with most having focused on modelling ventilation and air quality requirements in poultry houses. Therefore, there is a need to investigate the efficiency of renewable energy sources in providing heating requirements for poultry production. Accordingly, this study evaluates the performance of a solar-assisted, localized heating system in providing heat requirements for chicks in a renovated green poultry house in the Bekaa semi-arid rural region in Lebanon. For this aim, two brooding cycles were conducted during the warm and cold seasons in a greenhouse and were later replicated in a conventional poultry house.ResultsThe energy inputs in the green and conventional houses, respectively, were 33,995.39 and 40,656.97 MJ (1000 birds)−1 in the warm season, and 37,058.25 and 45,770.05 MJ (1000 birds)−1 in the cold season. Calculated energy efficiency values for the green and conventional poultry houses were, respectively, 0.58 and 0.50 in the warm season, and 0.46 and 0.41 in the cold season. The net return was negative for both systems and the benefit-to-cost ratio from broiler production was calculated to be 0.49 and 0.50 in the green and conventional houses, respectively. Life cycle cost analysis showed that adopting the green heating system in the studied farm would entail an 18.89% increase in cost over a period of 20 years as compared to the conventional system.ConclusionIt was concluded that poultry production is not profitable in small-scale farms in the studied area in Lebanon. The use of renewable energy might be more suited for large-scale broiler operations to achieve their purpose in reducing overall production costs. Optimization of the green system to fully satisfy the poultry energy requirements would render it more economically competitive.

Effects of long-term monocropping, rotation cropping, and fertilization on energy and fuel requirements for fall moldboard plowing in a clay-loam soil

With recent increases in energy costs, information on energy inputs is becoming a more important aspect in management decisions on selection of crop production systems. The effects of long-term (45–55 years) monocropping, rotation cropping, and fertilization on tillage energy (implement draft and tractor fuel consumption) were determined for a Brookston clay-loam soil in southwestern Ontario, Canada. Treatments included fertilized and unfertilized monocrop (continuous) corn (Zea mays L.), and a four year fertilized and unfertilized corn – oat (Avena sativa L.) – alfalfa (Medicago sativa L.) – alfalfa rotation with all phases of the rotation present in each year. The corn and second year alfalfa plots were moldboard plowed each fall after crop harvest, and then spring-tilled (disc, harrow) prior to planting; oat and first year alfalfa plots were not fall plowed or spring-tilled. Moldboard plow draft and tractor fuel consumption were measured annually from 2004 to 2014 using an instrumented tractor and the same plow and settings.Monocrop unfertilized corn consistently exhibited the greatest plow draft and tractor fuel consumption. Draft averaged over ten years was 13.0% higher for unfertilized than fertilized rotation corn, and 15.5% higher for fertilized than unfertilized second year alfalfa; fuel consumption was 10.4% higher for unfertilized than fertilized rotation corn and 5.1% higher for fertilized than unfertilized second year alfalfa. These differences were attributed to treatment-induced changes in soil strength. Both plow draft and fuel consumption were lower in rotation corn relative to monocrop corn, while plow draft was greater in fertilized alfalfa relative to unfertilized alfalfa due to greater root growth. This study demonstrated that long-term cropping systems can have substantial impacts on the energy required for tilling a clay loam soil.

Effects of dispatch algorithms and fuel variation on techno-economic performance of hybrid energy system in remote island

A stand-alone hybrid energy system is needed to mitigate the growing demand for future energy and to reduce emissions generated by conventional fuel sources. This work shows and proposes an optimum hybrid energy system configuration with less environmental pollution for a coastal region of Bangladesh with a load demand of 292.20 kWh/d and a peak load of 41.14 kW. This research presents the cost of energy (COE) and net present cost (NPC) for a PV-wind hybrid system with five alternative fuel generator technologies. For each possible configuration, the effects of three alternative dispatch algorithms, load following (LF), cycle charging (CC), and combined dispatch (CD), are examined. All three algorithms were validated using a genetic algorithm (GA), Cuckoo search algorithm (CUSA), Constrained Particle Swarm Optimization (CPSO), Harmony search algorithm (HSA), and Non-dominated Sorting Genetic Algorithm (NSGA-II). Furthermore, a sensitivity analysis is also conducted by utilizing the gasoline price, discount rate, battery cost, PV cost, and inflation rate. The results show that the PV-wind-natural gas-based system provides the minimum COE (0.196 USD/kWh) and NPC (270,483 USD) when the CD algorithm is followed. For the same optimal hybrid energy system, the COE is 0.201 USD/kWh, 0.0998 USD/kWh, 0.101 USD/kWh, 0.101 USD/kWh, and 0.0987 USD/kWh respectively for GA, CUSA, CPSO, HSA, and NSGA-II. However, COE increases by 8 % (0.212 USD/kWh) and 15 % (0.225 USD/kWh) when the CC and LF algorithms are followed. In addition, a comparison of all configurations reveals that the PV-wind-biomass configuration with the CD algorithm excludes biomass generators to lower the COE, making the system emission-free.

Model predictive control for demand flexibility of a residential building with multiple distributed energy resources

One of the major challenges with increasing penetration of renewable energy sources (e.g., solar and wind) is to maintain grid stability. Grid-interactive efficient buildings are regarded as a promising approach to advance the role buildings can play in energy system operations and planning. This paper evaluates the demand flexibility in a residential building located in Karlsruhe, Germany, incorporating multiple distributed energy resources, including a photovoltaic and battery system, an electric vehicle, an electric water heater and a heat pump. A multi-criteria optimization problem is formulated with model predictive control (MPC) for five cases of demand flexibility. The simulation results of five winter days show that the peak power during the peak periods can be reduced by 92%, 69%, 100%, and 100% for real-time pricing, demand limiting, load shedding, and load shifting, respectively. For the power tracking scenario, the MPC tracked the reference power profile successfully for 70% of the simulation time. Achieving demand flexibility does not necessarily cause an increase in energy costs.

NUMERICAL ANALYSIS OF WAVE ENERGY POINT ABSORBERS BUOY SHAPE

ABSTRACT: Energy demands have increased dramatically nowadays giving rise to the growing consumption of electricity, most of which is provided by fossil fuels, which has increased energy costs as well as the harmful emissions resulting from fuel combustion. This has resulted in advancements in the use of renewable energy sources to satisfy the current energy demands. These sources include the use of solar, wind, and wave power to generate energy in a green manner. This paper presents the use of wave energy point absorbers with various shapes to assess their performance when exposed to waves. Four buoy shapes are modelled and analyzed using Ansys Aqwa to observe their motion as well as their responsiveness to the out of balance forces subjected on them. The results show that the cylindrically shaped buoy can achieve around 52.8% more motion in the vertical direction when compared to the average motion of the different buoy designs. This shows that a cylinder buoy is the economic option for optimized wave energy absorption.

Assessment of the energy potential of agricultural residues in the Canary Islands: Promoting circular economy through bioenergy production

The Canary Islands, renowned for their tourism appeal, grapple with a pronounced energy challenge stemming from their geographic fragmentation and heavy reliance on external energy sources, particularly fossil fuels. Moreover, the region's history is marked by recurring energy crises, underscoring the imperative need for a swift and decisive transition towards renewable energy sources. This research examines the potential of waste biomass as a renewable energy source in the Canary Islands. This reliance on non-renewable energy sources leads to increased energy costs and greenhouse gas emissions, making the pursuit of a sustainable energy future a strategic priority in the region. This study proposes to assess the potential of residual biomass from the main crops of the Canary Islands, such as bananas, tomatoes, potatoes, and grapes, for bioenergy production. Statistical data were used to estimate the total availability of residues, while parameters like residue-to-product ratio, moisture content and calorific value were determined to calculate the energy potential of the residual biomass. The research findings reveal that the annual production of residual biomass from the primary crops in the Canary Islands is 234,744 tonnes (111,425 Tn/year from banana cultivation, 52,961 Tn/year from tomato cultivation, 40,102 Tn/year from potato cultivation, and 30,256 Tn/year from grape cultivation). This biomass has the potential to generate around 1.39 PJ of energy, equivalent to approximately 4.79% of the current energy consumption of the archipelago. Considering that renewable sources contribute to only around 20% of the energy production in the Canary Islands, the availability of this resource presents an exceptional opportunity for the region. By harnessing its natural resources, the Canary Islands can pursue sustainable economic growth while simultaneously mitigating negative environmental impacts. Definitely, the assessment of the potential of residual biomass plays a crucial role in evaluating sustainable energy resources and represents an important step towards a more sustainable energy future in the Canary Islands.