Actual Energy Cost Research Articles

Conventional Building Energy Performance and Actual Energy Costs: A Critical Reflection

Conventional Building Energy Performance and Actual Energy Costs: A Critical Reflection

Near-Optimal Time–Energy Tradeoffs for Deterministic Leader Election

We consider the energy complexity of the leader election problem in the single-hop radio network model, where each device v has a unique identifier ID ( v ) ∈{ 1, 2, ⋖ , N } . Energy is a scarce resource for small battery-powered devices. For such devices, most of the energy is often spent on communication, not on computation. To approximate the actual energy cost, the energy complexity of an algorithm is defined as the maximum over all devices of the number of time slots where the device transmits or listens. Much progress has been made in understanding the energy complexity of leader election in radio networks, but very little is known about the tradeoff between time and energy. Chang et al. [STOC 2017] showed that the optimal deterministic energy complexity of leader election is Θ (log log N ) if each device can simultaneously transmit and listen but still leaving the problem of determining the optimal time complexity under any given energy constraint. Time–energy tradeoff: For any k ≥ log log N , we show that a leader among at most n devices can be elected deterministically in O ( k ċ n 1+ε ) + O ( k ċ N 1/k ) time and O ( k ) energy if each device can simultaneously transmit and listen, where ε > 0 is any small constant. This improves upon the previous O ( N )-time O (log log N )-energy algorithm by Chang et al. [STOC 2017]. We provide lower bounds to show that the time–energy tradeoff of our algorithm is near-optimal. Dense instances: For the dense instances where the number of devices is n = Θ ( N ), we design a deterministic leader election algorithm using only O (1) energy. This improves upon the O (log* N )-energy algorithm by Jurdziński, Kutyłowski, and Zatopiański [PODC 2002] and the O (α ( N ))-energy algorithm by Chang et al. [STOC 2017]. More specifically, we show that the optimal deterministic energy complexity of leader election is \(\Theta (\max \lbrace 1, \log \tfrac{N}{n}\rbrace)\) if each device cannot simultaneously transmit and listen, and it is \(Θ (\max \lbrace 1, \log \log \tfrac{N}{n}\rbrace)\) if each device can simultaneously transmit and listen.

Methods for Evaluating Digital Financial Assets as the Basis for Future Trade Turnover

The author analyzes methods of cryptocurrency evaluation existing in foreign practice. Applicability of the comparative, income and cost approaches used in valuation activities, as well as possible methods within each of the approaches, is explored. It is determined that within the income approach, the discounted cash flow model and the exchange equation are applicable. The comparative approach involves the classic comparison of sales, while the cost approach contains two methods based on actual (energy cost method) and forecast (stock-flow ratio method) data.

Power load prediction of smart grid based on deep learning

Real electricity costs, weather, and historical load data are added as new reference data when analyzing the characteristics of the load change policy to improve the forecasting model. A load forecasting model for smart grid based on convolutional neural network(CNN) is proposed. The model first analyzes the characteristics of the variable model and determines the forecast model inputs using two methods of correlation analysis to understand the impact of actual energy costs, weather and other factors on the changes. Second, since Feedforward neural network is deficient in processing the correlation information between loads, the prediction model developed by the author was studied as CNN. After completing the training, input two sets of real datasets for final data analysis and comparison, and the results show that, LSTM, BP, SVR[UNK]MAPE[UNK]RMSE respectively 0.49%, 0.57%, 0.83%, 1.44% and 106.08 MW, 113.82MW, 169.77 MW, 285.61 MW. It can be seen that the prediction model proposed by the author has the highest accuracy and the best fit with the trend of actual load changes. It is proved that the CNN model has certain advantages when dealing with load forecasting problems related to time series.

Comparison of energy efficiency and costs related to conventional and LED road lighting installations

Comparison of conventional (usually high-pressure sodium (HPS)) and LED luminaires in street/road lighting is not often based on photometrically equivalent lighting solutions and/or correct economic analysis, which may lead to either overestimation or underestimation of savings of any kind. Therefore, this paper presents a correct methodology for the determination of actual energy efficiency and cost indicators in street/road lighting. Both neutral white (NW) and warm white (WW) LEDs, all relevant street/road lighting classes and pole layouts were considered. Analyzing optimal lighting solutions, characterized by the lowest installed power, it was shown that when considering mesopic effects the average energy savings achieved comparing LED (NW and WW) with HPS lighting solutions amounted to 41–62% and 29–59%, respectively, while the ratio between the total costs of the comparable LED (NW and WW) and HPS lighting solutions belonged to the ranges 0.59–1.26 and 0.61–1.14, respectively. An expanded sensitivity analysis of the costs, carried out considering not only the usually taken discount and electricity cost rates, but also the LED package lifetime, showed that the last only slightly influences the total costs. The effects of the use of more efficient LED packages expected in the near future were also analyzed.

Energy poverty signs in mountainous Greek areas: the case of Agrafa

ABSTRACT The paper studied the phenomenon of energy poverty in the Municipality of Agrafa, a mountainous region of Greece, aiming to enhance knowledge on the phenomenon within mountainous areas. For this purpose, a primary survey was undertaken, and various objective and subjective indicators were monitored. It was found that 62.4% of households in Agrafa are classified as energy poor according to the 10% index based on actual energy costs, while the percentage escalates to 91.3% based on required costs. Also, the compression of energy needs emerges as a significant side of the problem. The subjective indicators highlight supplementary behavioural aspects of the phenomenon. A set of statistical tests was applied, i.e. cluster analysis, Chi-square tests of independence and regression analysis, enriching the outcomes of the research. Finally, the directions of energy policy are evaluated, highlighting the need for targeted research and policy measures adapted to mountainous areas.

Market-Based Versus Price-Based Optimal Trading Mechanism Design in Microgrid

Increasing numbers of microgrids (MGs) and the maturing of technologies would allow MGs to engage in power market bidding as well as ensure their own consumption. A market base microgrid transaction mechanism design according to the blockchain (BC) platform is established in this study and the chimp optimization algorithm is employed for solving the optimal bidding process in the transaction. In this study, a price-based model is presented that organically integrates BC and MG for solving the issue of insufficient utilization of power in MG gaming competitions. Its convergence accuracy and search ability are high. In addition, two of the most significant players on the market will be utilized as research objects in order to build a real multi-sources mini-MG network to address the actual time energy costs issue. The example verification is used as a basis for the comparison evaluation.

Джерело живлення вимірювальних датчиків при виконанні експериментальних досліджень електротепломеханічної системи

The main part of scientific research is the results of the experiment, because they make it possible to establish the existing dependencies of the course of processes on a real object, confirm theoretical calculations and a mathematical model of an electrothermal-mechanical system. The work is devoted to the issue of experimental research of power supplies for measuring and recording equipment. According to the purpose, a technique was proposed by which experimental studies of the presence of pulses, noise and fluctuations in the output voltage of pulse and transformer power supplies were carried out. The influence of the deviation of the output voltage on the fluctuations of the voltage readings on the measuring and recording equipment has been investigated. Based on the results of experimental studies of power supplies, the proposed technique can be taken as a basis for selecting power supplies in accordance with the requirements for the required accuracy of reading indicators from the measuring equipment in accordance with their accuracy class, within the total error permissible for this type of experiment. A power source for measuring and recording equipment was selected for experimental studies of an electrothermal-mechanical system to intensify the process of methane formation in a biogas reactor in order to determine as accurately as possible the energy costs for biogas production, due to the fact that the process of producing biogas is long, therefore, a large error in determining energy costs affects an increase in actual energy costs in production in relation to the calculated and experimental data. The practical value of the work lies in the fact that the use of power supplies with a lower ripple of the output voltage in experiments will reduce the processing time of the obtained data arrays, increase the efficiency of the experiment and the accuracy of the revealed dependencies. The methodology presented in the work also makes it possible to more efficiently use financial resources for the purchase of devices in the preparation and conduct of scientific and experimental research. Keywords: power supply, voltage pulse, accuracy, scientific research, experiment, PeakTech

RESEARCH OF THE ACTUAL ENERGY CONSUMPTION OF THE MILITARY PERSONNEL OF THE ARMED FORCES OF UKRAINE TO SUBSTANTIATE THE CORRECTION OF THEIR DAILY DIET

The aim: Is to determine the actual energy costs of servicemen on the qualification course of special operations of the Armed Forces of Ukraine to substantiate the adequate nutritional and energy value of their diet. Materials and methods: The actual average daily energy consumption of 85 servicemen of the qualification course (hereinafter - Q-course) of special operations of AF of Ukraine was determined by time-table and instrumental methods. By laboratory, calculation and questionnaire methods, the compensatory possibilities of their actual nutrition were assessed. Results: The data obtained indicate that the highest indicators of energy expenditures among servicemen were during the first phase of selection of the Q-course at the level of an average value of 6853 ± 963.9 kilocalories (hereinafter - kcal) per day. At the same time, the calorie content of actual food consumed only by 55.7% provided compensation for the average daily energy costs. In this regard, we have developed and implemented "Organizational and Methodological Guidelines for Rational Nutrition of Servicemen of SOF of AF of Ukraine". Conclusions: The actual nutrition of the military personnel on the Q-course of SOF of AF of Ukraine does not fully compensate for their real energy losses. The nutritional and energy value of the daily diet requires revision and bringing it into line with the actual energy consumption, depending on the preparation phases.

THERMOMODERNIZATION OF BUILDINGS OF HIGHER INSTITUTIONS EDUCATION - PROBLEMS AND SOLUTIONS

The costs of maintaining budget buildings in Ukraine are 2-3 times higher than similar costs in the European Union, and for a number of reasons related to the outdated condition of external fences and utilities, sanitary and hygienic requirements in the premises are not met. The paper considers the results of the energy audit of the educational and administrative building of KNUTD in order to identify ways to reduce energy costs and improve the microclimate in the building. The energy condition of the building, the structure of energy costs are analyzed. In order to develop a set of energy saving measures, measurements of actual energy costs were made to determine the baseline level during technical and economic calculations. Energy audit was conducted using instrumental methods and with photo-fixation of visual inspection. The geometric, thermal and energy characteristics of the building have been specified. To increase the level of energy efficiency of the building, a complex thermal modernization is proposed, which includes work to increase the thermal resistance of external enclosing structures and modernization of engineering systems, financial and economic justification of the effectiveness of the proposed energy efficiency measures.Insufficient funding of budget institutions requires a systematic approach to solving the problem of improving the energy efficiency of student campuses, which will include not only the implementation of technical measures, but also information campaigns and organizational and management actions of the Energy Management Service and university management. An effectively functioning system of energy management of educational institutions is the foundation for sustainable development of the state; it is a set of measures that can have a significant effect on reducing Ukraine's energy dependence.

Time-of-use pricing model based on power supply chain for user-side microgrid

The user-side microgrid offers great potential for improving energy efficiency. This flexible and small-scale power system is characterized by multiple types of clean power supplies. The power supply chain can reveal the supply-demand relationships in the series of steps from power generation to consumption. However, electricity prices tend to vary and can significantly affect the actual energy costs to end-users and other entities in the power supply chain. In this study, we propose an optimization model of time-of-use pricing for the user-side microgrid from the perspective of power supply chain management. The objective of this model is to minimize the total cost of the power supply chain and optimize the charging-discharging behaviors of end-users. First, to reduce the impact of demand amplification and variation, we investigated the bullwhip effect of the power supply chain. Then, we considered distributed energy storage as an important component of the user-side microgrid and how electric power companies can utilize pricing strategies to optimize the charging-discharging behaviors of end-users. We performed experiments based on two scenarios that assumed end-users with and without distributed energy storage devices. A comparative analysis of the modelling results indicates that optimal time-of-use pricing can support the charging-discharging behaviors of residential users and reduce the cost of the entire electric power supply chain. The optimized time-of-use price is important for stability, flexibility, and efficiency improvement in both the user-side microgrid and the entire power supply chain.

Household Energy Costs and the Housing Choice Voucher Program: Do Utility Allowances Pay the Bills?

ABSTRACTUtility bills present a hidden threat to the affordability of a family’s housing—unknown before a household moves into a unit, and unpredictable from one month to the next. In theory, tenants receiving Housing Choice Vouchers are shielded from energy cost burdens through utility allowances built into rent subsidies. However, tenants may face actual energy costs that far outstrip allowances, effectively rendering their housing unaffordable. This study compares utility allowances with electric bills for over 19,000 Housing Choice Voucher households in four Florida cities and identifies household and unit characteristics associated with excessive costs. Nearly half of tenants in the sample faced bills in excess of posted allowances, with households renting single-family homes particularly at risk. On the other hand, state-sponsored affordable housing developments, such as those subsidized by the Low Income Housing Tax Credit, offered voucher tenants the chance to live in modern units with lower energy use and a better fit between costs and the utility allowance. The findings have implications for housing authorities and tenants seeking to reduce energy cost burdens.

Comparative efficiency of applying heat pumps within the system of disposal of the condensation heat of heat machines for heating ice arenas

The analysis of the application of two energy-efficient technologies for air heating of ice arenas is considered, such as the use of heat pumps and a system for partial utilization of heat of condensation of heat engines. The actual energy costs during the operation of two systems are studied, such as the consumption of heat and electricity from heat and power supply organizations, as well as the costs of modernization. The weaknesses and positive aspects of the studied systems for air heating of ice arenas are revealed. Comparison of the calculated data obtained as a result of calculations with the actual data obtained in the research institution in which the study is carried out. An example of actual effective modernization of existing engineering systems is shown, as a result of which the energy efficiency of existing systems is increased. Additionally, we have performed the calculation of reducing thermal pollution with introduction of the investigated systems.

Economic analysis of heat production in existing medium size combined heat and power plant, with respect to the CO2 allowances purchasing cost

This paper presents mathematical modeling and economic analysis of a medium size combined heat and power (CHP) operation, installed in Poland. The plant is equipped with steam boilers, extraction condensing turbine, and the grade type water boilers. The paper determines the most efficient mode of CHP operations. The economic efficiency analysis is performed for transient seasons, characterized by low demands for heating, which obliged production units to operate out of its nominal conditions at a lower efficiency. The developed method is also suitable for analyzing complex power plants, with a few energy equipments.The developed mathematical model for simulating CHP performance gives the possibility to select the boiler type, and assess the probability and efficiency of each configuration. The dedicated tool calculates the selected operation mode, heating power demand, and enables models comparison. The algorithm includes real equipment operational parameters, technical limitations, actual energy prices and costs regarding energy law acts. The performed analysis is up-to-date, due to a few aspects: permanently increased fossil fuels costs, low electric energy prices, growing costs of CO2 emission allowances, and high electricity production cost on turbine’s condensing section at steam parameters of T = 435 °C and p = 34 bar. A detailed cost analysis is performed on each product separately: thermal energy, electric energy from cogeneration and electric energy from condensation, during every hour, frequently. The calculation is carried every an hour for a period of 24 h, the energy balance is ensured during the calculation. The most important result of this study is a comparison of CHP to water boiler operation profitability, also including the net profit comparison. Furthermore, the cost of the CO2 emission is studied, for the production profitability in two scenarios, as the price increases from 7 EUR/tone to 15 EUR/tone and 30 EUR/tone.

The economic benefits of a green building – Evidence from Malaysia

Due to significant environmental and economic benefits associated with reduced energy consumption in green buildings, energy efficiency is considered a key driver for the green building movement. However, factors related to the actual building performance and future energy prices highly impact the actual energy cost of a green building. This research evaluates the actual economic performance of a green building in use in term of energy consumption and examines how different scenarios for energy price inflation would affect the cost saving associated with reduced energy consumption in the building throughout its whole life cycle. Based on actual data record, it is found in the research that the investigated green building saves around 71.1% of energy compared to the industry baseline. From life cycle perspective, the green building saves around 5756 kW h/m2 which corresponds to $2,796,451 at 1% average annual increase in energy price and it is more than fourfold at 5% average annual increase in energy price and reaches around $12,107,060. This research provides an empirical evidence for the economic benefits associated with reduced energy consumption in the green building.

Shifting Balance of Protein Synthesis and Degradation Sets a Threshold for Larval Growth Under Environmental Stress.

Exogenous environmental factors alter growth rates, yet information remains scant on the biochemical mechanisms and energy trade-offs that underlie variability in the growth of marine invertebrates. Here we study the biochemical bases for differential growth and energy utilization (as adenosine triphosphate [ATP] equivalents) during larval growth of the bivalve Crassostrea gigas exposed to increasing levels of experimental ocean acidification (control, middle, and high pCO2, corresponding to ∼400, ∼800, and ∼1100 µatm, respectively). Elevated pCO2 hindered larval ability to accrete both shell and whole-body protein content. This negative impact was not due to an inability to synthesize protein per se, because size-specific rates of protein synthesis were upregulated at both middle and high pCO2 treatments by as much as 45% relative to control pCO2. Rather, protein degradation rates increased with increasing pCO2. At control pCO2, 89% of cellular energy (ATP equivalents) utilization was accounted for by just 2 processes in larvae, with protein synthesis accounting for 66% and sodium-potassium transport accounting for 23%. The energetic demand necessitated by elevated protein synthesis rates could be accommodated either by reallocating available energy from within the existing ATP pool or by increasing the production of total ATP. The former strategy was observed at middle pCO2, while the latter strategy was observed at high pCO2. Increased pCO2 also altered sodium-potassium transport, but with minimal impact on rates of ATP utilization relative to the impact observed for protein synthesis. Quantifying the actual energy costs and trade-offs for maintaining physiological homeostasis in response to stress will help to reveal the mechanisms of resilience thresholds to environmental change.

Cable energy function of cortical axons.

Accurate estimation of action potential (AP)-related metabolic cost is essential for understanding energetic constraints on brain connections and signaling processes. Most previous energy estimates of the AP were obtained using the Na+-counting method, which seriously limits accurate assessment of metabolic cost of ionic currents that underlie AP conduction along the axon. Here, we first derive a full cable energy function for cortical axons based on classic Hodgkin-Huxley (HH) neuronal equations and then apply the cable energy function to precisely estimate the energy consumption of AP conduction along axons with different geometric shapes. Our analytical approach predicts an inhomogeneous distribution of metabolic cost along an axon with either uniformly or nonuniformly distributed ion channels. The results show that the Na+-counting method severely underestimates energy cost in the cable model by 20–70%. AP propagation along axons that differ in length may require over 15% more energy per unit of axon area than that required by a point model. However, actual energy cost can vary greatly depending on axonal branching complexity, ion channel density distributions, and AP conduction states. We also infer that the metabolic rate (i.e. energy consumption rate) of cortical axonal branches as a function of spatial volume exhibits a 3/4 power law relationship.

Measuring the Actual Energy Cost Performance of Green Buildings: A Test of the Earned Value Management Approach

Reduced energy consumption is a key aspect of the green building. Nonetheless, research indicates that there is a performance gap between the predicted and the actual energy performance once buildings are occupied, which implies a cost deviation from the anticipated energy cost performance. However, the cost deviation also might result from lower or higher energy rates than expected. As an appropriate research methodology for existing theory testing, case study research strategy was adopted to empirically examine the earned value management (EVM) approach to measure the actual life cycle cost performance of energy in green buildings. With slight methodological and terminological adaptations, it is found that the EVM approach can be applied to conduct a holistic cost performance measurement of the actual energy consumption in green buildings. The strength of the earned value approach is that it allows for detecting whether the energy cost saving or overrun results from lower or higher energy consumption, or from actual energy rate variations. The earned value approach allows for quantifying each cost variance independently, which is a significant aspect of actual energy cost performance measurement in green buildings.

Measured and estimated energy cost of constant and shuttle running in soccer players.

Players in team sports like soccer often make acceleration and deceleration movements, which are more energetically demanding than running at constant speed. The first aim of the present study was to estimate this difference in associated energy cost. To this end, we compared the actual energy cost of shuttle running to that of running at constant speed. In addition, since measuring oxygen consumption is not feasible during soccer, the study's second aim was to determine the validity of an indirect approach to estimate energy cost provided by di Prampero et al. (2005) using time-motion data obtained from a tracking system as input. Fourteen male amateur soccer players performed aerobic constant and continuous shuttle running at six different speeds (range = 7.5-10.0 km·h⁻¹) on artificial turf. Measured energy cost was compared to the energy cost estimated with di Prampero's (2005) equation using data from a local position measurement (LPM) system as input. As expected, measured energy cost was significantly higher (∼30%-50%) for shuttle running than for constant running (P < 0.001), and this difference increased with speed. For constant running, estimated energy cost was significantly higher (6%-11%) than measured energy cost, whereas for shuttle running, estimated energy cost was significantly lower (-13% to -16%) than measured energy cost. Shuttle running raised the player's energy cost of running compared to constant running at the same average speed. Although actual energy cost of constant running was significantly overestimated by di Prampero's approach using LPM data as input, actual energy cost of shuttle running was significantly underestimated.

An energy-efficient and client-centric data streaming technique on smartphones

Today's users extensively download video files on their wireless handheld devices, which are inherently power constrained. Experiments have shown that video downloading accounts for a large portion of the total energy cost of downloading and playing video files. In this paper, we present a novel, energy-efficient and purely client-centric video downloading algorithm with three tunable parameters namely, buffer size, low water mark and socket-reading size. By implementing the algorithm on a smartphone and measuring the actual energy cost, we show the impacts of the three parameters on the energy cost of video downloads. By tuning the buffer size, low water mark, and socket-reading, we observed energy savings to the extent of 60%, 64%, and 63%, respectively. By incorporating our algorithmic approach into the process of video downloading, mobile application developers will be better positioned to fine-tune their apps to reduce the total energy cost of downloading large files in general.