Energy Supply Costs Research Articles

Optimum utilization of hub energy micro-grids with micro-networking strategy of local biogas productions

In this paper, the optimal utilization of local biogas production in multi-energy systems is investigated. The micro-grid policy of local biogas production, to supply the variable demand of natural gas and also to convert it into electrical energy required by an energy hub micro-grid, along with other sources of scattered energy production and national electricity and gas networks, is one of the main goals of this paper. The multi-factor intelligent optimization method is considered to investigate the non-linear and heterogeneous optimization problem in the IEEE standard 33-bus energy hub microgrid. Most of the main indicators of interest are economic savings and minimization of operating costs. The multi-objective optimization method has been chosen as a method to solve the aforementioned non-linear and heterogeneous problem. Simulation has been done in GAMS software and the results of optimal load distribution of electric energy and natural gas supply for selected energy microhub have been explained and compared. The final results show a significant reduction of 46 % (2.8 thousand dollars per day) in operating costs. Significant reduction of energy flow between local network microhubs by 39.4 % is also one of the optimization results studied. Also, the Island performance of the local energy microhub has been simulated with the desired strategy. The cost of local energy microhub energy supply in island mode has decreased by 34 % (1.4 thousand dollars per day) compared to normal mode.© 2022 Published by.

Design and Long-Term Performance of a Pilot Wastewater Heat Recovery System in a Commercial Kitchen in the Tourism Sector

This paper assesses the performance of waste heat recovery from commercial kitchen wastewater in practice. A pilot study of heat recovery from the kitchen at Penrhyn Castle, a tourist attraction in North Wales (UK), is outlined. The pilot heat recovery site was designed and installed, comprising a heat exchanger, recirculation pumps, buffer tank and an extensive temperature/flow monitoring system for performance monitoring of the waste heat recovery system. Continuous monitoring was conducted for a period of 8 months, covering the 2022 tourist season. The recovered heat from the kitchen wastewater preheats the incoming cold freshwater supply and consequently reduces the amount of energy consumed for subsequent water heating. Retrofitting the pilot heat recovery system to the kitchen drains resulted in a heat saving of 240 kWh per month on average, a reduction of 928.8 kg CO2e per year, and a payback period for the investment costs of approximately two years, depending on the cost of energy supply. The presented results illustrate the potential of this form of renewable heat in reducing the carbon footprint of water heating activities in buildings and the hospitality sector.

Modeling thermal energy distribution and transmission networks for household consumption through comparative analysis.

The high costs of energy supply and variable energy demands in consumption units, especially domestic consumption in different time frames, have accelerated technological developments for the proper use of energy resources to reduce energy consumption. The design of a distribution network for consumption depends on environmental conditions, equipment locations, consumer demands, consumption simultaneity factor, and some other parameters. These factors can mitigate energy loss in transmission networks. This study analyzes effective factors in the thermal energy distribution and transmission systems from generators to household consumers by considering the energy consumption rates in units based on a mathematical model to increase energy consumption in teams and rely on consumption during transmission. For this purpose, energy demands were evaluated in consumption units in a sample one-year project. The results were employed to design an optimal network for transferring energy from generators to consumers by modeling the distribution system. In this study, the thermal energy distribution and transmission network for domestic consumption was assessed and ranked have been assessed and ranked through single-stage distribution (SSD), multistage distribution (MSD), and MSD with the flow bypass method. The results of simulating the MSD system with the flow bypass method indicated the optimal performance of the proposed system in both consumer and generator sectors. This method also reduced fuel consumption by 6.09% and increased electricity consumption of the transmission network by 95% compared with single-stage transmission networks. Moreover, the method yielded a 6.03% reduction in the total cost of energy consumed to provide the thermal load of the building compared with SSD on a yearly basis.

An integrated financial and environmental evaluation framework to optimize residential photovoltaic solar systems in Australia from recession uncertainties

This study assesses the financial viability and environmental evaluation of Photovoltaic (PV) panels from the perspective of the recent economic recession due to the Russia-Ukraine war. The financial viability of PV installation is calculated based on the estimated price, solar rebates, feed-in tariff, energy supply cost, and other evaluation parameters available at the assessment time. This calculation implicitly assumes variable discount rates (4%, 7%, and 12%) to show how the future will unfold and its correlations with design parameters. Details of economic appraisal integrating current inflation, rebates, and incentives of solar systems have been analyzed for the first time in this study. Financial indicators reveal the advantages of installing a grid-connected solar system (SS) over a solar battery storage system (SSWB). Compared to other installation systems, the lowest payback (PB) and highest internal rate of return (IRR) are observed for a 7 kW grid-connected solar system. Relative uncertainties of solar installation systems represent the necessity of government subsidies (r = -0.602) for solar storage batteries. LCA signifies the energy-intensive process of manufacturing metallurgical-grade (MG) silicon is the primary cause of significant greenhouse gas (GHG) emissions and cumulative energy demand (CED) for PV panels. A potential amount of metal and fossil fuels is depleted for interconnective components of solar installation systems. Amorphous solar panels exhibit lower impacts than polycrystalline, but further upgradation in service life is required to become cost-effective and cope with current inflation.

Performances Analysis and Comparison of Active and Hybrid Harmonic Filter in Photovoltaic Water Pumping System

As an agriculturally based country, many rivers pumping stations are implemented in Myanmar. Currently, these pumping stations are operated with utility supply or diesel engines. For reliable energy supply and energy cost saving, the solar powered river pumping stations are now carried out in Myanmar. Most of these pumping stations are located at the dry zones especially at Magway, Mandalay and Sagaing Divisions. The main problem with solar powered river pumping station is the harmonic induced due to DC/DC boost converter and three phase inverters. Harmonics are the important problem in solar river water pumping system as they can shorten the life span of pumping motors and vibrations. Thus, harmonic filters become the main function of these system. In this research, the harmonic mitigation for Kanni river pumping system is executed using active and hybrid harmonic filter and their performances are compared. In this work, solar river water pumping system is designed firstly, and then modelled and simulated using MATLAB/Simulink. Harmonic contents and mitigation performances of each filter are analysed using Fast Fourier Transform (FFT) tool.

Operational optimisation of integrated campus energy systems considering integrated demand response

Against the backdrop of the rapid development of the energy internet in the park, the multi energy coupling and complementary characteristics of integrated energy systems provide more space for optimizing the participation of demand parties in their coordinated planning. Establishing a effective demand side model with multiple energy flows and response types has become an effective means to improve system performance. For this reason, this paper takes the comprehensive energy system of the park with multiple electricity, gas, heat and cold complements as the research object, establishes a complete model of multi load and multi type demand response based on the improvement, incentive and substitution of real-time pricing mechanism, and uses multi-attribute decision-making method to obtain the optimal configuration of the system by establishing an optimization framework for iteration of the main problem and sub problem. The simulation results show that compared with traditional energy supply system configurations, the complete model established in this paper for various controllable resources on the demand side achieves the coordinated and complementary operation of the system’s multi energy and low-carbon economy, fully utilizing the regulatory potential of the demand side, effectively reducing load fluctuations and energy supply costs.

Optimal design method and benefits research for a regional integrated energy system

Regional integrated energy systems (RIES) have garnered increased attention because they highly utilize renewable energy, comprehensive efficiency, and flexible operation. However, the current research on RIESs is mainly based on burning natural gas and supplemented by renewable energy, which will consumes much primary energy and generates corresponding carbon emissions. Therefore, a RIES contained various renewable energy sources and station energy sharing was constructed in this paper. Both the collaborative optimization model, which considered the operating parameters and system configuration, and the hierarchical optimization model, which optimizes the equipment configuration at the upper layer and the operational parameters at the underlayer, were constructed, respectively. Taking a multi-function low-carbon park as an example, the isolated integrated energy system (IIES) and RIES performances were explored. Finally, the operation cost, carbon emission, and interactive power in the separated production system, IIES and RIES were analyzed and discussed from a long-short time scale perspective. The results showed that the carbon emission, interactive power, and energy supply cost of the RIES's unit area are 7.62 kg/m2, 10.07 kWh/m2, and 40.55 CNY/m2, respectively. Long time scale perspective (Years or months), RIESs could significantly reduce carbon emissions and interactive power. However, on a short time scale viewpoint (Hours), the system's instantaneous energy conservation and carbon reduction effect was general; meanwhile, the maximum grid-connected power in IIES and RIES was 2617.7 and 2712.0 kW, respectively.

Collaboration model between Distribution System Operator and flexible prosumers based on a unique dynamic price for electricity and flexibility

The paper presents an innovative coordination model between flexible final customers and an aggregator in providing flexibility service to the Distribution System Operator called Coordination Via Aggregator (CVA). The problem is formulated as a stochastic two-stage bilevel model in which the leader acts as both the aggregator and the supplier, and maximizes its profit by determining the price signal for flexible final customers composed of energy-based component and the incentive for service provision. Final users, modeled as followers in the lower level of the model, minimize their costs following the price signal from the upper level. The aggregator in this model is a non-zero-profit market entity, i.e., the price determined by the aggregator covers the balancing costs, the energy supply costs and at the same time incentivizes flexible customers to adequately change their consumption patterns. The CVA results are compared with the Direct Service Activation (DSA) approach in which final customers have a predefined two-tariff pricing option and receive a fixed amount of annual network charges discount for participating in the direct load control program. Based on the small-scaled and medium-scaled MV network results, customers with Renewable Energy Sources (RES) face lower electricity costs when providing flexibility service under the CVA approach compared to DSA (15% lower costs in small-scaled network). However, the results show that prosumers with high PV capacity (inject more energy in the grid than withdraw on an annual level) if not involved in providing flexibility, are more prone to signing up for a contract with the aggregator achieving lower electricity cost compared to two-tariff pricing option, however if they are providing flexibility services, direct load control results in 14% lower costs. In contrast, providing flexibility service under DSA with reduced network charges results in 9% lower cost in small-scaled and 16% in medium-scaled networks for final users without RES.

Modeling and Analysis of Wave Energy Harvester with Symmetrically Distributed Galfenol Cantilever Beams.

In response to the challenges of difficult energy supply and high costs in ocean wireless sensor networks, as well as the limited working cycle of chemical batteries, a cylindrical wave energy harvester with symmetrically distributed multi-cantilever beams was designed with Galfenol sheet as the core component. The dynamic equation of the device was established, and ANSYS transient dynamic simulations and Jiles-Atherton hysteresis model analysis were conducted to develop a mathematical model of the induced electromotive force of the Galfenol cantilever beam as a function of deformation. Experimental validation demonstrated that the simulated results of the cantilever beam deformation had an average error of less than 7% compared to the experimental results, while the average error between the theoretical and experimental values of the induced electromotive force of the device was around 15%, which preliminarily verifies the validity of the mathematical model of the device, and should be subject to further research and improvement.

Multi-parameter optimization design method for energy system in low-carbon park with integrated hybrid energy storage

Low-carbon parks composed of concentrated and contiguous low-carbon buildings has the characteristics of the high proportion of renewable energy penetration and low-carbon operation, requiring the transformation of relevant energy supply systems from being centralized to being centralized and distributed. However, the centralized and distributed energy supply method faces low levels of renewable energy utilization. Therefore, in this study, a low-carbon park energy system is constructed with a core of photovoltaics, wind power, lithium batteries, and heat storage tanks. A multi-parameter collaborative optimization method is proposed with the goals of cost reduction, carbon reduction, and independence by considering the parameters of equipment configuration and operation. The comprehensive benefits of a low-carbon park energy system under each low-carbon park are explored. The advantages of the system in terms of monthly carbon emission intensity, operation cost, maintenance cost, and interactive power are analysed. For the system, the balance of its energy supply and demand on a typical day and the role of energy storage in improving its utilization of renewable energy are analysed. Finally, the feasibility and benefits of the system's energy supply in different climate zones are further studied. The results show that the energy supply cost, carbon emissions, and interactive power are 31.0 CNY/m2, 4.1 kg/m2, and 2.4 kWh/m2, respectively, resulting in the best benefits for a unit area in a low-carbon park energy system in a high-rise residential park (Beijing). Energy storage can effectively improve the levels of renewable energy utilization, energy conservation and carbon reduction in the system. The low-carbon park energy system proposed in this article can significantly contribute to reducing carbon emissions in the construction industry.

Reliability-constrained Bi-level collaborative planning of distribution network and micro-energy grid

In order to make full use of the potential reliability value of micro-energy grid (MEG) to defer further grid investment and reduce the energy supply cost, this paper proposes a bi-level collaborative planning model for distribution network and micro-energy grid considering network reliability. With consideration of reliability difference, price signals are used to guide the optimal balance between supply and demand. The upper-level aims at maximizing the profit of the distribution network while optimizing the pricing and expansion planning strategies of the distribution network. And the lower-level aims to minimize the cost of micro-energy grid as well as optimizing the planning and operation strategies of micro-energy grid. A 14-node distribution network system is utilized to conduct the simulation, the results show that the proposed method can improve the economic benefits of distribution network and micro-energy grid and reduce the overall energy supply cost on the premise of meeting users' demands. In addition, with the increase of users' reliability requirements, the effect of reducing the overall energy supply cost is more significant.© 2017 Elsevier Inc. All rights reserved.

Designing multi-objective electric and thermal energy management system of microgrid in the presence of controllable loads and electric vehicles

The global electricity network and natural gas have been developed worldwide. So far, various investigations in relation to energy infrastructures have been performed; however, the combination of these systems has not been examined much. For this reason, electric and thermal loads have been interconnected by CHP units, and the combined study of power and heat has helped the operator to propose a more optimal structure for energy management. Therefore, integrating different energy carriers and using the benefits of each one can increase the efficiency and reliability along with optimizing system performance. Such a capability in structure and operation requires a comprehensive framework to describe the effects of combining different energy carriers on the economic and environmental indicators of energy systems. In this paper, the microgrid has been modeled as an energy hub in order to combine different energy carriers and perform conversions in them to provide the optimal electric and thermal load required by the consumer. This structure has been created by managing the incoming carriers of gas, electricity and renewable energy and managing their conversion and storage in order to minimize the cost of energy supply and environmental pollutants. In addition to managing generation units, in order to improve the performance of the microgrid and help the operator of the microgrid, a responsive load management strategy and charging and discharging of electric vehicles have been proposed. Epsilon constraints and fuzzy decision-making methods have been used to solve this issue. The results of the study indicated that in the optimal state with the application of responsive loads, the total cost of operation has been reduced by more than 6% and the cost of environmental pollutants has been mitigated by about 13%.

Holistic plug-n-play autonomous solar system integration: a real-life small-scale demonstration—a practical approach

Autonomous PV systems offer a substitute for or a safety net against the transmission and distribution companies’ rising and expanding electricity delivery fees. Across the world, delivery fees have climbed by about 3% annually while the cost of energy supply has only gone up by 5% over the past 15 years. In this paper, the drawbacks of PV system integration are highlighted while introducing a unique autonomous PV system. The system is also constructed in a reproducible way so that it can be duplicated. Replicability is showcased by the presentation of two separate PV systems that were created and evaluated using the same methodology. One system uses Si-based conventional photovoltaics, while the other uses dye-sensitized solar cells. The systems that are being offered also support remote connections, allowing all of the data from the PV system to be transmitted to a single endpoint (e.g., a visualization platform). Moreover, the system’s batteries were modified to accommodate the two PV systems. Finally, experimental results showcase the operability of the proposed architecture.

AUTOMATED RESOURCE MANAGEMENT SYSTEM FOR THE UTILITY SECTOR BASED ON WIRELESS SENSOR NETWORKS

The subject of this study is methods, tools and automated resource management systems for the housing and communal sector. The object of research is the process of controlling resource consumption at housing and communal facilities. The aim of the study is to develop an automated resource management system for the utility sector based on wireless sensor networks. To achieve this goal, the following tasks were solved: a review and analysis of existing methods, tools and automated resource management systems; selection of system components based on technical requirements and taking into account the selected LoRaWAN wireless connection technology; development of a structural diagram and algorithm for the operation of an automated resource management system based on wireless sensor networks; modelling of the process of managing the resources of the utility sector using a wireless sensor network based on t The following methods are used in the work: critical analysis of LoRa technology and other wireless IoT technologies, FOREL and -means clustering methods. The following results were obtained: a general description of the automated resource management system was carried out, its composition and main tasks were determined, and technical requirements for it were established, wireless data transmission technology was selected, on the basis of which the automated resource management system was built, an in-depth comparative analysis of the most effective modern wireless technologies – LoRaWAN and NB-IoT – was carried out, system components were selected, a structural diagram and algorithm for the automated resource management system were developed, and the process of the automated resource management system was modelled. Conclusions: the application of the proposed automated resource management system provides high-quality control of energy consumption at the facilities of the housing and communal sector, makes it possible to control their volume, monitor and analyse energy consumption data, and manage the entire energy supply network as a single system, which is especially necessary in martial law. This approachallows rationalising the consumption of resources by household consumers, which means that the financial costs of energy supply will decrease and the level of energy savings in the country will increase.

Novel Decentralized Peer-to-Peer Gas and Electricity Transaction Market between Prosumers and Retailers Considering Integrated Demand Response Programs

This paper proposes a novel peer-to-peer (P2P) decentralized energy market consisting of retailers and prosumers considering integrated demand response (IDR). Retailers can trade electrical energy and gas with prosumers in a P2P way to maximize their welfare. Since they are equipped with electrical storage and power self-generation units, they can benefit from selling power not only to the upstream network but also to prosumers. In peer-to-peer transactions, the prosumers purchase electricity as well as gas from retailers. Because of their access to the competitive retail market, including some retailers, they enjoy more freedom to reduce their energy supply cost. In addition, the prosumers are equipped with an energy hub consisting of combined heat and power (CHP) units and electric pumps, allowing them to change their energy supply according to price fluctuations. Furthermore, they have some changeable electrical and thermal load enabling them to change their load if needed. To clear the proposed P2P decentralized market, a fully decentralized approach called the fully decentralized alternating direction method of multipliers (ADMM) is applied. This method does not require a supervisory entity and, thus, preserves the players’ private information. The numerical studies performed on a system with two retailers and multiple prosumers demonstrate the feasibility and effectiveness of the proposed decentralized market. The results also show that the proposed decentralized algorithm achieves the optimal global solution, compared with the centralized approach.

Sector coupling of electricity, transport and cooling with high share integration of renewables in Indonesia

Sector coupling improves energy system efficiency by maximising potential synergies among energy sectors. This paper aims to assess the sector coupling of electricity, transport, and cooling on the Java and Bali islands, Indonesia. Future energy systems in 2040, focussing on decarbonised electricity sector with high electric vehicles deployment and district cooling penetration, were simulated using EnergyPLAN. A bottom-up calculation approach was applied to determine demand in the transport sector. In the cooling sector, geospatial analysis was employed to quantify cooling demand and locate potential district cooling networks in Jakarta. Six scenarios were explored based on their energy demand and supply characteristics. Modelling results show that the sector coupling of three sectors could reduce primary energy supply (PES), CO2 emissions and annual costs. The most suitable scenario has about 8% lower PES, 14% lower CO2 emissions and 2% less annual costs compared to the business-as-usual scenario. Results also show that transport electrification could only effectively and significantly decrease CO2 emissions if its electricity demand is produced from renewables. Transport electrification with large scale integration of renewables could also lower the annual costs by decreasing fossil fuel costs in the transport and electricity sectors.

Investigating pathways to a net-zero emissions building sector in the European Union: what role for the energy efficiency first principle?

European Union (EU) legislation is increasingly embracing the energy efficiency first (EE1st) principle. This principle seeks to prioritise energy efficiency measures whenever these involve lower costs to society than generators, networks and other energy supply options while achieving the same outcomes. This study contributes to the quantitative evidence on the relevance of EE1st by modelling the impact of moderate to ambitious end-use energy efficiency measures on energy supply and the associated system cost under a net-zero greenhouse gas emissions constraint by 2050. These measures focus on the EU building sector and include both building retrofits (e.g. wall insulation) and efficient products (e.g. lighting). The results indicate that implementing more ambitious energy saving measures reduces the total electricity, heat and hydrogen capacities needed to achieve the net-zero target. Reducing energy use in buildings by at least 21% between 2020 and 2050 is essential to avoid excessive energy supply costs. This requires actions that go well beyond business-as-usual trends. Reductions of around 30% could be justified on the grounds of (i) high fossil fuel prices and (ii) multiple impacts (e.g. health benefits). Overall, the outcomes provide reasonable justification for the EE1st principle. To put the principle into practice, policy actions such as doubling building renovation rates and setting higher energy efficiency targets are key.

Optimal planning for industrial park-integrated energy system with hydrogen energy industry chain

Establishing an industrial park-integrated energy system (IN-IES) is an effective way to reduce carbon emission, reduce energy supply cost and improve system flexibility. However, the modeling of hydrogen storage in traditional IN-IES is relatively rough. In order to solve this problem, an IN-IES with hydrogen energy industry chain (HEIC) is proposed in this paper. Hydrogen production, transportation, and storage technologies are applied in HEIC. Firstly, a novel long-term hydrogen storage model considering different time steps is presented. Secondly, hydrogen compressor models considering different pressure ratios are further employed. On this basis, the impact of the HEIC on the planning and operation results of IN-IES is studied. Finally, the superiority and the effectiveness of the proposed model and planning method are verified by simulation cases.

Bi-Level Multi-Objective Planning Model of Solar PV - Battery Storage-Based Ders in Smart Grid Distribution System

The Bi-level Multi-Objective Planning Model of Solar PV-Battery Storage-Based DERS in Smart Grid Distribution System is a research paper that proposes a planning model for the implementation of distributed energy resources (DERs) in a smart grid distribution system. The model is designed to optimize the deployment of solar PV and battery storage systems in the grid, while taking into account various technical, economic, and environmental factors. The proposed planning model is based on a bi-level multi-objective optimization approach, which considers both the objectives of the utility and the objectives of the DER owners. The upper-level objective is to minimize the total cost of energy supply to the grid, while the lower-level objective is to maximize the revenue of the DER owners. The model is implemented using a genetic algorithm, which is used to search for the optimal solution.
 The model is also capable of considering the uncertainties associated with solar PV and battery storage systems, such as weather conditions and battery degradation. The results of the study show that the proposed planning model can effectively optimize the deployment of solar PV and battery storage systems in a smart grid distribution system. The model is also shown to be robust to various uncertainties associated with DERs, such as weather conditions and battery degradation. Overall, the proposed planning model provides a valuable tool for the implementation of distributed energy resources in a smart grid distribution system. By optimizing the deployment of DERs, the model can help to reduce the cost of energy supply, while also improving the reliability and environmental performance of the grid.
 This project describes the multi objective battery sizing and storage system for grid connected system using renewable energy solar and wind system.

Retracted: Integrated modeling of food–water–energy nexus for maximizing water productivity

ABSTRACT One of the needs of a sustainable decision-making system in agriculture is to determine the role of energy in the food production cycle. Wind energy turbines can be built in agricultural fields for groundwater exploitation and reduce the cost of energy supply for the pumping system. This study was conducted to evaluate the effect of wind energy and economics on sustainable planning of agricultural water resources. A multiobjective framework was developed based on the nondominated sorting principle and water cycle optimizer. Maximization of benefit per cost ratio for the total cropping pattern and minimization of energy consumption for the growing season were addressed as the objectives of the nonlinear problem. The prediction of biomass production was made by simulating a hybrid structure between the soil moisture balance in the root zone area and the development of the canopy cover of each crop. The results showed that the objectives of the problem have been met by irrigation planning using climatic constraints and drought stresses. About 35% of the total water requirement of plants with a higher harvest index (watermelon, melon, etc.) is in the maturing stage of the shade cover.