Optimal Economic Modelling of Hybrid Combined Cooling, Heating, and Energy Storage System Based on Gravitational Search Algorithm-Random Forest Regression

The hybridization of two or more energy sources into a single power station is one of the widely discussed solutions to address the demand and supply havoc generated by renewable production (wind-solar/photovoltaic (PV), heating power, and cooling power) and its energy storage issues. Hybrid energy sources work based on the complementary existence of renewable sources. The combined cooling, heating, and power (CCHP) is one of the significant systems and shows a profit from its low environmental impact, high energy efficiency, low economic investment, and sustainability in the industry. This paper presents an economic model of a microgrid (MG) system containing the CCHP system and energy storage considering the energy coupling and conversion characteristics, the effective characteristics of each microsource, and energy storage unit is proposed. The random forest regression (RFR) model was optimized by the gravitational search algorithm (GSA). The test results show that the GSA-RFR model improves prediction accuracy and reduces the generalization error. The detail of the MG network and the energy storage architecture connected to the other renewable energy sources is discussed. The mathematical formulation of energy coupling and energy flow of the MG network including wind turbines, photovoltaic (PV), CCHP system, fuel cell, and energy storage devices (batteries, cold storage, hot water tanks, and so on) are presented. The testing system has been analysed under load peak cutting and valley filling of energy utilization index, energy utilization rate, the heat pump, the natural gas consumption of the microgas turbine, and the energy storage unit. The energy efficiency costs were observed as 88.2% and 86.9% with heat pump and energy storage operation comparing with GSA-RFR-based operation costs as 93.2% and 93% in summer and winter season, respectively. The simulation results extended the rationality and economy of the proposed model.

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Capacity Optimization of Energy Storage Unit in Distributed Generation System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.608-609.1116 ◽

2012 ◽

Vol 608-609 ◽

pp. 1116-1119

Author(s):

Cai Yun Guo ◽

Hong Bin Wu

Keyword(s):

Energy Storage ◽

Distributed Generation ◽

Search Algorithm ◽

Generation Model ◽

Storage Unit ◽

Energy Storage Unit ◽

Optimal Capacity ◽

Battery Energy ◽

Pv Generation ◽

System Power

The photovoltaic(PV) generation model and the wind power generation model are introduced in this paper. Taking the best economy and reliability of system operation as the objective functions and the system power balance and battery storage performance indices as the constraints, the optimal capacity of battery energy storage can be determined with the Tabu search algorithm. With the example system, the simulation results show that the proposed models and the algorithm are correct.

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Optimization Location Selection Analysis of Energy Storage Unit in Energy Internet System Based on Tabu Search

International Journal of Software Engineering and Knowledge Engineering ◽

10.1142/s0218194019400072 ◽

2019 ◽

Vol 29 (07) ◽

pp. 941-954

Author(s):

Haitian Chen ◽

Yan Zhao ◽

Yanwei Ji ◽

Shunjiang Wang ◽

Weichun Ge ◽

...

Keyword(s):

Energy Storage ◽

Tabu Search ◽

Industrial Revolution ◽

Search Algorithm ◽

Reference Value ◽

Tabu Search Algorithm ◽

Storage Unit ◽

Energy Internet ◽

Location Selection ◽

Energy Storage Unit

Energy Internet has become the theme of the new round of industrial revolution. Energy storage, as a key technical support for the development of energy Internet, has always been of concern to numerous people, since the energy Internet consists of various energy networks that can provide energy support for different energy subnetworks. Therefore, the energy storage unit is in a crucial position in the entire energy network. This paper points out the importance of various energy storage technologies in the energy Internet. An energy storage unit location analysis method based on Tabu search algorithm is proposed to reduce the network energy loss, pressing mimizing network loss as constraint on the location of the energy storage unit as a search target. The Tabu search algorithm is programmed using Matlab and is used to search for the location of energy storage unit in the IEEE example. Besides, the optimal node solution is obtained, which verifies the feasibility of this algorithm to analyze the location selection of energy storage unit in the energy Internet. This paper has some reference value for the coordinated optimization of energy storage units in the energy Internet.

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Energy Self-Sufficient Livestock Farm as the Example of Agricultural Hybrid Off-Grid System

Energies ◽

10.3390/en14217041 ◽

2021 ◽

Vol 14 (21) ◽

pp. 7041

Author(s):

Grzegorz Augustyn ◽

Jerzy Mikulik ◽

Rafał Rumin ◽

Marta Szyba

Keyword(s):

Renewable Energy ◽

Energy Storage ◽

Energy Flow ◽

Renewable Energy Sources ◽

Biogas Plant ◽

Energy Sources ◽

Storage Unit ◽

Energy Storage Unit ◽

Livestock Farm ◽

The One

Contemporary agriculture has become very energy-intensive and mainly uses electricity, which is needed for technological processes on livestock farms. Livestock faeces are burdensome for the environment due to the release of methane into the atmosphere. This article presents the concept of a self-sufficient livestock farm as an off-grid energy circuit that is a part of the agricultural process. The key idea is to obtain an energy flow using the concept of a smart valve to achieve a self-sufficient energy process based on a biogas plant, renewable energy sources, and energy storage. During the production process, a livestock farm produces large amounts of waste in the form of grey and black manure. On the one hand, these products are highly harmful to the environment, but on the other, they are valuable input products for another process, i.e., methane production. The methane becomes the fuel for cogeneration generators that produce heat and electricity. Heat and electricity are partly returned to the main farming process and partly used by residents of the area. In this way, a livestock farm and the inhabitants of a village or town can become energy self-sufficient and independent of national grids. The idea described in this paper shows the process of energy production combining a biogas plant, renewable energy sources, and an energy storage unit that enable farmland to become fully self-sufficient through the energy flow between all constituents of the energy cycle being maintained by a smart valve.

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Service life tests for storage batteries used in islanded power systems with renewable energy sources

Proceedings of Irkutsk State Technical University ◽

10.21285/1814-3520-2021-4-463-477 ◽

2021 ◽

Vol 25 (4) ◽

pp. 463-477

Author(s):

S. G. Оbukhov ◽

I. А. Plotnikov ◽

V. G. Маsolov

Keyword(s):

Renewable Energy ◽

Energy Storage ◽

Service Life ◽

Renewable Energy Sources ◽

Stress Factors ◽

Energy Sources ◽

Storage Unit ◽

Energy Storage Unit ◽

Storage Batteries ◽

Charge Discharge

We investigated the service life of storage batteries to provide recommendations on the design of energy storage systems used in islanded energy systems based on renewable power sources. The service life of maintenance-free, sealed lead-acid batteries produced by absorbed glass mat (AGM) technology was determined by endurance tests carried out by repeated charge/discharge cycles according to specified load profiles, implemented at a specialized Chroma Test System station. Three battery load profiles were simulated: one for the standard DC charge/discharge mode, and two for the charge/discharge modes from renewable energy sources. To this end, the actual data obtained from monitoring the operating modes of a wind power plant were used. It was found that the battery service life depends on the intensity of stress factors. Among them, the throughput factor has the most pronounced influence on the battery lifespan. To extend the service life of storage batteries, it is proposed to separate the charge/discharge modes in time. For batteries operated on renewable energy profiles, this approach decreases time intervals between full charges and at low battery levels, which increases the battery service life by 14%. A solution to designing an energy storage system for microgrids was proposed, which consists in the use of a combined double-circuit energy storage unit. An experimental prototype of such a unit with a power of 15 kW was developed. The use of a combined energy storage unit in the microgrid system: increases the battery service life by 20–30% compared to analogues; improves the static and dynamic stability of the local energy system with a response time of no more than 50 ms towards power change; allows a fuel replacement level of at least 25%; reduces the electricity cost by 25–30%.

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