THERMAL ENERGY STORAGE SYSTEM FOR GRID

APPLICATION

A Seminar Report
Submitted in Partial Fulfillment of
the Requirements for the Award of the Degree of

BACHELOR OF TECHNOLOGY
in
ELECTRICAL AND ELECTRONICS ENGINEERING
from

APJ Abdul Kalam Technological University

Submitted By
GOKUL M. (REG. NO. LMEA21EE019)

MEA Engineering College

Department of Electrical and Electronics Engineering
Vengoor P.O, Perinthalmanna, Malappuram, Kerala-679325
November 2024
 MEA Engineering College
Vengoor, Perinthalmanna, Kerala

Department of Electrical and Electronics Engineering

CERTIFICATE
This is to certify that the seminar report on “THERMAL ENERGY STORAGE SYSTEM
FOR GRID APPLICATION” is a bonafide record of the work done by GOKUL M.
(LMEA21EE019) in partial fulfillment for the award of the degree of Bachelor of
Technology in Electrical and Electronics Engineering to the APJ Abdul Kalam
Technological University.

Guide: Seminar Coordinator: Head of the Department:

Mr. MUHAMMED ASLAM. KV Mr. MUHAMMED ASLAM. KV Dr. FEBINA BEEVI P
Assistant Professor Assistant Professor Associate Professor
Dept. of EEE Dept. of EEE Dept. of EEE
MEA Engineering College MEA Engineering College MEA Engineering College
Perinthalmanna Perinthalmanna Perinthalmanna
THERMAL ENERGY STORAGE SYSTEM FOR GRID
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DECLARATION

I hereby declare that the seminar report “THERMAL ENERGY STORAGE SYSTEM FOR
GRID APPLICATION”, submitted to the APJ Abdul Kalam Technological University,
Kerala, in partial fulfillment of the requirements for the award of the degree of Bachelor of
Technology in the Electrical and Electronics Engineering, is a record of the bonafide work
carried out by me under the supervision of Mr. GOKUL M., Assistant Professor in
Department of Electrical and Electronics Engineering. The report is in my own words and
where ever ideas or words of others have been included, I have adequately and accurately
cited and referenced the original sources.
I also declare that I have adhered to ethics of academic honesty and integrity and have not
misrepresented or fabricated any data or idea or fact or source in my submission.
I understand that any violation of the above will be a cause for disciplinary action by the
institute or the University and can also evoke penal action from the sources which have not
been properly cited or from whom proper permission have not been obtained.
This report has not been previously submitted or will not be submitted, either in part or in
full, for the award of any degree or diploma in this institute or any other institute.

Place Signature

Date GOKUL M.

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ACKNOWLEDGEMENT

I express my deep and sincere gratitude to my guide Mr. Muhammed Aslam. KV,
Assistant Professor, Department of Electrical and Electronics Engineering, MEA Engineering
college, Perinthalmanna for the kind co-operation and guidance for the completion of my
seminar.
I express my sincere gratitude to Dr. G. Ramesh, respected Principal for giving me
an opportunity and for the facilities provided for the completion of my seminar.
I also extend my gratitude to seminar coordinators, Dr. Febina Beevi P, Associate
Professor & HOD, and Mr. Muhammed Aslam. KV Assistant Professor, Department of
Electrical and Electronics engineering, MEA Engineering College, Perinthalmanna for their
kind co-operation for preparing and presenting this seminar.
I also express my sincere thanks to all staff member of Electrical and Electronics
Department for their kind co-operation they have rendered.
I thankfully acknowledge my parents, my friends and all others for their support and
encouragement.
Above all, I would like to thank The Almighty for showering his grace upon me.

GOKUL M.

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ABSTRACT

The global push towards carbon neutrality by 2030 is leading to the shutdown of coal power
plants, which in turn is causing significant unemployment and economic instability. The
current reliance on lithium-ion battery storage systems for grid energy storage is proving to be
insufficient and unsustainable. This paper explores the issue of energy storage for grid
applications and aims to find a sustainable solution.

The discussed system utilizes thermal energy storage, where electricity is converted to
thermal energy during off-peak hours and then back to electrical energy during peak hours.
This energy is stored in a specially designed cubical structure. The study optimizes the
system's performance over a 24-hour period, showing promising results in terms of
consistency and reliability.

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CONTENTS
CHAPTER NO. TITLE PAGE NO

DECLARATION ii

ACKNOWLEDGEMENT iii

ABSTRACT iv

LIST OF FIGURES vi

LIST OF TABLES vii

1 INTRODUCTION 1
2 METHODOLOGY 3

2.1 INTRODUCTION 3

2.2 BLOCK DIAGRAM 3

2.3 SCHEMATIC DIAGRAM 4
2.4 EQUATIONS 5
2.5 FINITE ELEMENT ANALYSIS 6
3 SIMULATION AND RESULTS 7
3.1 INTRODUCTION 7
4 CONCLUSION 10
REFERENCES 11

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LIST OF FIGURES

FIGURE NO. NAME OF FIGURES PAGE NO

2.2.1 BLOCK DIAGRAM 3

ENCLOSURE OF THERMAL ENERGY
2.3.1 4
STORAGE SYSTEM
GEOMETRY OF THERMAL ENERGY
2.3.2 4
STORAGE SYSTEM
CROSSECTION OF THERMAL ENERGY
2.3.3 4
STORAGE SYSTEM
3.1.1 TEMPERATURE CONTOUR OF THE CUBE 7
TEMPERATURE CONTOUR OUTSIDE THE
3.1.2 7
CUBE
3.1.3 THERMAL RADIATION FROM THE CUBE 7
3.1.4 PRESSURE CHARACTRISTICS 8

3.1.5 TEMPERATURE vs POSITION 8

3.1.5 WALL TEMPERATURE vs POSITION 9

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CHAPTER 1
INTRODUCTION

Over the past decade, the green concept has gained significant momentum, transforming
various industries, particularly transportation and logistics, towards electric systems. This
shift has been driven by the increasing demand for energy and the urgent need to reduce
carbon emissions. However, this transition has also led to substantial unemployment, as
traditional coal power plants are phased out. Current grid storage systems, primarily reliant on
lithium-ion (Li-ion) batteries, are proving inadequate. These batteries pose several issues,
including fire hazards, limited charging cycles, and reliance on expensive and rare earth
metals, making them unsustainable in the long run. In response to these challenges, the
concept of thermal energy storage, which has been around for some time, is now being
reconsidered for grid-level applications. This paper introduces a novel technique for thermal
energy storage that can retain energy for up to 24 hours with minimal losses. This system not
only promises to provide a reliable energy storage solution but also offers potential
employment opportunities for those displaced by the green transition, and a new lease on life
for decommissioned coal power plants.

The research focuses on the critical flaws of Li-ion batteries, the economic instability caused
by the green initiative, and the efficient use of resources. While there are several alternatives
to Li-ion batteries, none have shown significant promise for future applications. This paper
explores the application of conventional energy storage systems enhanced with new
technologies, including binary cycles, electromagnetism, and thermodynamics. The proposed
thermal energy storage system is presented as a feasible and practical solution for current
energy storage challenges. The discussed system is designed to advance sustainability by
adhering to the principles of reduce, reuse, and recycle. One of the key components of this
system is the use of recycled steel, which not only promotes environmental sustainability but
also significantly reduces costs and enhances overall efficiency. By utilizing recycled
materials, the system minimizes waste and supports the circular economy.

This innovative approach offers a new lease on life for stalling coal power plants. Instead of
being decommissioned, these plants can be repurposed to operate in a different capacity,
leveraging their existing infrastructure. This repurposing requires minimal modifications,
allowing for the efficient use of large capital investments and land resources that would
otherwise go to waste. As a result, the transition to this new system can be achieved with

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relatively low investment compared to building new facilities from scratch. Furthermore, the
reactivation of coal power plants under this new system can generate significant employment
opportunities. By transforming these plants into hubs for sustainable energy storage, the
proposed system can create jobs in various sectors, including construction, maintenance, and
operations. This can help mitigate the economic impact of transitioning away from traditional
coal power, providing a stable source of income for many workers. The discussed system is
also designed to store large volumes of electric power efficiently. Unlike traditional coal
power plants, which produce dust and fumes, this new system operates cleanly, without
emitting harmful pollutants. This ensures a healthier environment for surrounding
communities and contributes to overall public health.

In summary, the discussed system not only addresses the need for sustainable energy storage
but also offers a practical solution for repurposing existing coal power plants. By promoting
the use of recycled materials, reducing costs, and creating employment opportunities, this
system supports both environmental and economic sustainability. Its ability to store large
volumes of electric power cleanly and efficiently makes it a promising alternative to current
energy storage solutions.

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CHAPTER 2
METHODOLOGY

2.1 Introduction
The data utilized for optimizing the parameters and conducting the research were
meticulously gathered from a variety of reputable sources. These sources include peer-
reviewed research papers, statistical data from trusted websites, and information provided by
government bodies. This comprehensive data collection ensures the reliability and accuracy of
the research findings. Once collected, the data were processed and optimized using Ansys
software, a powerful tool for engineering simulation. Ansys software was employed to
perform all necessary simulations, allowing for precise modeling and analysis of the proposed
system. This software's advanced capabilities enable the researchers to simulate real-world
conditions and optimize the system's parameters effectively. By leveraging data from diverse
and credible sources and utilizing sophisticated simulation tools like Ansys, the research
ensures a high level of accuracy and reliability in its findings. This rigorous approach not only
validates the proposed system's feasibility but also enhances the overall credibility of the
research.

2.2 Block Diagram

Fig. 2.2.1 Block Diagram

The block diagram of the proposed system illustrates its operational framework. During off-
peak hours, energy is drawn from the grid and used to heat a cubical structure via an inductive
heating coil, storing the energy as thermal energy. This stored energy is later retrieved using a
binary cycle. To enhance efficiency, the system incorporates three types of boilers operating
at temperatures of 1800°C, 1000°C, and 200°C. These boilers facilitate the conversion of
thermal energy back into electrical energy. The generated electricity is then supplied to the

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grid after meeting the necessary grid parameters.

2.3 Schematic Diagram

Fig. 2.3.1 Enclosure of Thermal Energy Storage System

Fig. 2.3.2 Geometry of thermal energy storage system

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Fig. 2.3.3 Cross-section of Thermal Energy Storage System

The discussed system features a cubical structure with dimensions of 3650 millimeters. This
cube is encased in a vacuum layer 500 millimeters thick, made of polyurethane, followed by
an additional vacuum layer of the same thickness. The cube itself is composed of a
combination of steel and graphite. The steel sections are cylindrical, each with a diameter and
length of 100 millimeters, and are spaced 50 millimeters apart. The gaps between the steel
sections are filled with graphite. Additionally, there is a 325-millimeter distance from the
cube's walls on both sides. The system's design is optimized for solar photovoltaics, ensuring
adequate lighting for 8 hours. The energy losses are minimized over a 24-hour period. The
cube's structure consists of 26,392,784 nodes and 70,594,499 elements. Simulations were
conducted using Ansys software, running 1,000,000 iterations at a pressure condition of 0.01
pascals to maintain the vacuum. The element size was set to 0.01 to achieve optimal results.
These simulations were carried out over a 24-hour period to ensure the system's reliability and
efficiency.

2.4 Equations

The system heated and steel sections are bringdown to its molten state for the energy
storage. The steel sections can be melted down at 1538 degree Celsius. The graphite
layer over the steel sections will prevent the flow of molten steel from its mold to
surroundings. The heat is given through induction heating. The depth of heating can be
find out by using eq(1)

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The power transferred to steel sections can be obtained by the eq(2)

The Heat Loss due to the Radiation is Described in eq(3)

The energy thus stored in the form of heat need to be retained for over a course of 24 hours. A
thick layer of 10 MM of vacuum is provided in between the outer wall and the cube. The
vacuum will insulate the cube with the outside world resulting longer retentivity of the heat
with minimum loss. The only heat loss is due to the radiation which can accounted as
following.

The Effectiveness of Heat Exchanger is Found in eq(4)

The net Power Output of the Plant is Explained in eq(5)

Once the structure is energized and stored via vacuum insulation, The energy will get
discharged as needed to deliver the power requirement during the off-peak hours when
there is no or least supply and demand is high. The discharging is done by using binary
cycle. The binary cycle uses the mercury as the working fluid to retrieve the heat
energy to convert the energy into electricity.
2.5 Finite Element Analysis

Finite Element Analysis (FEA) is a numerical technique used to simulate physical

phenomena, allowing engineers to reduce the necessity to create physical prototypes. FEA
software works by breaking down a real object into a large number of finite elements in the
forms of shapes like cubes or tetrahedrons. Mathematical equations help predict the behavior
of each element, and a computer then adds up or averages all the individual behaviors to
predict the behavior of the actual object. FEA is a powerful tool for mechanical product
design, but it also requires careful documentation and reporting to ensure accuracy, validity,
and reproducibility. An FEA report should include several plots showing the finite element
mesh, input data and settings, output data, and key findings. FEA is commonly used in
mechanical, aerospace, automotive, and civil engineering projects as well as biomechanics.

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CHAPTER 3
SIMULATION AND RESULTS

3.1 INTRODUCTION
All the simulations have been done in Ansys software. The system is heated towards 1538
degree Celsius. The radiation from the cubical structure over a course of 24 hours is noted.
The temperature retentivity over a time period of 24 hours is noted. Pressure loss in the cabin
which is made vacuum is also noted. The temperature of internal, enclosure, also the vacuum
space is also noted. The obtained results are given below.

Fig. 3.1.1 Temperature contour of the inner cube, the temperature thus simulated is 1800
Kelvin.

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Figure 3.1.1 shows the simulated result shows the state of the cube after the heating process is
done. The cube is heated up to the melting point of the steel ie: 1811 K.

Fig. 3.1.2 Temperature contour of the outside cubical structure, the simulated temperature is
573 Kelvin.

Figure 3.1.2 shows the simulated result shows the temperature outside the temperature the
structure after the two-stage insulation of vacuum and poly urethane.

Figure 3.1.3 Thermal Radiation from The Cubical Structure

Figure 3.1.3 shows the radiation coming out from the cubical structure after the heating is
done. The radiation coming out is not uniform and it resembles the iron pellets placed in it.

Figure 3.1.4 Pressure Characteristics Over Position

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From the Figure 3.1.4, the obtained result is there is no increase in pressure over the positions.
The pressure is uniform everywhere which ensures the complete vacuum over the
intermediate system which ensures the minimal loss of heat due to radiation and also no heat
transfer rather than radiation.

Figure 3.1.5 Temperature vs Position

From the figure 3.1.5, temperature vs position will give how the cube is getting energized
with the inductive coil. The heat is distributed uniformly all over the cube over the dimension
of 3650 milli meter.

Figure 3.1.6 Wall Temperature vs Position

From the figure 3.1.6, wall temperature vs position which gives the result of temperature
retentivity over a course of 24 hour. There is a drop in temperature in the corners due to
radiative losses. The radiative losses are more prone to corner or the sharp edges.

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CHAPTER 5
CONCLUSION

The proposed system can be an alternative for the energy storage in the grid application as an
alternative to the Li-ion batteries which are in the market as of current standard. The proposed
system could hold the temperature and heat energy stored for over 24 hours without much
losses and could deliver maximum output or the heat from the cube to the binary cycle system
and then to the steam cycle system where which the energy is extracted. As the system
proposed to practice in a coal power plant with in built setups such as boiler, cooling tower,
turbine, generator and connection to the grid, the proposed system will give an employment to
the people who are working in this field and for people who are losing their job in this field
due to the green concept.

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REFERENCES

[1] Fernandes, Nereus. (2018). Induction Heating - Theory and Applications [1], The theory
and application of induction heating.
[2] O. Lucía, P. Maussion, E. J. Dede and J. M. Burdío, "Induction Heating Technology and
Its Applications: Past Developments, Current Technology, and Future Challenges," in
IEEE Transactions on Industrial Electronics, vol. 61, no. 5, pp. 2509-2520, May 2014, doi:
10.1109/TIE.2013.2281162.
[3] Fokin, L.R., Popov, V.N. & Naurzakov, S.P. Equation of state and thermodynamic
properties of saturated and superheated mercury vapors up to 1650 K and 125 MPa. High
Temp 49, 832–840 (2011). https://doi.org/10.1134/S0018151X11050075
[4] Sarbu, I, Dorca, A. Review on heat transfer analysis in thermal energy storage using latent
heat storage systems and phase change materials. Int J Energy Res. 2019; 43: 29– 64.
https://doi.org/10.1002/er.4196
[5] Patel, Ketul M, An Overview of Applications of Induction Heating (2019). International
Journal of Electrical Engineering and Technology, 10(2), 2019, pp. 81-85, Available at
SSRN: https://ssrn.com/abstract=3536945
[6] Hengyun Zhang, Faxing Che, Tingyu Lin, Wensheng Zhao,3 - Thermal modeling,
analysis, and design,Editor(s): Hengyun Zhang, Faxing Che, Tingyu Lin, Wensheng Zhao,
In Woodhead Publishing Series in Electronic and Optical Materials, Modeling, Analysis,
Design, and Tests for Electronics Packaging beyond Moore, Woodhead Publishing, 2020,
Pages 59-129, ISBN 9780081025321, https://doi.org/10.1016/B978-0-08-102532-
1.00003-2.
[7] Bavane, Vikas & Rindhe, Pooja. (2017). Energy Analysis of Thermal Power Plant.
[8] Akhmetov, B. & Georgiev, Aleksandar & Kaltayev, Aidarkhan & Dzhomartov, A &
Popov, Rumen & Tungatarova, Madina. (2016). Thermal energy storage systems – review.
Bulgarian Chemical Communications. 48. 31-40.
[9] Al-Taha, Wadhah & Osman, Hassan. (2018). Performance Analysis of a Steam Power
Plant: A Case Study. MATEC Web of Conferences. 225. 05023.
10.1051/matecconf/201822505023
[10] Gang Li, Xuefei Zheng,Thermal energy storage system integration forms for a sustainable
future,

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