Esprit Rock



Chandkheda, Ahmedabad

Project Report
Under subject of
B.E. Semester 6
(Mechanical branch)

Submitted by:
Sr no. Name of student Enrollment No.
1 Gohel Smit K. 150050119023
2 Patel Adarsh P. 150050119057
3 Patel Deep Rameshbhai 150050119061
4 Patel Deep Rohitbhai 150050119062

Faculty guide :
Prof. .Mehul shah
Head of Department :
Prof. Ramesh Mewada
Academic year :



This is to certify that the project report entitled Wave Energy Converter is prepared
and presented by Gohel Smith, Patel Adarsh, Patel Deep Rameshbhai and Patel
Deep Rohitbhai bearing Enrollment No. 150050119023, 150050119057,150050119061
and 150050119062 of 3rd Year of B.E (Mechanical Engineering) and their work is

Prof. Mehul Shah Prof. Ramesh Mewada
Guide Name Head of Department

Babaria Institute of Technology
Department of Mechanical Engineering
At: Varnama, Ta: Vadodara, Dist.: Vadodara, Pin: 391240



We all have taken efforts in this project. However, it would not have been possible
without the kind support and help of many individuals and organizations. We would like
to extend my sincere thanks to all of them. We are highly indebted to Faculty member
Prof. Mehul Shah for their guidance and constant supervision as well as for providing
necessary information regarding the project & also for their support in completing the
project. We would like to express our gratitude towards our lab faculty & member of
Bits mechanical faculty team for their kind co-operation and encouragement which help
us in completion of this project.


Contents: Title
1. Introduction 5
2. Literature Review 6
3. AEIOU Canvas 9
4. MIND Mapping 11
5. EMPATHY Canvas 12
6. IDEATION Canvas 13
7. PDC Canvas 17
8. LNM Canvas 18
9. Design and Calculation 19
10. Conclusion 24
11. Future Scope 24


1.0 Introduction:
Under the guidance of Assistant Professor Mehul Shah, we students of Babaria Institute
of Technology pursuing Mechanical Engineering are presenting our project “Wave
Energy Converter” in design Engineering.

1.1 Project Introduction:
The purpose of our project is to produce and provide electricity through natural
resources (waves).The WEC is a new, highly efficient technology that harnesses the
immense, renewable energy contained in ocean waves. It can extract and convert energy
from both the rising and falling of waves.

1.2 About Team Members:
Smit Gohel : 150050119023
Patel Adarsh : 150050119057
Patel Deep Rameshbhai : 150050119061
Patel Deep Rohitbhai : 150050119062


2.0 Literature review

1C J Cargo*, A R Plummer, A J Hillis, and M Schlotter Centre for Power
Transmission and Motion Control, University of Bath, Bath, UK The manuscript was
received on 10 December 2010 and was accepted after revision for publication on 31
March 2011.
Wave energy has the potential to be a major provider of renewable energy, especially in
the UK. However, there is the major problem of producing efficient devices for a wide
variety of sites with different operating conditions. This article addresses the time
domain modelling of a heaving point absorber connected to a hydraulic power take-off
(PTO) unit in regular waves. Two cases for the hydraulic PTO unit are considered: an
ideal model and a model containing losses. Component losses are included to give a
more accurate prediction of the maximum power production and to discover if the
parameters to optimize the device change when losses are included. The findings show
that both cases are optimized by varying the size of the hydraulic motor and the optimal
size is only dependent on wave period and the trend is the same for both cases. Results
also showed that to maximize the power produced for both cases, there is an optimal
force that the unit produces, which can be derived from theory. Finally, power reduction
as a result of the hydraulic losses is also observed with efficiencies reducing at larger
wave heights.
This study has described a time domain analysis of a floating buoy, oscillating in heave
with a hydraulic PTO unit in regular monochromatic waves. It is fully understood that
monochromatic sea waves do not occur in reality but it is useful to fully comprehend the
operation of these complex WEC devices in regular waves before they can be
investigated under more realistic conditions. It has been shown that a typical hydraulic
PTO unit behaves similar to a Coulomb damper producing a square wave force rather
than the sinusoidal nature of a viscous damper as previously assumed. The hydraulic
PTO unit was modelled as both an ideal unit and a unit including losses so that a realistic
power output and PTO unit efficiency could be predicted. The PTO unit efficiency was
found to only vary slightly with wave height. It has been shown that a hydraulic PTO
unit can be optimized, in the same manner as a viscous damper, by altering the motor
displacement, which varies the effective damping of the unit. The optimum damping of
the PTO unit has a linear relationship to wave period but only a minimal variation with
wave height. The inclusion of losses in the model has no effect on the optimum values
for the effective damping of the PTO unit. The optimum value is not the same as that of
a viscous damper. However, all three cases investigated showed a similar trend for the
optimum PTO force amplitude against wave period. This implies that for a given wave
period, regardless of PTO design, there is an optimum force amplitude which the PTO


unit should produce to maximize the power generated.Hence, the next stage of study will
be to investigate a force control strategy and develop a control algorithm to optimize the
device in varying sea conditions. Furthermore, it will be necessary to investigate the
response of the device in irregular waves and determine whether similar optimum
conditions and trends exist.

2 B Drew , A R Plummer and M N sahinkaya, department of mechanical engineering,
university of bath ,bath UK
Ocean waves are a huge, largely untapped energy resource and the potential for
extracting energy from waves is considerable. Research in this area I driven by the need
to meet renewable energy targets, but is relatively immature compare to other renewable
energy technology.

The potential for generating electricity from wave energy is considerable. The ocean is
huge resource, and harnessing the energy in ocean wave represents an important step
towards meeting renewable energy targets. This review introduces the current status of
WEC technology. The different device types are established and evaluated the institution
and companies involve in WEC development as well as collaborative wave energy
project are also identified.

3 Liguo Wang, Jens Engström, MalinGöteman, and Jan Isberg, Journal of Renewable
and Sustainable Energy
This paper investigates a method for optimal control of a point absorbing wave
energy converter by considering the constraints on motions and forces in the time
domain. The problem is converted to an optimization problem with the cost function
being convex quadratic and the constraints being nonlinear. The influence of the
constraints on the converter is studied, and the results are compared with uncontrolled
cases and established theoretical bounds. Since this method is based on the knowledge
of the future sea state or the excitation force, the influence of the prediction horizon is
indicated. The resulting performance of the wave energy converter under different
regular waves shows that this method leads to a substantial increase in conversion
A time-domain analysis has been presented to evaluate the performance of a point
absorber WEC whose motion is governed by a control algorithm. The WEC is
oscillating in regular waves. By considering constraints of motion and forces, a
convergent numerical scheme was implemented to solve the power maximization
problem. It indicates that constraints can influence the performance of the converter:
with suitable constraints, less losses, and more absorption power can be achieved. In the
method, future knowledge of the excitation force is assumed within a relatively short


finite time interval (the prediction horizon).It was found that, although no phase control
has been directly attempted, in theory this control method can attain a phase shift
between excitation force and velocity of buoy, which means the excitation force is in
phase with the velocity, and this performance is similar to the performance from latching
control. High relative capture width, more than 90% in some regular waves, can be
achieved by this method.

4silviabozzi, adria Moreno miquelalessandroantonimi , Giuseppe passoni and

In this paper, they investigate the feasibility of wave electricity production in Italian
seas by the development of the Sea based wave energy converter (WEC). A numerical
model of the coupled buoy-generator system is presented, which simulates the behaviour
of the wave energy converter under regular waves of different wave heights and periods.
The hydrodynamic forces, including excitation force, radiation impedance and
hydrostatic force, are calculated by linear potential wave theory, and an analytical model
is used for the linear generator. Two buoys of different radii are considered to explore
the effect of buoy dimension on energy conversion and device efficiency. The power
output is maximized by adding a submerged object to the floating buoy, in order to bring
the system into resonance with the typical wave frequencies of the sites. The simulation
results show a very good agreement with the published data on the Sea based WEC. The
model is used to estimate energy production at eight Italian offshore locations. The
results indicate that the degree of utilization of the device is higher than 20% at the two
most energetic Italian sites (Alghero and Mazara del Vallo) and that it can be
considerably increased if the floating body is connected to a submerged object, thanks to
the resonant behaviour of the WEC. In this case, the degree of utilization of the device
would be higher than 40% at most of the study sites, with the highest value at
MazaradelVallo. The work enlarges the perspective, to be confirmed by experimental
tests and more accurate numerical modeling, on clean electric power production from
ocean waves in the Italian seas. In this case, the degree of utilization of the device would
be higher than 40% at most of the study sites, with the highest value at MazaradelVallo.
The work enlarges the perspective, to be confirmed by experimental tests and more
accurate numerical modeling, on clean electric power production from ocean waves in
the Italian seas.

5 Ye Li1and Yi-Hsiang YuNational Wind Technology Center National Renewable
Energy Laboratory (NREL) Golden, CO, 80401, USA

During the past few decades, wave energy has received significant attention for
harnessing ocean energy. Industry has proposed many topologies such as an oscillating
water column, a point absorber, an overtopping system, and a bottom-hinged system. In
particular, many researchers have focused on modeling the floating-point absorber,
which is thought to be the most cost-efficient technology to extract wave energy. To
model such devices, several modeling methods have been used such as the analytical


method, the boundary-integral equation method, the Navier-Stokes equations method,
and the empirical method. To assist the development of wave energy conversion (WEC)
technologies, this report extensively reviews the methods for modeling the floating-point

They have summarized the existing numerical methods for simulating a floating-point
absorber resulting in the review of existing analytical methods including, Morison
Equation methods, boundary BIEM, and NSEM. Here, we provide further insights into
these methods.
In terms of cost-effectiveness, selecting a method for simulating floating-point absorber
WEC devices involves determining the capability of the method to describe the physics
of flow.The features of each hydrodynamic modeling method. Depending on the purpose
of the study, each method has its advantages. The analytical method and MEM only can
be used for simple geometries while BIEM and NSEM can be used for studying a more
complicated geometry. If one intends to conduct an optimization or real time analysis,
the analytical method, the MEM, and the frequency domain BIEM have often been used.
Note that the frequency domain BIEM is generally used for calculating the
hydrodynamic coefficients of the excitation force, and these coefficients need to be
carefully determined and adjusted near resonance. Time domain BIEM can be used for
optimization, but the computational cost remains too high for the purpose of real time
analysis, particularly for 3D simulations. Since NSEM requires longer computational
time, it is used only for detailed analyses, particularly when wave breaking and
overtopping and viscous damping effects are significant.


3.0 AEIOU Canvas

User :
It includes workers, common people, Dealers, Manufacturer, Designer, Industry.
Environment :
Environments include the entire arena where activities take place. It is the character and
function of the space overall, of each individual’s spaces, and of shared spaces.
Cool wind blowing and water surrounded are included here.
Interactions :
Interactions are between a person and someone or something else; they are the building
blocks of activities. It is special interactions between people, objects in their
With our interaction with A general manager of ESSAR steel, we came to know that our
product’s maintenance was a tough task.
Objects :
It includes Buoy, Rope, Stator, Piston, Spring.
Activity :
Topic analysis, Creating Prototype, Designing, Manufacturing, Fabrication , Problem
analysis, Testing.


Fig:-1. AEIOU Canvas


Mind Mapping Canvas

Fig:-2. Mind Mapping


4.0 Empathy Mapping Canvas
This exercise allows us to better analyze the desires and needs of clients, and in the
process uncover previously unseen or unnoticed ways to improve a product or service.
It’s a very simplistic way to identify and reduce potential hurdles and in the process, we
are better able to please our clients.
We use four building blocks when preparing an empathy map canvas, namely:
In this stage, we find the various users which are directly or indirectly related to our
project.We include different industries,comman man, farmer, industries. Industries are
included in the user as they frequently utilize electricity for different purposes.
Stakeholders mean a person or organisation with an interest.
In this stage, we find the user who will directly or indirectly related to user. It includes
Designer, Dealer, workers,Manufacturer.
They are involved during different stages of product development.
Activities :
Activities are directly or indirectly related to Stakeholders.
It includes Problem analysis, Creating Prototype, Designing, Manufacturing,
Advertising Testing.
Story Boarding :
There was a village named Radhanpur, located at sea-shore. The village was far away
from urban area and was suffering from lack of electricity. Then some Engineers took
review of the place and they developed wave energy converter,which produces
electricity from motion of the waves, which was not costly.And the problem of the
village people get solved and they were happy.


There was an industry located exactly on the sea-shore. They were making use of
electricity produced from fossil fuels, which was costly as well as harmful to
environment. A worker working in that industry thought and he implemented wave
energy converter with the help of engineers working there and the owner, and he was
successful. He was awarded with great increment from his owner and he was happy.
Near a village named Nabipur, a large amount of electricity was produced by thermal
power plant, which usually make use of fossil fuels. This thermal power plant releases
toxic gases in the atmosphere and makes it pollute. So the village people and farmers
were suffering from health problem and crop failure. And this serious problem made
villagers sad.
There was a village named Hastinapur located at sea-shore. This village was far away
from the urban area and there was serious problem of electricity availabilities .The
farmers of the village were struggling without electricity and they were sad.
From the above canvas, we can come across the problems faced by the clients using the
current technology. And how our product will be useful to them.


Fig:-3. Empathy Mapping Canvas


5.0 Ideation canvas
An ideation canvas is a rough whiteboard where ideas can be stretched into any limits or
dimensions. The ideation canvas sheet includes:
People :
It includes workers, common people, Dealers, Manufacturer, Designer, Industries.
Activities :
Technical activities such as Designing, manufacturing, fabrication, Assembly, creating
prototype are included here.
Situation /context /Location :
This part of ideation canvas sheet consists of the part which describes the situation,
reference and the location of the problem occurring and the product or service to be
Here any situation taking place related to our project can be included such as use of
electicity for residential purpose, farming,commercial purposes. Context includes supply
of electricity and location includes farm, villages and industries.
In anvillage nearby the sea-shore electricity produced by WEC was supplied. So here
supply of electricity becomes the context while village becomes the location.
Props/possible solution :
It includes the components used in the product. So, Piston , stator , spring , support
,buoy , rope etc are included here.
From the ideation canvas, we are not able to find solutions to the defined problem but
can define the best possible problem and stretch out its possible scope.And from the
situation/context/location we can come across where our product is used, and for what


Fig: – 4. Ideation Canvas


6.0 Product Development Canvas
Produce and supply the electricity.
It includes comman people, manufacturer, designer, dealers .
Product experience:
1) Simple to construct
2) Low efficiency
3) Health friendly.
Product functions:
1) Provides power
2) Supplies electricity
Product Features:
1) No noise pollution
2) Reduces shoreline erosion
3) Makes use of renewable energy
4) No releases of toxic gases.
1) Buoy
2) Rope
3) Stator
4) Piston
5) Spring.
Customer Revalidation:
From the feedback received from the customer, we would make changes in the was “Good Product” and environment friendly.
The efficiency of the product is less and costly.
Reject, Redesign, Retain:


During the verification with the customer, we verified the design of the product,
durability, and efficiency.

The feedback obtained was:
1) The efficiency of the product is less and costly.
So, we have to redesign the product overcoming with better efficiency.
Redesign: Improvement in the design of the product and materials used.
By this canvas we can know that what are the actual barriers faced by the users and a
way to find the solution to it.

Fig:- 5. Product Development Canvas


7.0 Learning needs matrix

Fig-6 Learning needs matrix


8.0 Design and calculation

Fig:-7. Buoy
The buoy of spherical in shape with diameter 6.32 cm is taken.It is connected to the
generator through modern synthetic rope. Its weight is around 60 gm. A buoy
connected a stiff rope will drive the generator piston as the wave is rising.

Fig:- 8. Stator

Stator is with outer diameter of 2.5 cm. The height is fixed to 11 cm. The two phase coil
winding on the outer surface around 2500 turns.



Strong permanent magnets as per the optimum need is used. Four pieces are taken with
diameter 2.4cm.

Fig:- 9. Magnet

Piston moves up down with the motion of the buoy .Its diameter is slightly lesser than
the stator so that it can move freely. Magnets are attached to the piston and hence its
weight is around 300gms.


Where, E=e.m.f induced in Armature,
Ø=Flux/Pole (Weber).
N=no of rpm,
A= 2(Wave winding),
Z=no of conductors,
P=no of Pole
Here , Ø = 1/4 (From Neutral position to 2 inch for left side and 2 inch right side)
Z= 1
N= 20 rpm
P = 1
R= 6 K ? ( Internal Resistance of Galvanometer )
= 6 * 103 ?.



;#55349;;#56376;=0.04166 V

According to Ohm’s Law ,V= IR
0.04166 =I * 6 * 103
I= 6.943 * 10-6 A
I= 6.94 µA


9.0 Conclusion
By seeing all the aspects of the project, we can conclude that this is a reliable project as
it uses renewable energy resource and also is environment friendly. It can be very much
useful at the places nearby the sea-shore. Also it does not releases any toxic gases in the

10.0 Future Scope
Nowadays 80% of the electricity is being produced using coal, and fossil fuels which are
getting depleated, as they are non renewable source of energy.Also the toxic gases
releases by them are harmful to us and pollutes the environment.So there is a need of
production of electricity from renewable resources as much as possible without causing
harm to anyone.So, the requirement of this can be fulfilled by our project.Hence, there is
a wide scope of our project in coming years.


or_efficient_wave_energy_absorption_by_floating_devices accessed Oct 09

Research papers:

1) Henderson R. design simulation, and testing of a novel hydraulic power take-off
2) Vladimir I. Vissarionov Department
3) Robin pelc, rod M fujita environmental defence
4) C J Cargo*, A R Plummer, A J Hillis, and M Schlotter Centre for Power
Transmission and Motion Control
5) B Drew , A R Plummer and M N sahinkaya, department of mechanical