ELEC3105: Electrical Energy
Assignment: T2, 2020
Total marks: 35
Information sheet:
This assignment will contribute 13% toward your final marks. The last day of submitting the
assignment is 5 pm, Tuesday, 11 August (Week 11) via Assignment link in the Moodle. The
assignment must be uploaded to the Moodle system as a pdf file. Late submission will not be
permitted under any circumstances; submission via email attachment will also not be considered
once the deadline expires.
Since this assignment counts towards your formal assessment for this subject, you are required to
sign a declaration and attach this cover sheet to the front of your submission. Without this signed
declaration, the assignment will not be considered for assessment. A fillable pdf file for signed
declaration is included with the other documents.
Note that plagiarism (i.e. copying of assignment or pay someone to do your assignment) is an
academic offence. If suspected of plagiarism, you may be referred to disciplinary board and will be
subjected to heavy penalties. Check https://student.unsw.edu.au/plagiarism for detailed
information.

What is being assessed by this assignment?
The purpose of this assignment is to assess the following learning outcomes and graduate
attributes:
Learning outcome:
• Be capable of selecting, and designing some important power engineering devices for real-
life applications,
• Be able to apply underlying theories and concepts in the design process.
Graduate attributes:
1. Analytical skills, critical thinking and creative problem solving.
2. Demonstration of the understanding of principles.
3. Effective use and communication of relevant information.












Feedback Rubric/marking criteria:
The marks related to each part of the question are shown next to it. Percentage distribution of the total mark of each part is
according to the 4 marking criteria given in the table. This table will also serve as the feedback rubric once you have received
your score.
Score <50% 50-64% 65-74% 75-84% 85-100%
Criteria
Application of under
lying theories and
concepts.
40%

Student does not
have grasp of
information;
student cannot
answer questions
about subject.
Student
demonstrates sound
knowledge by
giving expected
answers to most,
but not all
questions.
Student
demonstrates
good
knowledge by
giving
expected
answers to all
questions, but
fails to
elaborate.
Student
demonstrates
full knowledge
by answering
all questions
with
explanations
and
elaboration.
Student
demonstrates full
knowledge (more
than required) by
answering all
questions with
explanations and
elaboration.
Interpreting findings
from solving the
problems and plots.
30%
Student does not
interpret the
findings/reach a
conclusion.
Student provides an
inadequate
interpretation of the
findings and does
not derive a logical
solution to the
problem.
Student
provides an
adequate
interpretation
of the findings
and solves
some of the
problem, but
not all.
Student
provides an
adequate
interpretation
of the findings
and solves the
problem, but
fails to provide
alternatives.
Student provides
a logical
interpretation of
the findings and
clearly solves the
problem, offering
alternative
solutions.

Identifies and
assesses
assumptions,
conclusions,
implications and
consequences.

20%
Fails to identify
conclusions,
implications, and
consequences of
the issue or the key
relationships
between the other
elements of the
problem, such as
context,
implications,
assumptions, or
data and evidence.
Identifies some of
the conclusions,
implications, and
consequences of
the issue or the key
relationships
between the other
elements of the
problem, such as
context,
implications,
assumptions, or
data and evidence.
Identifies and
discusses some
of the
conclusions,
implications,
and
consequences
considering
context,
assumptions,
data, and
evidence.
Identifies and
discusses
conclusions,
implications,
and
consequences
considering
context,
assumptions,
data, and
evidence.
Identifies and
discusses
conclusions,
implications, and
consequences
considering
context,
assumptions, data,
and evidence.
Objectively
reflects upon their
own assertions.
Neat and clear
presentation of data
and information.

10%
Illegible and
unclear
presentation and
information.
Somewhat clear
and neat
presentation.
Clear and neat
presentation of
data but with
room for
improvement.
Clear and neat
presentation of
data.
Data and
information are
presented with
professional
clarity and
neatness.

Total Marks: 35
Tasks:
You are a lead engineer at a reputed energy consultancy firm. Your firm has won a contract to
investigate ‘deployment of rooftop solar (photovoltaic) and wind energy for a large building at UNSW
Kensington campus’. The firm’s management has given you the task of fact-finding. You are required
to produce a short technical report for the management based on your findings. The report must find
answers/solutions to the following questions/problems:
Question 1: Solar Energy [10 marks]
(i) [2 marks] Find a building with the most suitable rooftop area. Estimate the available roof area for
installing the photovoltaic panel. You can use the software tool Nearmap.com to assess the
building rooftops.
(How to access Nearmap.com – Go to UNSW Library website> search for Nearmap. In the search
result, select Nearmap under database category. Once you click the link, it will ask you to register
as a UNSW user. You will receive an instruction email to activate your UNSW account).
(ii) [1 marks] Find the average power and energy consumption for the building of your choice from
(i). You can use the link below to check energy consumption and average power of a building at
UNSW Kensington campus :
https://www.sustainability.unsw.edu.au/our-plan/energy-and-water-efficiency/kensington-
campus-live-energy-consumption
(iii) [3 marks] A datasheet of a commercial photovoltaic module was provided in the pdf file:
(Origin1500_Panel_Specifications.pdf). Use this data to estimate how many panels you will
require to supply the average power of (ii)? Can you fit all the panels on the available roof area
found in (i)? If not, what is the power that can be provided by fitting the maximum possible solar
panels in the available roof area?
(iv) [2 marks] How much annual energy saving is possible if the rooftop area is fully utilized using
the panels? To answer this question, you should consider the average irradiance and temperature
of the Kensington area and consult the panel specifications.
(v) [2 marks] How many panels need to be connected in series and parallel if the required output
voltage is 240V(DC) and power is the same as found in (ii).
Question 2: Wind Energy[25 marks]
In the discussion forum of ELEC 3105, many of you have concluded that a VAWT (Vertical Axis Wind
Turbine) can be used as an alternative to rooftop solar in the urban area. In this task, you will investigate
the feasibility of VAWTs for the UNSW Kensington campus.
(i) [2 marks] Use an internet search to find the average wind speed and air density for the Kensington
campus. Then calculate the power density (W/m3) of the area.
(ii) [6 marks] A VAWT turbine is used with a 3-phase, 4-pole, Y-connected, 300V (line), 50Hz.
Induction Generator for wind energy conversion. Equivalent circuit parameters of the generator
were found from experimental tests:
R1= 1. 54Ω/ph, R2= 3 Ω/ph, X1=X2=5 Ω/ph and Xm = 58 Ω/ph. Constant rotational losses were
200W.
There is a mechanism of slip control for the generator. The slip can be varied from
0 to -0.45 in steps. Find the output power of the generator for the step variation of slip. Present the
result as a plot between output power versus generator speed in rpm.
(iii) [4 marks] Calculate the range of efficiency for the generator for the same slip variation of (iii).
Plot the efficiency versus slip for the generator.
(iv) [2 marks] Using the efficiency versus slip plot of (iii), find the slip and the generator speed at
which the maximum efficiency occurs. These values will be considered as the rated slip and speed
of the generator.
(v) [2 marks] Record the value of the maximum efficiency and the output power at this efficiency.
These values will be considered as the rated power and efficiency of the generator.
(vi) [2 marks] Data of the VAWT turbine is provided in a pdf file (Vertical Axis Wind Turbine
Specifications_assignment2020.pdf). If the generator speed and slip are fixed at their rated
values, find the required gear ratio for cut-in-wind speed, cut-out-wind speed, rated-wind-speed
and average wind speed of UNSW Kensington campus.
(vii) [2 marks] Is the rooftop area that you have chosen for Question 1 also suitable to install VAWTs?
If not, you may look for other suitable buildings using Nearmap. Once a building is identified,
find the average power using the same link as in Question 1 (ii).
(viii) [5 marks] Considering the rated output power of the induction generator from (v), estimate how
many VAWTs will be required to supply the average power for the chosen building. Is it feasible?
Why or why not? How many VAWTs can be practically installed on the rooftop of the building?
How much annual energy saving is possible using these installations? Is it comparable to the
energy saving of Q1(iv)? Make comments.


End of the assignment