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i
Hybrid Alternative Energy Solutions for the
University of Guyana Turkeyen Campus
KEVON CAMPBELL
Submitted in partial fulfillment of the requirement for Bachelor of
Engineering
(Electrical Engineering)
Electrical Engineering
Faculty of Technology
University of Guyana
August 25th, 2014
i
DECLARATION
I declare that this thesis entitled “Hybrid Alternative Energy Solutions for the
University of Guyana Turkeyen Campus” is the result of my own research except
as cited in the references. The thesis has not been accepted for any degree and is
not submitted in candidature of any other degree.
Signature :…………………………….
Author : KEVON CAMPBELL
Date : 25th
August 2014
ii
DEDICATION
I would like to specially dedicate this paper
to my loving Mother, Sister, Brother, Father
and God-Siblings.
iii
ACKNOWLEDGEMENT
The researcher would firstly, like to thank God, the all Sufficient One, for health, strength and
guidance to complete this project.
Special thanks to project supervisor Ms. Verlyn Klass, for her willingness to work with and offer
assistance when needed to see this project completed. Her invaluable input was greatly
appreciated throughout the process. To Mr. Gary Munroe, a longtime friend and former
employer, thank you, our discussions helped to overcome hurdles whenever they were
encountered.
To my family and close friends your support and encouragement meant a great deal especially
when difficulties were encountered. Whether it was a call, text or a cup of tea, your efforts to
assist during the process of completing this report will forever be remembered.
A special thank you to members of staff from the Registrar’s office, Deputy Vice-Chancellor’s
Office and Bursary who facilitated the researcher to acquire the necessary information to aid in
the completion of this report.
iv
ABSTRACT
The University of Guyana like all other consumers on the National electricity grid receives a
monthly utility bill from the Guyana Power & Light Inc (GPL). At present, this figure is
approximately GY $ 7 Million. With an annual rise in consumption and addition of new loads by
the University, a rise in this figure will undoubtedly be seen. Amidst growing electricity
demands, the university needs to tap into more economical and beneficial mediums for its
electricity supply while exploring electricity conservation mechanisms.
The project sought to assess and evaluate the University’s electricity needs, with the view of
substituting alternative energy sources; examine methods which can be utilized to reduce the
University’s electricity consumption and the development of an alternative energy
implementation guide. A system will be developed consisting of various alternative energy
sources, to cater for these energy needs and mechanisms will be explored to reduce the
University’s consumption.
Exploring these avenues will allow the University to be in a position to supplement its energy
needs, with the prospect of supplying energy to the National Grid in the event of minimal
demand. This will also allow the University to become a leader in local alternative energy
research, development and implementation.
v
Table of Contents DECLARATION .......................................................................................................................................... i
DEDICATION ............................................................................................................................................ ii
ACKNOWLEDGEMENT ............................................................................................................................ iii
ABSTRACT .............................................................................................................................................. iv
LIST OF FIGURES ....................................................................................................................................viii
LIST OF TABLES ......................................................................................................................................viii
LIST OF ABBREVIATIONS ......................................................................................................................... ix
LIST OF APPENDICES ............................................................................................................................... ix
Chapter One: Introduction....................................................................................................................... 1
1.1 Chapter Introduction: .................................................................................................................... 1
1.2 Introduction ................................................................................................................................... 1
1.3 Background .................................................................................................................................... 1
1.4 Statement of Problem: ................................................................................................................... 2
Chapter Two: Literature Review .............................................................................................................. 3
2.1 Chapter Introduction: .................................................................................................................... 3
2.2 A Snapshot of Guyana’s Electricity Sector: .................................................................................. 3
2.3University of Guyana Electricity Consumption and Demand: ....................................................... 3
2.4 Alternative Energy: .................................................................................................................... 4
2.5 Sources of Alternative Energy: ................................................................................................... 5
2.6 Bio-Energy: ................................................................................................................................ 6
2.7 Solar Energy (Photovoltaic): ....................................................................................................... 7
2.8 Solar Energy (Concentrated Solar): ............................................................................................. 7
2.9 Wind Energy: ............................................................................................................................. 8
2.10 Geothermal Energy: ................................................................................................................. 9
2.11 Hydropower: .......................................................................................................................... 10
2.12 Clean Coal: ............................................................................................................................. 11
2.13 Hydrogen Fuel Cells: ............................................................................................................... 11
2.14 The Future of Alternative Energy: ........................................................................................... 12
2.15 Implementing Alternative Energy Systems: ............................................................................ 12
2.16 Basic Components of an Alternative Energy System: .............................................................. 12
2.17 Electricity Conservation: ......................................................................................................... 14
vi
Chapter 3: Methodology........................................................................................................................ 16
3.1 Chapter Introduction ................................................................................................................... 16
3.2 Objective One: ......................................................................................................................... 16
3.3 Objective Two: ......................................................................................................................... 16
3.4 Objective Three:....................................................................................................................... 16
Chapter 4: Results and Analysis ............................................................................................................. 17
4.1 Chapter Introduction ................................................................................................................... 17
4.2 Objective One .............................................................................................................................. 17
4.2.1 Analysis of Feasible Alternative Energy Sources: ............................................................. 17
4.2.2 Determination of Monthly Campus Demand and Consumption ...................................... 18
4.2.3 Proposed Alternative Energy Systems: ............................................................................ 21
4.2.3.1 Single Source Systems: ................................................................................................... 21
4.2.3.1.1 Solar Energy: .............................................................................................................. 21
4.2.3.1.1.1 A Comparative Analysis: .......................................................................................... 21
4.2.3.1.1.2 Campus Photovoltaic System Sizing: ....................................................................... 25
4.2.3.1.1.3 Designed Campus PV System Specifications ............................................................ 28
4.2.3.1.1.4 Designed Campus PV System Land Requirements: .................................................. 29
4.2.3.1.1.5 Designed Campus PV System Mounting Requirements: .......................................... 31
4.2.3.1.1.6 Designed Campus PV System Angle of Tilt ............................................................... 32
4.2.3.1.1.7 Designed Campus PV Balance-Of-System Components: .......................................... 34
4.2.3.1.1.8 Designed Campus PV System Material Costing ........................................................ 36
4.2.3.1.2 Wind Energy: .............................................................................................................. 37
4.2.3.1.2.1 Wind Data: ............................................................................................................. 37
4.2.3.1.2.1.1 Logic Energy Windtracker: ..................................................................................... 37
4.2.3.1.2.1.2 Interpreting the Logic Energy data: ........................................................................ 37
4.2.3.1.2.1.3 The Hobo Micro Station: ........................................................................................ 39
4.2.3.1.2.1.4 Interpreting the Hobo Micro Station data: ............................................................. 39
4.2.3.1.2.2 Estimated Output Utilizing Wind Data: .................................................................... 40
4.2.3.1.2.3 Feasibility of Utilizing Wind Energy for Campus Power ............................................ 41
4.2.3.1.3 Bio-Energy: ................................................................................................................. 43
4.2.3.1.3.1 Potential Bio-Energy Avenues: ................................................................................ 43
4.2.3.1.3.1.1 Rice Husk: .............................................................................................................. 43
vii
4.2.3.1.3.1.2 Bio-energy: ............................................................................................................ 45
4.3 Objective Two ........................................................................................................................ 45
4.3.1 Current Campus Consumption: ....................................................................................... 45
4.3.2 Suggested Consumption Reduction Measures: ............................................................... 45
4.4 Objective Three ...................................................................................................................... 47
4.4.1 Solar Power Implementing Guide ................................................................................... 47
4.4.2 Wind Energy Implementing Guide .................................................................................. 49
Chapter Five: Recommendations & Conclusion ................................................................................ 51
5.1 Chapter Introduction: ............................................................................................................. 51
5.2 Objective One: ....................................................................................................................... 51
5.2.1 Solar Energy: .................................................................................................................. 51
5.2.2 Wind Energy: .................................................................................................................. 51
5.2.3 Bio-energy: ..................................................................................................................... 51
5.2.4 Concluding Remarks: ...................................................................................................... 51
5.3 Objective Two: ....................................................................................................................... 52
5.4 Objective Three: ..................................................................................................................... 52
Bibliography .......................................................................................................................................... 53
End Notes .............................................................................................................................................. 55
viii
LIST OF FIGURES Figure 1: Global Energy Consumption ...................................................................................................... 5
Figure 2: Components of an Alternative Energy System ......................................................................... 14
Figure 3: Worldwide annual direct normal irradiation in kWh/m2/y ....................................................... 24
Figure 4: Resulting map of the annual sum of direct normal irradiation for potential CSP sites .............. 24
Figure 5: University of Guyana Aerial View ............................................................................................ 29
Figure 6: Proposed Site for the Designed Campus PV System ................................................................. 30
Figure 7: Sun Position and Direction ...................................................................................................... 32
Figure 8: Site Coordinates ...................................................................................................................... 33
Figure 9: Adjustable Angle Calculation ................................................................................................... 33
Figure 10: PV System with Balance-of-System Components Shaded ...................................................... 34
Figure 11: Logic Energy Windtracker illustration of Campus Wind Data using a Histogram ..................... 37
Figure 12: Logic Energy Windtracker illustration of Campus Wind Data using Wind Rose Intensity......... 38
Figure 13: Typical Wind Turbine Power Curve ........................................................................................ 40
LIST OF TABLES Table 1: Sources of Alternative Energy ..................................................................................................... 5
Table 2: Bio-energy Technologies4 ........................................................................................................... 6
Table 3: Photovoltaic Technology [14] ..................................................................................................... 7
Table 4: Categories of Concentrated Solar Plants [15] .............................................................................. 8
Table 5: Categories of Wind Turbines ...................................................................................................... 9
Table 6: Types of Hydropower Systems ................................................................................................. 10
Table 7: Viability Table........................................................................................................................... 18
Table 8: Consumption Data ................................................................................................................... 19
Table 9: Initial Demand Determination .................................................................................................. 20
Table 10: Combined Estimated Demand ................................................................................................ 20
Table 11: Solar Energy Merit Comparison .............................................................................................. 23
Table 12: Energy Potential ..................................................................................................................... 41
ix
LIST OF ABBREVIATIONS
UG University of Guyana
GPL Guyana Power and Light Inc
GEA Guyana Energy Agency
LCDS Low Carbon Development Strategy
kW Kilo-Watt
kWh kilo-Watt hrs
CIT Centre for Information Technology
CBJ Cheddi B. Jagan Lecture Theatre
IAST Institute of Applied Science and Technology
LIST OF APPENDICES
Request for Information 56
Letter of Response 57
GE 700 kW Solar Inverter Fact Sheet 58-59
Schneider Electric Xantrex Charge Controller Data Sheet 60-61
1
Chapter One: Introduction
1.1 Chapter Introduction:
This chapter gives the reader a holistic overview of the project. After review of this chapter, the
reader will be poised to conceptualize the foundation elements of this paper.
1.2 Introduction
Alternative energy generation, although still thought to be an emerging technology, has
transformed the manner in which electricity is generated. Through the utilization of this
technology, one can reduce their carbon footprint, which is seen as being beneficial and
environmentally friendly. Although the initial implementation of alternative energy is seen as
costly, overtime, such systems pay for themselves and a price tag can’t be placed on the
environmental benefits [1] afforded by such systems.
1.3 Background
The issue of the University’s electricity consumption and resulting high utility bill can be
discussed from two perspectives:
Firstly, from the viewpoint of the University being self sufficient, relying solely on its own
generated electricity supply.
Globally, as State or Government funding is reduced, Universities are forced to increase tuition
fees as a stop-gap measure to recoup the shortfall in funds [2]. The University of Guyana
receives an annual subvention from the Government of Guyana (GoG). Despite this injection of
funds the University has recorded a deficit for a few years. Only last year, an approximate debt
of GY $ 482 Million Dollars was incurred which saw the University being unable to pay for
services rendered by various organizations, among which was GPL [3] [4].
With that said it becomes evident that the University needs to become a self sustaining entity and
this can be achieved in part by addressing its electricity consumption.
Secondly, from the viewpoint of the University being used as a pioneer for the local green
energy initiative and implementation strategy [5].
Guyana has long been and currently is pursuing a myriad of localized awareness and green
energy campaigns, namely the Low Carbon Development Strategy (LCDS), the Guyana Energy
2
Agency (GEA) 8KW Grid-Tie Photovoltaic System, among others [5]. These initiatives are
geared at gaining an understanding of our local alternative energy capabilities, as well as raising
public awareness about alternative energy.
Implementing an alternative energy system at the University will allow the institution to become
a local pioneer in this sector. This would spark further interest in the field, as well present
opportunities for local research and study.
Essentially, combining the two perspectives highlights the importance of such a system and the
benefits with which its establishment can offer.
1.4 Statement of Problem:
On the global scale, the concept of green energy is constantly being perpetuated to the masses.
The driving force behind this ideological change is the holistic aim of reducing man’s
dependency on coal and oil for electricity generation. This is due to the fact that coal and oil
generation release greenhouse gases which pollute the environment. It should also be noted that
the cost of oil continues to fluctuate, to the point where in some cases it becomes unpredictable.
Presently, the UG has an approximate monthly electricity bill of GY $7 Million. This figure is a
reflection of the University’s consumption and utility’s implemented tariff. However, the harsh
reality is that this figure will undoubtedly increase unless smart energy decisions are made and
implemented. These decisions will lead to a reduction and possible elimination of this figure.
As the leading tertiary institution, the UG should be spearheading the local energy conservation
initiative. In an energy utopia, the University would be energy efficient; supplying its own power
to meet its consumption needs and when these needs are minimal, power could be supplied to the
National Electricity Grid.
Holistically, such an initiative would see the University being able to invest these savings in
other areas, resulting in institutional development. It would also undoubtedly lead to local
research in the field of alternative energy, which could be spearheaded by the University.
3
Chapter Two: Literature Review
2.1 Chapter Introduction:
This section seeks to highlight literature examined throughout the duration of the project. Its
intent is to allow the reader to gain vital insight into the thought process utilized by the
researcher to develop the project outcomes.
2.2 A Snapshot of Guyana’s Electricity Sector:
In any electricity sector, power generation plays an integral role in ensuring consumer demand is
met, and presently this is the responsibility of GPL. From a historical stand point, Guyana’s
electricity sector saw staggered growth, which resulted in the country’s populace being faced
with prolonged power outages [6]. During this period of staggered growth electricity was
generated from bagasse, fuelwood and petroleum products.
The sector saw a turnaround through an Operation & Maintenance partnership with Wartsila [7],
Government investment and development, and international funding. This has moved the
electricity sector to its current position, one which sees the installation of new and the upgrading
of existing Substations, the implementation of a Supervisor Control and Data Acquisition
(SCADA) network, among others. At present, most of the electricity generated is produced from
Heavy Fuel Oils, Crude and Diesel; although a small percentage is produced from co-generation.
However, it should be noted that the electricity grid is more reliant on generation from fossil fuel
sources [8].
With an installed capacity of 156.9 MW and total availability of 125.7 MW to meet a total peak
demand of 104.8 MW [8], it becomes apparent that GPL is heavily reliant on its fossil fuel
generation. This heavy reliance on fossil fuel can pose challenges should the cost of fuel rise to a
point, where consumer tariffs being to increase. Currently, the company essentially absorbs fuel
cost fluctuations [9], thereby negating the need for tariff adjustment. However, it is envisioned
that these practices can’t be sustained unless changes are made or new sources of electricity
generation are utilized.
2.3University of Guyana Electricity Consumption and Demand:
By definition demand [10] refers to the “ratio of the maximum demand of a building to the total
connected load”. It can more or less be attributed to the amount of energy consumed at any
given time, and is expressed is Kilo-Watts. Similarly consumption [10] speaks of “the electrical
energy used over or consumed over time”. It is expressed in Kilo-Watt Hours (KWH).
4
The University’s consumption1 for the period Aug, 2011 to May, 2012 was approximately
797412 KWh. When examined this figure postulates to a hefty annual payment to GPL. Like any
growing institution, it is envisioned that the University’s consumption will increase, resulting in
an increased utility bill. It should however, be mentioned that further research is needed to draw
concrete conclusions about the University’s electricity consumption and demand.
2.4 Alternative Energy:
The issues of climate change and global warming are said to be the greatest threats to civilization
and the environment. Caused by the release of green house gases e.g. carbon dioxide (CO2)
resulting from mankind’s daily activities. These activities range from the burning of fossil fuel
for electricity generation to emissions from automobiles. Climate change and global warming are
linked to the melting of the polar ice caps and glaciers, a rise in sea level, humidity and oceanic
temperature, altering of weather patterns, among others [11] [12].
According to oxforddictionaries.com renewable energy2 refers to “energy from a source that is
not depleted when used such as sunlight, wind, rain, tides, etc”. Similarly, alternative energy3
refers to “energy fueled in ways that do not use up the earth’s natural resources or otherwise
harm the environment”. The two concepts in essence go hand in hand, and are often called “free”
energy sources. With the continued depletion of fossil fuel sources, it has been predicted that by
2050 a third of the world’s energy will be produced from alternative sources [12].
It is as a result of carbon emissions and the need for continuous use as opposed to one time use,
that global concern has been raised. Consequently, initiatives have been launched at the local
level with the hope of reducing carbon emissions on a global scale. In Guyana, one such
initiative is the Low Carbon Development Strategy (LCDS) [5]. That said, at the local level this
has led to the birthing of alternative technologies and ideas which will essentially aid in the
global effort to combat climate change dioxide [12].
It must be underscored that although initial implementation costs for such systems are
considerable, technological advancement has seen them being more efficient and economical
when compared to years past.
Despite the fact that local initiatives are in motion, more needs to be done with regard to data
collection, research and public awareness in the arena of alternative energy.
1 See Kevon Grimmond’s “ENERGY AUDIT OF TECHNOLOGY BUILDINGS” (ELE401 – 2010/2011) 2 See http://www.oxforddictionaries.com/definition/english/renewable-energy 3 See http://www.oxforddictionaries.com/definition/english/alternative-energy?q=alternative+energy
5
2.5 Sources of Alternative Energy:
Based on the definitions mentioned earlier a clear view of alternative energy sources becomes
clear. These sources are considered to be anything that doesn’t leave a carbon foot print, but
instead can be reused since they are naturally occurring. Some of which are [13]:
- Bio-energy
- Wind Energy
- Clean Coal
- Solar Energy (Photovoltaic)
- Geothermal Energy
- Hydrogen fuel cells
- Solar Energy
(Concentrated Solar)
- Hydroelectricity
Table 1: Sources of Alternative Energy
Figure 1: Global Energy Consumption
From a global perspective alternative sources are already playing an integral role in the
generation of electricity. An examination of the above image, illustrates that these sources are
slowly making a difference in the way electricity is generated.
6
2.6 Bio-Energy4:
Said to be the product of biomass and biofuel, bio-energy4 is referred to as energy from organic
matter. This organic matter can either be plant or animal based [13]. This form of alternative
energy has actually been used for many years, however sustainable properties are only now
being realized.
However, its sustainability is likened to a double-edged sword. On one hand, the CO2 produced
by bio-energy is similar to that of fossil fuel. On the other hand, the fast growing plants such as
food crops, trees, grassy and woody plants remove CO2 from the atmosphere. Hence, in order for
bio-energy to be truly sustainable a balance must exist, resulting in zero net CO2 emissions. It is
therefore vital that this cycle continues.
Some bio-energy technologies [14] used to produce electricity are:
Direct-fired systems:
These systems burn feedstock to produce
steam which is harnessed by turbines to
generate electricity
Anaerobic Digestion:
This technique utilizes bacteria to decompose
organic matter in an oxygen deprived
environment. This results in the production of
methane, which is burned to produce
electricity.
Co-firing:
This process combines fossil fuel and bio-
energy feed stock in high efficiency boilers to
generate electricity.
Pyrolsis:
This occurs when biomass is heated in the
absence of oxygen producing pyrolsis oil. This
oil is burned like petroleum to produce
electricity.
Gasification:
Such systems consist of an oxygen deprived
environment fed by high temperatures to
convert biomass in to gas. This gas consisting
of Hydrogen, carbon monoxide and methane,
is in turn fed to a gas turbine which produces
electricity.
Small Modular systems:
This is the terminology used to classify bio-
energy systems that produce 5MW or less of
electricity.
Table 2: Bio-energy Technologies4
Mention must be made of local efforts with regard to the production of bio-ethanol. A
demonstration plant was established in 2013 at the Albion Sugar Estate [5]. The plant can
produce 1000 litres of bio-ethanol daily. Locally the technology still has to be advanced,
however based on international studies5, bio-ethanol can be utilized to produce electricity
through combustion, and this indicates the potential for local bio-ethanol.
4 See http://www.renewableenergyworld.com/rea/tech/bioenergy/biopower 5 See http://www.thegreenage.co.uk/tech/bioethanol-electricity/
7
2.7 Solar Energy (Photovoltaic):
This refers to energy released from the sun, namely in the form of light and heat. It is considered
to be the cleanest and most inexhaustible energy source known to mankind [15]. First observed
by French Scientist Becquerel in 1839, Photovoltaic cells or panels convert the sun’s energy into
direct current. This occurs when the energy makes contact with the panel’s surface material,
causing the electrons to become free. Once free the electrons flow in a specific direction owing
to the presence of an electric field. It is this flow of electrons that produces the direct current.
Owing to the rapid growth of the photovoltaic industry in recent years6, a variety of methods are
available for obtaining the sun’s energy. This has been achieved through advances in materials
used to make the PV panels, as well as the panel technology.
Technology Efficiency Use
Thermal non concentrating
45% - 75% Heating systems
Thermal Solar Pond (Saltwater) 10%
Uses an Organic Rankine
Cycle turbine or Stirling
engine to produce electricity
without steam
Photovoltaic
Crystalline Silicon wafer
18% - 23% Electricity generation
Thin film silicon
12% Electricity generation
Thin film non-silicon
16% - 20% Electricity generation
Table 3: Photovoltaic Technology [14]
2.8 Solar Energy (Concentrated Solar):
Concentrated Solar (CS) [14] refers to the use of mirrors or lenses to focus the sun’s rays and
heat to produce electricity via steam turbine connected to a generator. CS Plants are being
established around the world with a typical 250 MW station costing US $600 Million. Despite
the benefits, technological development is seen as the driving force behind these plants,
especially in the area of heat storage. This essentially allows CSP’s to generate electricity after
sunset and on cloudy days. This is achieved through the utilization of liquids with a high thermal
capacity. Concentrated Solar Plants consist of four categories:
6 See http://www.energytrendsinsider.com/wp-content/uploads/2013/10/insert-3.png?00cfb7
8
Category Description Efficiency
Parabolic Trough
Consisting of a series of polished parabolic reflectors,
either mirrors or metals. These reflectors focus the
sun’s energy onto an absorption tube, containing a
high thermal capacity liquid (usually oil), which runs
along the focal point of the reflector. The heated fluid
drives a steam turbine.
25%
Linear Fresnel
Reflector
Consisting of long, thin segments of flat mirrors to
focus the sun’s energy onto a fixed absorber located
at a focal point common to all the reflectors. The
absorber can contain multiple heat transfer tubes,
usually containing water, which drives a steam
turbine.
20%
Dish Stirling
Consisting of dish parabolas that focus light onto a
single point. At the focal point, a stirling engine is
positioned, which converts the heat to mechanical
energy. Using a Dynamo, the mechanical energy is
converted to electricity. Unlike the previous
categories, the Dish Stirling utilizes dual axis to
follow the sun.
31.25%
Solar Power Tower
Consisting of ground mirrors which track the sun’s
position and focus its energy onto a collector, fixed
atop a tower. The collector contains tubes with the
high capacity liquid, usually molten salt. This
transfers the heat to water which drives a steam
turbine.
25%
Table 4: Categories of Concentrated Solar Plants [15]
Since Guyana falls within the “sun belt”, the country has untapped solar generation capabilities.
2.9 Wind Energy:
Wind is a resultant of the earth’s rotation, its irregular surface and heating from the sun. In
ancient times wind energy was utilized to drive water pumps and to grind grain. Utilizing these
ancient principles has seen the development of the modern wind turbine [15]. Wind energy is
considered to be the fastest growing energy technology in existence, partly due to improvements
in cost and efficiency. Wind turbines have an average life span of 20 to 25 years, thus making
investment worthwhile.
9
Wind energy is generated when wind moves over the turbine blades, usually two or three
depending on the configuration, and a lift is generated. The blades are attached to a shaft and the
lift caused the blades to rotate, resulting in the shafts rotation. The rotating shaft drives a
magnetic field in a generator, which results in the production of electricity.
Categories of Wind
Turbines Description Efficiency
On-Shore Horizontal Axis
Wind Turbine (HAWT)
The axis of the horizontal axis wind turbine is
parallel to the wind stream and ground. The main
rotor shaft and electrical generator are at the top of
the tower and must be pointed in the direction of
the wind stream. A gearbox is used to translate the
slow blade motion into a faster motion to drive the
generator.
0 – 40%
Off-Shore Horizontal Axis
Wind Turbine (HAWT)
These turbines take advantage of strong oceanic
wind patterns and utilize a large area. Since off-
shore wind is more consistent the output from such
wind farms is maximized.
40%
Vertical Axis Wind Turbine
(VAWT)
When compared to HAWT’s, VAWT’s have a
lower start up wind speed and can be positioned
closer to the ground. Unlike HAWT’s, VAWT’s
can be placed in closer proximity to each other
therefore increasing the overall efficiency of the
installation.
40%
Concentrated Wind
Seen as an improvement to the HAWT, the
Concentrated Wind utilizes a cone to focus wind
towards its blades. This causes the wind’s velocity
to increase as it passes over the blades of the
turbine. This results in an improved efficiency.
56 - 90%
Blade Tip Power Systems
(BTPS)
Designed to operate at low speeds, with rotating
blades that carry magnets. Electricity is generated
when these magnets pass through coils housed in
the perimeter ring. Its design allows for reduced
resistance and easy maintenance. BTPS is
designed by WindTronics and made by
Honeywell.
0 – 56%
Table 5: Categories of Wind Turbines
2.10 Geothermal Energy:
This type of energy is produced by utilizing steam and hot water trapped below the earth’s
surface [13]. In order to reach these reservoirs one must drill between 500 – 2000 meters. After
drilling the steam is forced to the surface in a controlled manner to drive steam turbines, thus
producing electricity. Geothermal energy can be essentially harnessed from any part of the
worldi.
10
Methods of Geothermal Energy Generation7:
- Dry Steam: Steam of 150oC or greater is used to drive steam generators.
- Flash Steam: Steam occurring at 180oC or greater is fed to a low pressure separator,
resulting in the production of flash steam, which is then fed to a steam
generator.
- Binary Cycle: Low temperature water (usually 57oC) is used to feed a second liquid with
lower boiling point. The interaction of the two liquids produces steam,
which is fed to a steam generator.
2.11 Hydropower:
This refers to electricity produced from the action of falling water. The water’s force causes
turbine blades to turn and a connecting shaft transfers this rotation to a generator. The shafts
rotation causes a magnetic field to develop within the generator, producing electricity [13]. It is
estimated that 20% [15] of the world’s electricity is produced from hydropower, illustrating its
reliability. Hydro systems provide demand flexibility, during periods of high demand water
intake can be increased to meet the increased demand, and likewise, intake can be reduced
during periods of minimal demand.
Types of hydro systems:
Type of Hydro System Description Efficiency
Dammed Reservoir
Water is limited and impounded behind a dam
structure. Using an intake system, the water is fed
through a penstock to turbines which are
connected via a shaft to a generator.
80 – 95%
Run- of-River
This type of installation is an alternative to
“damming” a waterway. Instead, a portion of the
water is diverted to the generator, while the
remainder is allowed to flow naturally. It should be
noted that for such an installation to be efficient, a
constant flow rate is required.
80 – 95%
Micro(<100KW) &
Pico(<5KW) Hydro
A penstock pipe diverts water from the river to the
turbine generator and it is then channeled
downstream back to the river. Either the dammed
or run-of-river method can be employed. Such
installations are considered ideal for small
communities.
50-85%
Table 6: Types of Hydropower Systems
7 See http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/how-geothermal-energy-
works.html#Energy_Capture
11
Based on studies and assessments8 conducted of locations countrywide, Guyan has an estimated
hydropower generation capacity of 7600MW.
2.12 Clean Coal:
Electricity generation from coal satisfies the power needs of many developed countries.
Globally, coal generation is said to be the largest contributor of generated electricityii. However
coal generation releases tremendous amounts of pollutants9, some of which are SO2, NOx,
particulates and mercury, into the atmosphere. Clean coal technologies have however been
developed to reduce these emissions, particularly due to concerns about global warming and
climate change. Consequently, power plants built today are said to release approximately 90%
less pollutants [16].
Some clean coal technologies are:
- Liquidized-Bed Combustion: During combustion limestone and dolomite are added to
coal to reduce sulfur dioxide formation.
- Integrated Gasification Combined Cycle: The coal is converted to a gas or liquid via
heat and pressure. After refining, the coal can be utilized.
- Electrostatic Precipitators: These devices charge particles in the plume stack and
collection plates remove them, thus reducing the content of the emissions.
Essentially, clean coal generation employs a variety of technologies to maximize emission
reduction.
2.13 Hydrogen Fuel Cells:
A fuel cell is similar to a battery, however it doesn’t require charging. It electrochemically
converts chemical energy into DC electricity, heat and water, provided that fuel is supplied [17].
An electrolyte solution separates an anode and cathode. Hydrogen is passed to the anode while
oxygen is passed to the cathode. The hydrogen reacts with the electrolyte ion, producing water
and electrons. These electrons travel along wires and are a representation of the current
generated by the cell. A continuous cycle is formed, where water and electricity are created.
Advantages of fuel cell use are:
8 See http://www.gea.gov.gy/energy-development/hydropower 9 See http://www.ucsusa.org/clean_energy/coalvswind/c02c.html
12
- High Efficiency - Simplicity - Quietness
- Low emissions - No moving Parts
2.14 The Future of Alternative Energy:
The future of alternative is extremely promising. With advances in technology alternative energy
systems will see output maximization and the reduction of implementing costs [15]. Essentially,
a cap or limit cannot be placed on the future of alternative energy since its benefits are
exceptional.
In Guyana, we have only scratched the surface of our green energy potential. In order to make
sufficient strides in this arena, more local research is required as well as capital investment and
incentives.
2.15 Implementing Alternative Energy Systems:
Alternative energy systems are implemented utilizing two schemes [18]. These are:
Off-Grid: This relates to a system that is independent of a utility company. The system
produces and stores its own power and utilizes a stand-by generator should a short fall in
generation occur. For such systems to be effective proper load analysis and adequate storage
provisions must be made. Off-Grid systems are ideal for remote areas where utility supply is
absent and they are designed to be self sufficient. However, batteries and generators require
periodical maintenance to preserve their longevity.
Grid-Tie: Similar to the off-grid scheme, except, the utility company replaces the backup
generator. During periods of excess generation where demand is low, excess power is fed
back to the grid and the opposite happens when a short fall occurs and demand is high.
Special energy meters are utilized to monitor such systems. Grid-Tie systems also remove the
need to have a battery bank and backup generator; however a power outage will highlight
this need.
2.16 Basic Components of an Alternative Energy System10
:
Charge Controller: Utilized to prevent batteries from over charging, by diverting
excess power to a “diversion load”.
10 See http://www.absak.com/library/home-power-system-diagram
13
Diversion load: Consumers excess power to prevent damage to batteries. The diversion
load, usually a large resistor, must be designed to handle maximum power output from the
power source.
Battery Bank: Used to store electricity until it is needed. Deep cycle batteries are
preferred since they can be charged and discharged for years.
Energy Meter: This monitors the system and can indicate how much power is being
produced and consumed, the battery condition, system voltage and amperage flow. Modern
meters allow for PC based interfacing.
Breaker Box: Whether it is DC or AC, the breaker box allows for safe transfer of
electricity to the load.
Inverter: An inverter converts DC to AC to allow household loads/appliances to be
connected to the system.
Generator: This is backup measure should any aspect of the system fail.
14
Figure 2: Components of an Alternative Energy System
2.17 Electricity Conservation:
Electricity conservation, by definition11
, relates to the reduction of energy consumed during a
process or by a system, through the elimination of wastage and rational use. In a nutshell it refers
utilizing electricity in a manner that would equate to prolonged use and saving. It is also
concerned with avoiding wastage of non renewable energy sources such as fossil fuel and heavy
fuel oil. Energy conservation goes hand in hand with energy efficiency, which refers to utilizing
less energy to carry out the same process or taskiii
.
The global shift in the direction of renewable energy has emphasized and propelled the need for
energy conservation and efficiency. It is thus evident that the University’s annual consumption,
as at Aug 2011 to May 2012, of 797412 kWh can be attributed to some amount of inefficiency
and wastage. However, to quantify this detailed energy study of the campus will have to be
11 See http://www.businessdictionary.com/definition/energy-conservation.html
15
conducted. This project however, will only examine and suggest areas where conservation
methods can be applied, namely:
- Smart metering
- Lighting
- Air conditioning
- Office Equipment
16
Chapter 3: Methodology
3.1 Chapter Introduction
This chapter explains and highlights the methods and approaches used to undertake the
objectives of this project. These objectives will be implemented in four stages, namely research,
design, implementation and testing/debugging. The researcher thought it best to elaborate on
each objective and its corresponding implementing stages so as to give a clear and holistic view
of the project.
3.2 Objective One: “Examine energy alternatives such as Hydro, Wind, Solar and Biofuel
for campus wide power”
Research will encompass appropriate literature such as sources of alternative energy, energy
modeling and predictive software, UG’s monthly electricity consumption and utility bill,
alternative energy systems, to name some. With an understanding of the relevant literature, an
alternative energy system will be designed. Of the sources examined, in the research phase12
,
only those deemed feasible will be utilized in the system design. The design will consider the
University’s current and estimated future demand. A software model will be used to implement
and test the designed system. Should any issues arise; the designed system will be adjusted.
3.3 Objective Two: “Explore the utilization of energy saving technologies to reduce the
overall campus monthly electricity consumption”
Research will be carried out to gain an understanding of energy conservation technologies and
methods used to implement these technologies. From the research, those technologies which are
applicable to the University will be utilized to outline an energy conservation scheme(s). These
scheme(s) will be implemented and tested against real world scenarios.
3.4 Objective Three: “Develop a model which would serve as a basic guide for implementing
Alternative Energy”
Research will be undertaken into implementing the feasible sources of alternative energy
indicated under objective one. With knowledge gained an implemention guide will be developed.
The developed guide will take practical and realistic scenarios into consideration.
12 See “Sources of Alternative Energy” in the Literature Review Section
17
Chapter 4: Results and Analysis
4.1 Chapter Introduction
This Chapter seeks to quantify the project’s objectives and expound on their results. Its aim is to
give the reader insight into the thought processes used by the researcher to achieve the project
objectives.
4.2 Objective One
4.2.1 Analysis of Feasible Alternative Energy Sources:
The table below examines the viability of the alternative energy sources, mentioned in the
literature review portion of this document. Those sources deemed feasible will be used to
develop the alternative energy system(s). This system will be designed to cater for campus
demand among other factors.
Energy Source Feasibility Reason
Geothermal Energy No
Guyana doesn’t fall within the known geothermal
region (or ring of fire). However, exploration by
means of drilling can determine, definitively
whether any geothermal energy can be harnessed
in Guyanaiv.
Hydro-Electricity No
No falling water exists around or near the
University campus. However, a number of
locations with hydro potential have been
identified, with development they can be utilized
for addition to the national grid.
Clean Coal No
Coal exploration hasn’t been conducted in
Guyana. However, peat deposits have been
discovered and its viability is currently being
examinedv.
Hydrogen Fuel Cells Maybe
Can be utilized to replace to conventional lead
acid battery, thus making the developed
power system more stable.
Large cells act as power generators and only a
constant fuel source is required to generate
electricity. Fuels such as methanol, ethanol,
LPG and hydrogen are currently being utilized
internationally.
Wind Energy Yes
The University lies on Guyana’s coastline and is
therefore exposed to considerable wind
conditions. It can therefore be postulated that
wind power can be harnessed to supply power to
18
the University’s electricity network.
Solar Energy (PV) Yes
Owing to the fact that Guyana is within the “Sun
Belt”, the harnessing of solar energy becomes
plausible.
Photovoltaic systems are being implemented
in various locations country wide.
Concentrated Solar Plants have not been
implemented in Guyana; however an
assessment of its potential will be done.
Solar Energy (Concentrated) Yes
Bio-Energy Maybe
The fuel sources (plant or animal based) needed
to produce bio-energy are not native to the
University’s campus and would therefore have to
be transported (e.g. Rice Husk) to be utilized in
any bio-energy based system. This would see an
added cost to the operation of such a system.
It is worth mentioning that plasma gasifier
technology has been improved to allow
everyday garbage to be utilized to produce
electricity. For on campus use, an assessment
of the daily garbage generated must be done
prior to the establishment of such a system.
It should also be noted that bio-energy
systems require some amount of safeguards to
ensure optimum output is achieved. For
instance, when using rice husk, its moisture
content must carefully be controlled to ensure
it can be utilized effectively. Table 7: Viability Table
4.2.2 Determination of Monthly Campus Demand and Consumption
The University of Guyana’s electricity network consists of several load centres which are
metered to allow for billing from GPL. The meters used are of the energy and demand type. Both
record kWh, however the demand meter also allows for kW readings to be measured over preset
intervals. The load centers used to obtain a general representation of the campus demand and
consumption are Centre for Information Technology (CIT), Cheddi B. Jagan Lecture Theatre
(CBJ), General Campus and Bursary, Personnel and Admin. All of these centres use the demand
type meter except CBJ. In order to develop this representation, utility bills of these load centers
were examined. This proved to be the best and less labor intensive method owing to fact that
time wouldn’t permit the installation of the University’s sole power analyzer at these centers for
prolonged periods.
19
Location Meter
Number Year Description
Consumption Total
Aug Sept Oct Nov Dec Jan Feb March April May June July
CIT IT
0001059
2011 Max Demand (kW) 44.1 47.44 56.14 43.03 46.84 47.35 52.07 47.84 59.56 67.72 58.81 39.12 610.02
Consumption(kWh) 6074.4 6360 6450 6460 5214 5114.48 7575.6 7408.88 9240 7844 6507.6 4724.4 78973.36
2012 Max Demand (kW)
51.8 39.62 55.68 51.56 60.35 55.57 48.29 362.87
Consumption(kWh) 3566.4 3922.8 6408 7183.2 7401.6 4934 4651.2 38067.2
2013 Max Demand (kW) 48.23 47.17
95.4
Consumption(kWh) 3562.8 4958.4 8521.2
CBJ
2011
Consumption(kWh)
1141 1577 1920 2145 2204 1695 2167 2267 2047 1346 1409 19918
2012 1968 1934 2461 2244 2252 2281 1690 14830
2013 1530 1530
General
Campus
IT
0001437
2012 Max Demand (kW)
317.64 325.32 366.72 367.92 361.88 356.4 312.72 2408.6
Consumption(kWh) 59400 75636 80460 89364 88740 90264 71808 555672
2013 Max Demand (kW) 274.68 320.28
594.96
Consumption(kWh) 50544 74195 124739
Bursary, Personnel
& Admin
IT
0002134
2012 Max Demand (kW) 57.04 66.13 67.09 63.38 65.84
319.48
Consumption(kWh) 10612.8 11240 12622.4 11552 8616 54643.2
2013 Max Demand (kW)
49.33 57.5
106.83
Consumption(kWh) 6723.2 9588.4 16311.6
Table 8: Consumption Data
20
Using max demand readings from the General Campus, CIT and Bursary, Personnel and Admin
load centers, an initial demand determination of the campus load was made.
Year
Load Center
CIT General Campus Personnel, Bursary &
Admin
2011 67.72
2012 60.35 367.92 67.09
2013 48.23 320.28 57.5 Table 9: Initial Demand Determination
Owing to the fact that CBJ is metered by an energy type meter, an estimation of its demand was
made. It must, however be noted that this method will only yield an average demand value for a
particular period. To compensate for this, a percentage of the estimated demand value found and
used to make up the combined estimated demand.
Year CBJ Consumption
Data (August) Average Demand Combined Estimate
2011 2267 kWh 2267
(31 × 24)= 3.047 3.047 × 1.50 = 4.5705 ≅ 4.6
2012 2461 kWh 2461
(31 × 24)= 3.307 3.307 × 1.50 = 4.9605 ≅ 5
2013 1530 kWh 1530
(31 × 24)= 2.056 2.056 × 1.50 = 3.084 ≅ 3.1
Table 10: Combined Estimated Demand
Summing the initial demand and combined estimated demand allows for the campus demand to
be realized.
𝐶𝑎𝑚𝑝𝑢𝑠 𝐷𝑒𝑚𝑎𝑛𝑑 = (5 + 67.72 + 367.92 + 67.09) × 1.05
𝐶𝑎𝑚𝑝𝑢𝑠 𝐷𝑒𝑚𝑎𝑛𝑑 = 507.73 × 1.05
𝐶𝑎𝑚𝑝𝑢𝑠 𝐷𝑒𝑚𝑎𝑛𝑑 = 533.1165 𝑘𝑊 ≅ 535 𝑘𝑊
Campus monthly consumption attributed to this demand is determined by summing the
corresponding consumption readings from the load centers under examination.
𝐶𝑎𝑚𝑝𝑢𝑠 𝐶𝑜𝑛𝑠𝑢𝑚𝑝𝑡𝑖𝑜𝑛 = (7844 + 89364 + 12622.4 + 2461) × 1.05
𝐶𝑎𝑚𝑝𝑢𝑠 𝐶𝑜𝑛𝑠𝑢𝑚𝑝𝑡𝑖𝑜𝑛 = 112291.4 × 1.05
𝐶𝑎𝑚𝑝𝑢𝑠 𝐶𝑜𝑛𝑠𝑢𝑚𝑝𝑡𝑖𝑜𝑛 = 117905.97𝑘𝑊 kWh
21
The figure 1.05 is used to factor in load growth into both demand and consumption
calculations owing to the fact only those utility bills made available where utilized. Load
growth is attributed to the installation of new AC units, security lights, among others.
4.2.3 Proposed Alternative Energy Systems:
As mentioned previously, alternative energy systems can be broadly categorized as either being
of the single source or hybrid type. Single source refers to an energy system that uses a single
renewable energy source, while the hybrid type combines two or more energy sources. With that
said, the researcher thought it best to design with both categories in mind. The proposed systems
are as follows:
Single Source Systems:
- Solar Energy
- Wind Power
- Bio-energy
Hybrid System:
- No hybrid systems will be examined.
4.2.3.1 Single Source Systems:
4.2.3.1.1 Solar Energy:
4.2.3.1.1.1 A Comparative Analysis:
Solar energy is categorized into Photovoltaic (PV) and Concentrated Solar (CS), and thus a
comparative analysis is required to determine which scheme is better suited to supply campus
power. Often Concentrated Solar and Photovoltaic technologies are said to be interchangeable,
however the analysis will examine the relative merits of each technology. Specific factors
required for optimum performance to be achieved will also be highlighted.
22
Merit Photovoltaic
‘Monocrystalline’
Concentrated Solar
‘Parabolic Through’
Light Required
Direct and Diffused Direct only
Solar energy technologies, as the name suggest, utilize the sun’s radiated
energy (sun light) to produce electricity. The amount of light allowed to fall
upon the absorption surface (panel or through) must be taken into
consideration. The amount of light is dependent upon a number of factors,
some of which are angle of tilt, shade from nearby trees or obstructions,
cloud coverage, among others. Most of these factors are controllable, except
cloud coverage.
- Research [19] by the US DOE National Renewable Energy Laboratory
(NREL) has shown that 1MW or less PV systems are rapidly affected by
the presence of cloud cover. It found that the overall power output can
increase or decrease owing to the fact that PV panels respond rapidly to
changes in the available light. These fluctuations are instantaneous and
translate to power output instability, which needs consideration. To
adequately compensate for low light-production electricity storage, in
the form a suitably sized battery bank, is required.
- It is said that [20] a Concentrated Solar Plant requires scant or limited
cloud cover for the installation to be efficient. Guyana doesn’t have a
recognized cloud cover index, that is, whether the cloud cover is low,
medium or high. However, according to Encyclopedia Britannica, it is
said to be high average. Although a CSP offers thermal storage for “sun
down” generation, the absorption liquid being utilized must be first
brought to and kept at the required temperature for steam production to
occur. With that said, it is envisioned that this temperature will fluctuate
owing to persistent cloud cover experienced. These fluctuations equate
to output instability. To compensate for this, the designed system can be
oversized such that at low light conditions a percentage of the rated
output can be delivered to the campus or auxiliary (Utility) power can be
switched-in to make up the short fall.
Land Use Negligible Considerable
Photovoltaic systems require a negligible amount of land area because they
are typically placed on existing structures. In contrast, solar-thermal
technologies may require a significant amount of land, depending upon the
specific solar-thermal technology used. Solar energy installations do not
usually damage the land they occupy, but they prevent it from being used
for other purposes. In addition, photovoltaic systems can negatively affect
wildlife habitat because of the amount of land area the technology requires.
Environmental
Impact
No direct impact unless panels are
broken, cracked or burnt in a fire.
- A Report compiled by Tetra
23
Tech Inc [21] found that
leaching from cracked or
broken PV panels poises a
minimal risk to humans and the
environment. It also found that
the accidental burning of panels
can release vapors and fumes
into the environment, which can
be harmful, however this
depends on proximity.
To fully comprehend the environmental impact of a solar energy installation
on campus, an Environmental Impact Assessment (EIA) is required. As
mandated by the Environmental Protection Agency (EPA), an EIA is
needed as ascertain whether such a project could potentially threaten the
environment of the people therein and what measures should be put in place
to prevent or minimize this occurrence.
Water Use
Minimal
- Water is occasionally used in
PV installations to wash dust
off panels.
Large
- Water is used primarily for
cooling of the absorption liquid
which produces steam to drive a
turbine, which produces
electricity.
- Similar to PV installations water
is utilized to removed dust from
the through, since dust reduces its
reflective capability. Dust
removal is however done more
frequent.
Life span 20-25 years 20 years
Storage
Capability Battery Bank Thermal Storage
Table 11: Solar Energy Merit Comparison
The comparative analysis highlights the unfavorable nature of CS in Guyana. On the basis of
Solar daily irradiance only, a PV installation on campus would be more sustainable as opposed to
a CS plant. As a result, the researcher opted to only focus on Photovoltaic design. The images
below highlight the daily irradiance and potential concentrated solar locals. As can be seen
Guyana does not fall within this category. This may change with improvements in the
technology, however, only time will tell.
24
Figure 3: Worldwide annual direct normal irradiation in kWh/m2/y
Figure 4: Resulting map of the annual sum of direct normal irradiation for potential CSP sites
Source:
http://www.dlr.de/tt/Portaldata/41/Resources/dokumente/institut/system/publications/Solar_Pace
s_Paper_Trieb_Final_Colour_corrected.pdf
25
4.2.3.1.1.2 Campus Photovoltaic System Sizing:
1. Determine system power requirements:
- Total Campus Consumption: 117,905.97 kWh
As highlighted previously, this value represents the maximum calculated consumption for a
given month. However, the kWh/day must be determined in order to adequately meet the daily
needs of the campus.
- Assumed daily kWh: (117905.97
31) = 3803.418 𝑘𝑊ℎ/𝑑𝑎𝑦
- Total PV Panel energy needed: 3803.418𝑘𝑊ℎ
𝑑𝑎𝑦× 1.3 = 4944.443
𝑘𝑊ℎ
𝑑𝑎𝑦
The 1.3 figure is an industry standard used to consider energy lost in the system
2. Sizing of the PV Panels:
- Finding the Panel Generation Factor:
This location specific figure is the product of lowest insolation value in (kWh/m2/day) and the
corrected Wp value. Owing to the fact that a panel’s Wp can decrease owing to a number of
factors (e.g. dirt), some adjustment or correction to this figure is needed. The considerations are
as follows:
15% for temperature above 25˚C
5% for sunlight not striking the panel directly
5% for dirt, grime and dust considerations
10% for panel aging
𝐶𝑜𝑟𝑟𝑒𝑐𝑡𝑒𝑑 𝑊𝑝 = 0.85 × 0.95 × 0.95 × 0.90 = 0.69
It should be noted that a 10% consideration for power losses due to panels not receiving power at
the maximum power point was neglected owing to the fact that an MPPT controller will be
utilized.
𝐿𝑜𝑤𝑒𝑠𝑡 𝐼𝑛𝑠𝑜𝑙𝑎𝑡𝑖𝑜𝑛 𝑉𝑎𝑙𝑢𝑒 = 5.04 kWh/m2/day
𝑃𝑎𝑛𝑒𝑙 𝐺𝑒𝑛𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝐹𝑎𝑐𝑡𝑜𝑟, 𝑃𝐺𝐹 = 5.04 × 0.69
𝑃𝑎𝑛𝑒𝑙 𝐺𝑒𝑛𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝐹𝑎𝑐𝑡𝑜𝑟, 𝑃𝐺𝐹 = 3.4776 Wh/Wp/day
Essentially for every Wp of panel capacity, 3.4776 Wh/day can be expected during the lowest
insolation month.
26
- Total Wp of Panel Capacity: 4944.44
3.4776= 1421.797 𝑘𝑊𝑝
- Number of Panels = 𝑘𝑊𝑝
𝑃𝑎𝑛𝑒𝑙 𝑀𝑎𝑥 𝑊𝑝⁄
Number of panels = 1421.797 𝑘𝑊𝑝
420⁄
Number of panels = 3.385232 = 3385.232 ≅ 3386
The 420 figure represents the rated Wp of the Canadian made Heliene 96M420 Monocrystalline
solar panel.
3. Inverter Sizing:
- Maximum Demand = 535 kW
For operational safety, the inverter will be sized at 25% above the maximum demand of the
campus.
Inverter rating = 535 𝑘𝑊 × 1.25 = 668.75 𝑘𝑊 ≅ 700 𝑘𝑊
4. Battery Sizing:
Off Grid Grid-Tie
- Assumed daily consumption = 3803.418 𝑘𝑊ℎ/𝑑𝑎𝑦
- System loss approximation = 85%
- Nominal Battery voltage = 48 V
- Days of autonomy = 3 - Days of autonomy = 4 hrs = 0.1666 Days
- Depth of Discharge = 20%
B.C
= (3803.418𝑘𝑊ℎ
𝑑𝑎𝑦× 3) (0.85 × 0.2 × 48)⁄
Battery Capacity = 1398.315 𝑘𝐴ℎ
B.C
= (3803.418𝑘𝑊ℎ
𝑑𝑎𝑦× 0.16) (0.85 × 0.2 × 48)⁄
Battery Capacity = 74.576 𝑘𝐴ℎ
For an off grid installation, the battery bank should be rated at 48 V, 1398.315 𝑘𝐴ℎ for 3 days of
autonomy. However, for a grid-tie installation, it should be rated at 48 V, 74.576 𝑘𝐴ℎ for 4
hours of autonomy.
27
5. Solar Charger (Charge Controller) Sizing:
- Finding the maximum Voc per module at the lowest recorded temperature in Georgetown
Voc per module (STC @25oC) = 60.55 𝑉
Temperature difference between STC and lowest recorded temp13
:
25 − 16.6 = 8.4 ℃
Voc increase at low temperature: 8.4 × 0.194 = 1.6296
Total Voc at recorded low temperature = 60.55 + 1.6296 = 62.1796 V
- Determining the maximum number of PV modules which can be connected in series:
The number of series connected PV modules shall not exceed the rated maximum Voc of the
charge controller (600 VDC).
2 series connected modules = 62.1796 × 2 = 124.3592 𝑉
3 series connected modules = 62.1796 × 3 = 186.5388 𝑉
9 series connected modules = 62.1796 × 9 = 559.616 𝑉
10 series connected modules = 62.1796 × 10 = 621.796 𝑉
- Finding the number of controllers and modules series strings per controller:
Maximum output current required from charge controllers =
((420 × 3386) (22))⁄ = 64,641.818
Where the minimum assumed battery voltage is 22 VDC
Number of controllers = (64,641.81880⁄ ) = 808
Number of strings = (33869⁄ ) = 376
Number of strings per controller = (808376⁄ ) = 2
Hence on each of the 808, 80A charge controllers 2 strings can be placed. Therefore, each charge
controller will be wired to 18 PV modules.
13 Lowest temperature recorded in Georgetown (16.6 ˚C): http://en.wikipedia.org/wiki/Geography_of_Guyana
28
4.2.3.1.1.3 Designed Campus PV System Specifications
Item Rating Quantity
PV Module
420W Heliene 96M420
Monocrystalline Solar
Panel
STC DC watt Max Power (Pmax) 420 W
3386
Max Power Voltage (Vpp) 49.53V
Max Power Current (Ipp) 8.48 A
Open Circuit Voltage (Voc) 60.55 V
Short Circuit Current (Isc) 9.0 A
Temp Coefficient 0.194 V/˚C
PV Array
420W Heliene 96M420
Monocrystalline Solar
Panel
Peak Size = 3386 × 420 = 1,422,120 𝑊
MPPT Charge Controller
Schneider Electric
Xantrex MPPT 80-600
Max PV Voc 600 Vdc 808
Rated Output Current 80 A
Inverter Module
General Electric
700kW Brilliance Solar
Grid-Tie Inverter
Input Voltage Max 600 Vdc
1
MPPT Voltage Range 300-600 Vdc
MPP Dc Current 2400 Adc
Max Isc 3600 Adc
Nominal Ac Power 700kWAc
Nominal Ac Voltage 480 Vac
Battery Bank
428Ah S550 Rolls
Battery Bank
Off Grid 1398.315 kAh Required 3267
Grid-Tie 74.576 kAh Required 175
29
4.2.3.1.1.4 Designed Campus PV System Land Requirements:
It is estimated that 10,000 sq ft of rooftop or ground area can generate 100kW [22]. As such, for
the designed 1.422MW Campus PV system, approximately 150,000 sq ft is required, equivalent
to 3.44 acres. With the addition of 0.5 acres for onsite facilities, such as housing the Balance-of-
System components, the total site is approximately 4 acres. It is worth mentioning that this figure
is a combination of both direct and indirect land utilization.
Figure 5: University of Guyana Aerial View
Source: https://www.google.com/maps
Utilizing Google Map imagery, an aerial survey of the campus was done to scout a suitable site
to “sit” the designed PV system. Some of the criteria used to select the site were:
- Lack of obstructions or obstacles which can cast a shadow or shade the arrays
- Usability of suitably sized land
- Location and security of site equipment
- Consideration for the type of mounting
- Consideration for fire
- Impact on the environment and surrounding eco-system
- The PV system will interface with the existing electrical network
30
After examining the above mentioned criteria and potential sites around campus, the researcher
selected a 4 acre plot at the back of the campus between the “walk-way” and the recently
constructed National Forensic Laboratory.
N.B. The National Forensic Laboratory isn’t shown in the photo owing to the fact that new
imagery data for Guyana hasn’t been uploaded to Google Maps.
Figure 6: Proposed Site for the Designed Campus PV System
Source: http://www.daftlogic.com/projects-google-maps-area-calculator-tool.htm
Owing to the nature of the selected plot, some amount of site preparation is required prior to the
installation of any equipment. Some of these works include.
- Provision of site access for transportation vehicles, equipment and maintenance:
The proposed site is accessible to personnel and light vehicles for the purpose of surveying and
land demarcation; however a reinforced bridge will have to be constructed to allow heavy
machinery to access to selected site. Two proposed locations are highlighted in the above photo.
- Clearing of vegetation and Grading using earth moving equipment:
Where available the University can utilize its own equipment to minimize equipment rental costs
from a private contractor. However, to mitigate this, the University’s corporate partners or even
the Government (Ministry of Public Works) can be engaged to assist with such undertakings.
31
4.2.3.1.1.5 Designed Campus PV System Mounting Requirements:
For large systems of this nature, it is typical for the ground mounting method to be utilized for
array positioning. This type of mounting is utilized when roof mounting is impractical or not
possible. Mounting is achieved utilizing racks, poles and other foundation elements to support
and secure the arrays [23]. It should be noted that this type of mounting isn’t constrained by
orientation and location issues.
Type Description Typical Grid
Connection
Rack
Typically used for large utility scale projects.
In most instances, rack mounting is used in
non-tracking applications.
Grid-Tie
Ballasted
This type of mounting is utilized in large scale
commercial flat roof and reclaimed landfill
projects, as well as those where pile driving
isn’t possible due to soil composition.
Tracking
As the name suggests, such systems follow the
sun’s position utilizing various control
mechanisms. This form of ground mounting
has superior efficiency when compared with
the other types. A two axes or single axis
approach is usually employed to achieve
tracking.
Pole
This type of mounting utilizes a steel pole,
affixed to a special cross member or rack arm
which allows arrays to be mounted onto its top
or side. The arrays weight allows it to be
balanced, thereby enabling seasonal tilting.
Off Grid
The designed system is non-tracking and grid connected; therefore either the Rack or Ballasted
mounting can be employed to support the arrays. It is worth mentioning that regardless of the
type of mounting implemented, consideration must be given for flooding14
and wind loading.
Unlike solar panels, mounting elements aren’t sold by third party resellers, instead direct contact
must be made with such manufacturers. This is done since these manufacturers offer added
services to their customers such as site surveys and custom designs, among others. This also
allows the manufacturer to guarantee their products warranty for the stipulated duration. As a
consequence the researcher is unable to state the specific number of mounting elements required
to support the designed system or its corresponding estimated cost.
14 The year 2005 in Review, See: http://www.guyana.org/special/year2005.html
32
N.B. It must be said that, utilizing a distributed roof mounting approach for the designed
system is seen as being unfavorable owing to a number of reasons, chief of which is the fact that
a structural and loading analysis must be done for each individual roof structure. The researcher
therefore thought it best to only examine ground mounting.
4.2.3.1.1.6 Designed Campus PV System Angle of Tilt
Arguably one of the most important aspects of the PV system, the angle of tilt dictates how
sunlight will strike the array, allowing the best output to be achieved from the panels. Since the
sun’s position is continually changing, the angle of tilt can be best described as being either fixed
or adjustable [24].
Figure 7: Sun Position and Direction
based on Hemispheric Location
Source: http://www.westechsolar.com/Solar_Information/Collector_Install
ation_Guide.html
The figure illustrates how
consideration for the angle of tilt
changes throughout the year due to
seasonal changes and hemispheric
location.
Based on the University’s
hemispheric location, the designed
system should be oriented due south.
It cannot be overstated, but a tracking system which follows the sun’s ever changing position
would yield the best output. Unfortunately, in some instances the savings garnered from tracking
systems are expensed to maintain the system and ensuring its functionalityvi. Similarly the power
the solar tracker utilizes negates some of its benefits. That said, to compensate, non-tracking
systems usually employ one of two options:
- Addition of more panels with a fixed tilt.
- Utilizing mounting elements that allow for seasonal adjustment.
33
Fixed Tilt Angle:
Figure 8: Site Coordinates
Source: http://itouchmap.com/latlong.html
Using the site latitude and formula “If your latitude is below 25°, use the latitude times 0.87”
𝐹𝑖𝑥𝑒𝑑 𝑇𝑖𝑙𝑡 𝐴𝑛𝑔𝑙𝑒 = 6 × 0.87 = 5.22°
This angle of tilt is from the horizontal. It is said by some, that for fixed tilt PV installations, the
angle of tilt should be as should as close as possible if not equal to the site latitude.
Adjustable Tilt Angle:
Figure 9: Adjustable Angle Calculation
Source: http://solarelectricityhandbook.com/solar-angle-calculator.html
34
An online tool was utilized to perform the above calculations, based on the site location and data.
Mounting elements can be designed to allow for adjustment at the specified angles; however this
will require direct contact with manufacturers.
4.2.3.1.1.7 Designed Campus PV Balance-Of-System Components:
This refers to the mechanical and/or electrical equipment or hardware utilized to assemble and
integrate the PV system to the existing electrical network. The figure below, illustrates a PV
system with the BoS components in the shaded region. Typically, the balance-of-system consists
of wiring, circuit breakers and disconnect/isolation switches, batteries, inverter(s), frames and
supports, surge protectors, lightning arrestors [25], among others. It is through the BoS that the
following can be achieved:
Cost Control Improved Efficiency
Figure 10: PV System with Balance-of-System Components Shaded
Source: A. Malla and A. Niraula: Importance of balance of system in solar PV application
Balance-of-System can be divided into the following broad categories:
Mounting Structure/Elements Cables & Protection Devices
Power Conditioning Units Storage
35
Although some aspects of BoS have been discussed previously, specific considerations for each
category will be outlined below:
Mounting Structure/Elements:
Design
Tilt angle
Orientation
PV array shading
Cables & Protection Devices Proper cable sizing
Efficient wiring methods
Proper Equipment grounding
Wiring protection from Over-current
and Under-current
Storage:
Proper battery sizing
Protecting batteries from overcharging
Minimizing the occurrences of exposed
battery terminals and slack contacts
Power Conditioning Units:
Proper equipment sizing to cater to
specified load(s), power factor and
surge.
It is important to note that, BoS locations should include provisions which allow for the
following:
- Accessibility for maintenance
- Installation of new equipment
- Suitable clearance and workspace
- Ventilation and cooling
- Protection from insects and rodents
36
4.2.3.1.1.8 Designed Campus PV System Material Costing
Item Price
Source Unit Total
420W Heliene
96M420
Monocrystallin
e Solar Panel
$420 $1,422,120 Free Clean Solar
http://www.freecleansolar.com/ShoppingCart.asp
Comment:
Owing to the quantity, the above source does not ship directly to Guyana, hence a US based
freight company will have to be sourced to carry out this process.
Schneider
Electric
Xantrex MPPT
80-600
$1,115 $900,920 Wholesale Solar
http://www.wholesalesolar.com/products.folder/contro
ller-folder/Xantrex-MPPT-80-600.html
General
Electric 700kW
Brilliance
Solar Grid-Tie
Inverter
$700,000*
General Electric
Ground
Mounting $400,000*
S550 428Ah
Rolls Battery
Bank
$1,523 $266,525
https://www.wholesalesolar.com/cart/ $4,975,641
Cabling and
Breakers $150,000*
Miscellaneous 10% Overall Cost
Total Grid-Tie Costing $4,223,521.5 Total Off-Grid Costing $9,403,549.1
Remarks:
- All prices displayed are in USD
- Estimated prices are indicated by a *
37
4.2.3.1.2 Wind Energy:
4.2.3.1.2.1 Wind Data:
With the assistance of rigging personnel, an anemometer was installed atop the 42 metre E-
Governance tower, located on campus. From this sensor a hard-line was used to communicate
with two data loggers mounted at ground level. The data loggers, namely the Logic Energy
Windtracker and Hobo Micro Station, became operational on February 14th
and May 12th
respectively, with the assistance of engineers from the Guyana Energy Agency (GEA). The
researcher made periodic checks to readout data, as well as to ensure the data loggers were
operational and in good working order. Owing to a technical mishap the Hobo Micro Station lost
data recorded prior to May 12th.
4.2.3.1.2.1.1 Logic Energy Windtracker:
This is a cumulative data logger, once initialized it records data on an hourly basis. When data is
“readout” via the memory card slot and subsequently uploaded to http://report.windtrackers.com
all data recorded is illustrated in the appropriate form. A breakdown of the number of hours and
corresponding wind speed is shown, as well as the average wind speed recorded thus far. This
module also shows the direction of wind acting on the wind vane of the sensor.
4.2.3.1.2.1.2 Interpreting the Logic Energy data:
The data in this section was recorded on July 22nd
, 2014 and the images below were sourced
from http://shop.logicenergy.com/pages/windtracker.
Figure 11: Logic Energy Windtracker illustration of Campus Wind Data using a Histogram
38
The figure above illustrates all the wind data recorded at the last readout. As can be seen the
most observed wind speed is 5m/s with at a total of 1186.3 hrs of observation, followed by 4m/s
at 928.2 hrs and lastly 6 m/s at 725.3 hrs. The occurrence of 2-3m/s wind speed can be
considered to be calm periods, while the occurrences of 7-10 m/s wind speed can be considered
to be periods of gust. It can therefore be said that, the campus receives an average wind speed
between the range of 4-6 m/s.
Figure 12: Logic Energy Windtracker illustration of Campus Wind Data using Wind Rose Intensity
The Wind Rose Intensity diagram above, illustrates the direction in which wind is strongest and
frequently occurring. This information is important since it allows a determination of the best
location to sit wind turbines.
Examining the image, it can be observed that the 4-6 m/s wind speed range has a total frequency
of 76.42% with a direction of 22.5˚. It can be said that any wind turbine situated on campus
should be oriented within North to North East direction.
It was however, highlighted by one of the engineers for GEA that the vane on the anemometer
was not positioned in the true North direction, but rather Northeasterly. As such the wind rose
data is skewed by a few degrees. After consultation it was indicated that the wind rose data,
although skewed, can be corrected by simply taking the offset angle into account.
The researcher is unable to make this correction but the statement regarding the turbine
orientation still holds true, based on pertinent data.
39
4.2.3.1.2.1.3 The Hobo Micro Station:
This is a four sensor data logger, optimized to allow monitoring of one or more locations15
. This module differs from the Logic Energy
module in the sense that, its sampling or logging interval can be adjusted. When initialized, the logging interval was set to 1 hour. The
wind speed is determined by, counting the number of revolutions made on the anemometer and dividing this figure by the sampling
interval expressed in seconds. It is important to note that this module allows for more informed conclusions to be drawn when
examining its data.
4.2.3.1.2.1.4 Interpreting the Hobo Micro Station data:
15 See Hobo Micro Station 7645-L Manual
40
The data in this section was recorded on July 22nd
, 2014 and the image above was sourced from
the HOBOware Pro software.
A close examination of the HOBOware plot reveals very important information related to the
wind speed experienced on campus. It can be seen that during the course of the day the campus
experiences wind speeds in various clusters. These clusters can be grouped as follows, 0-3 m/s,
4-6 m/s and 7-9 m/s. The latter cluster occurs less frequent, and can be said to be a random
occurrence at best. Similar to the Logic Energy Windtracker data, the 4-6 m/s cluster seems to be
the most predominant. One intriguing observation, when examining the HOBOware plot, is that
the wind speeds occur at varying portions of the day. For instance, the 4-6 m/s cluster can occur
around noon on one day, and occur during the later afternoon or evening on another. That said,
one cannot definitively say which period of the day is best for producing wind energy.
4.2.3.1.2.2 Estimated Output Utilizing Wind Data:
Figure 13: Typical Wind Turbine Power Curve
Source: http://shop.logicenergy.com/pages/windtracker-info
In order to determine the power which can be generated by a wind turbine, its power curve is
utilized. Merging the Logic Energy Windtracker data with this typical power curve, a picture
begins to immerge as to how much energy can be generated.
41
Wind Speed [m/s]
Hrs Power Curve
[kW] Energy Generated
[kWh]
2 265.3 0 0
3 415.5 0 0
4 928.2 2 1856.4
5 1186.3 4 4745.2
6 725.3 7 5077.1
7 174 10 1740
8 18.8 14 263.2
9 2.8 17 47.6
10 0.3 19 5.7
Total 3716.5 13735.2 kWh
Table 12: Energy Potential
As of July 22nd
2014, the Logic Energy module has been in operation for 3716.5 hrs or 154 days.
The energy potential table illustrates how much energy would have been produced during that
time period. Based on the energy potential findings it becomes apparent that a low speed turbine
is better suited for campus use. This is reiterated when observing that the “cut-in” and “start-
up” speed for most turbines are typically 3.5 m/s and 6m/s respectively. It is of importance to
note that because the 4-6 m/s cluster holds favorable potential, turbine choice should make full
use of this cluster’s potential.
4.2.3.1.2.3 Feasibility of Utilizing Wind Energy for Campus Power
Based on the previous sections, the question of feasibility begs to be asked. With that said, the
researcher will discuss common benchmarks16
used to address the feasibility of utilizing wind
energy for campus power.
- Noise Impact:
Because a wind turbine consists of rotating parts, noise is an innate aspect of electricity
production. It is said that manufactures are currently utilizing various techniques to reduce the
amount of noise produced by turbines, however it is a factor of some concern. In most instances
noise limits the installed capacity of wind farms, especially when considering proximity to
residential areas, and in this case classrooms and students. It can therefore be said, that owing to
the wind speeds which propagate the campus, the installed capacity will be considerable, and
consequently noise production/pollution to the surroundings will be significant.
16 See http://www.renewableenergyworld.com/rea/news/article/2009/04/wind-farm-design-planning-research-and-
commissioning
42
- Visual Impact and Flicker:
As mentioned in previous section, the installed capacity of a wind farm on campus would be
considerable. Be that as it may, the resulting visual impact will be staggering. Imagine a once
clear field or open plot of land, filled with the slow rotating blades of wind turbines, this won’t
be aesthetically pleasing to everyone.
As part of the visual impact consideration, flicker becomes a concern. Flicker is the shadow
caused by the rotating blades of a wind turbine. Essentially more turbines equate to a greater
amount of flicker to be considered. If oriented and placed correctly flicker shouldn’t be a major
issue unless the shadow cast affects students on campus.
- Gird (Campus) Stability/Connection:
The 4-6 m/s cluster doesn’t occur during a fixed portion of the day. With that in mind, recall the
University’s peak demand occurs during the course of the day and not in the evening. It becomes
apparent that wind conditions needed to drive the turbines to product the necessary electricity to
meet the campus’s electricity demand might not always exist during the day. A connection of
this nature can be described as intermittent17
at best, meaning that at instances when wind speed
isn’t sufficient to drive the turbines to produce their rated output, the campus will need to source
power from the GPL supply.
Concluding Remarks:
As previously mentioned, the wind data was recorded at a height of 42 metres. One could
therefore propose the utilization of higher hubs in order to tap into stronger wind currents,
however intermittence, foundation and other factors will need to be addressed. However, based
on the data presented and all factors considered, it can be said that wind power would not be
capable of supplying power to the University’s campus as a single source. It must be combined
with another more reliable source, but its intermittence must be catered to ensure supply stability.
17 See
http://www.umass.edu/windenergy/publications/published/communityWindFactSheets/RERL_Fact_Sheet_2a_Capa
city_Factor.pdf
43
4.2.3.1.3 Bio-Energy:
As described in the literature review, bio-energy, is said to be energy produced from either plant
or animal based organic matter. With this definition in mind, the researcher thought it best to
outline possible bio-energy avenues the University can undertaken.
4.2.3.1.3.1 Potential Bio-Energy Avenues:
4.2.3.1.3.1.1 Rice Husk:
This is the exterior protective encasing of a rice grain. It’s larger than the rice grain, convex in
shape and is yellowish in color. In Guyana rice husk is usually discarded, left in open fields to
the elements or burnt by millers at the end of rice production processvii
. With an abundance of
rice husk locally, the University can seek to invest in a rice husk power plant, commonly termed
rice husk gasifier. This plant utilizes the gasification process, which consists of a set of chemical
reactions that use a small amount of oxygen to convert the rice husk into syngas, which is used to
produce electricity.
It is estimated that the production of 1kW of power requires 1.30~1.85 kg of rice husk. Hence to
supply 700kW to the campus approximately 910~1295 kg of rice husk is required. Owing to
advances in technology water supplied to the plant is recycled to prevent harm to the
environment.
Should the University, go the route of acquiring a plant of this nature, the following should be
taken into account:
- Transportation: Rice husk is not native to the campus and therefore it will have to be
transported to an onsite facility from a rice mill. Enclosed vehicles should be utilized to
prevent dust content within the husk from posing a hazard to motorists, pedestrians and the
environment. This will also ensure the preservation of the moisture content within the husk.
This cost should be factored into the overall feasibility assessment for the establishment of
such a plant on campus.
- Moisture Content: Every rice husk plant is designed to operate within a moisture
content18
tolerance, usually stipulated by the manufacturer. This tolerance is of importance
since it becomes difficult for the plant to operate effectively outside the specified range;
usually igniting the husk is problematic. To ensure safe operation, the moisture content
should be checked prior to removal from the mill and before it is added to the plant.
18 See http://cturare.tripod.com/fue.htm
44
- Storage: This serves as a quality control and protective measure, ensuring the
moisture content is kept at an acceptable level. This will also eliminate environmental
concerns about air pollution. The storage area19
will allow for testing and monitoring of the
husk. It is envisioned that some form of husk storage (e.g. a shed) will be established at the
mill to serve as a loading centre as well as to aid in preserving the favorable properties of the
rice husk.
Apart from the above mentioned considerations, the value added nature of rice husk should be
taken into account. At the end of the process, the ash produced can be utilized in a variety of
applications, such as in fertilizers and in production of high strength concrete.
Typical Rice Husk Power Plant Specifications:
The information below summarizes specifications for a 700 kW Rice Husk Power Plant,
manufactured by Shangqiu Haiqi Machinery Equipment co. ltd. Wooden containers are used to
ship the assembly to the customer and engineers are sent to assist with the assembly and training
of personnel.
Cost $10,00 – 100,00 USD
Warranty 1 year
Moisture Content 15-20%
Power Consumed 5-15 kW
Fuel Consumption 500-1000 kg
Output Voltage 220 V, 380 V, 400 V, 600 V
Weight 10-40 t
Raw Material Rice husk, wood pellets, saw
dust, bagasse, etc
Cooling Method Water Cooling
Maintenance & Servicing Engineers available as needed
Supplier: http://haiqimachine.en.alibaba.com/product/1468126695-
212084418/Haiqi_brand_700kw_biomass_gasifier_generation_power_plant_for_industry.html
19 See
http://www.bilaspuruniversity.ac.in/PDF/CollegeCorner/Collaborative%20Study%20ICBL%20and%20Bilaspur%20
Vishwavidyalaya%20%281%29.pdf
45
4.2.3.1.3.1.2 Bio-energy:
As of late bio-energy has been gaining attention locally, in the form of biodiesel. Biodiesel
power plants as the name suggests use biodiesel as opposed to diesel to produce electricity.
Biodiesel is produced from the chemical reactions between natural oils and alcohol. It can be
made from vegetable oil or fat.
In order to undertake a biodiesel imitative it is advised that the University partner with the
Guyana Sugar Corporation (Guysuco) and the Institute of Applied Science and Technology
(I.A.S.T) in order to examine possible biodiesel avenues. This partnership will allow the
University to garner the requisite knowledge as it relates to the establishment of a biodiesel
production plant and other areas of biodiesel agreement.
4.3 Objective Two
4.3.1 Current Campus Consumption:
As indicated in the “Determination of Campus Consumption & Demand” section, the
University’s estimated monthly electricity consumption is estimated at 117905.97 kWh. This
value is an illustration of the loads connected to the campus’s electricity network. These loads
include lighting fixtures, air-conditioning units, fans, laptops, printers and other office
equipment, among others.
Examining a Report [26], Energy Audit of Technology Building, complied by a former student, a
holistic view of the University’s consumption can be painted. Extrapolating key points from the
analysis done on the “Technology Buildings” it can be conceived that most of the University’s
consumption can be attributed to lighting. That said, any energy measure which seeks to reduce
consumption, must do so with a view of encompassing all connected loads.
4.3.2 Suggested Consumption Reduction Measures:
Below are a few measures which can be undertaken to reduce campus consumption:
- Use of LED Lamps: LED (Light Emitting Diodes) technology has become popular in
recent years owing to a number of factors20
, some of which are longer lasting, more efficient,
durable and cost-effective. The only deterrent to the implementation of LED lamps is the
20 See http://eartheasy.com/live_energyeff_lighting.htm#led
46
initial cost; this can be likened to the implementation energy saving bulbs a few years ago, at
the time it was said that the high cost outweighed the benefits.
A T8 LED tube costs approximately $10-20USD, this cost varies based on quantity.
- Comprehensive Examination & Upgrade of Existing Electrical Network: From an
observers perspective, one can notice defective security lamps that are “on” during the day
and “off” at night, an antiquated wiring system, which can be seen as an electrical hazard
only awaiting the right mix of factors to malfunction. It can therefore be envisioned that
some aspect of the University’s consumption can be attributed to “slack connections” and the
old wiring which make up the electrical network.
A complete top-to-bottom examination of the electrical network is needed, and if necessary
an immediate overhaul should be undertaken.
47
4.4 Objective Three
4.4.1 Solar Power Implementing Guide
The manual below was modified from a generic template to suit country specific factors, non-
applicable aspects were omitted.
Source: http://www.leonics.com/support/article2_12j/articles2_12j_en.php
1. Determine power consumption demands The first step in designing a solar PV system is to determine the total power and energy
consumption of all loads that need to be supplied by the solar PV system.
1.1 Calculate total Watt-hours per day for each appliance used:
Add the Watt-hours needed for all appliances together to get the total Watt-hours per day which
must be delivered to the appliances.
𝑇𝑜𝑡𝑎𝑙 𝑊𝑎𝑡𝑡 − ℎ𝑟𝑠 = ∑(𝐴𝑝𝑝𝑙𝑖𝑎𝑛𝑐𝑒 𝑊𝑎𝑡𝑡 𝑟𝑎𝑡𝑖𝑛𝑔 × 𝐻𝑟𝑠 𝑜𝑓 𝑜𝑝𝑒𝑟𝑎𝑡𝑖𝑜𝑛)
1.2 Calculate total Watt-hours per day needed from the PV modules.
Multiply the total appliances Watt-hours per day times 1.3 (the energy lost in the system) to get
the total Watt-hours per day which must be provided by the panels.
2. Size the PV modules Different size of PV modules will produce different amount of power. To find out the sizing of
PV module, the total peak watt produced needs. The peak watt (Wp) produced depends on size
of the PV module and climate of site location. We have to consider “panel generation factor”
which is different in each site location. For Guyana, the panel generation factor is 3.47. To
determine the sizing of PV modules, calculate as follows:
2.1 Calculate the total Watt-peak rating needed for PV modules
Divide the total Watt-hours per day needed from the PV modules (from item 1.2) by 3.47 to get
the total Watt-peak rating needed for the PV panels needed to operate the appliances.
2.2 Calculate the number of PV panels for the system
Divide the answer obtained in 2.1 by the rated output Watt-peak of the PV modules available to
you. Increase any fractional part of result to the next highest full number and that will be the
number of PV modules required.
N.B. The Result of the calculation is the minimum number of PV panels. If more PV modules
are installed, the system will perform better and battery life will be improved. If fewer PV
48
modules are used, the system may not work at all during cloudy periods and battery life will be
shortened.
3. Inverter sizing An inverter is used in the system where AC power output is needed. The input rating of the
inverter should never be lower than the total watt of appliances. The inverter must have the same
nominal voltage as your battery.
For stand-alone systems, the inverter must be large enough to handle the total amount of
Watts you will be using at one time. The inverter size should be 25-30% bigger than total
Watts of appliances. For instance, if the appliance type is a motor or compressor then inverter
size should be at a minimum 3 times the capacity of those appliances and must be added to
the inverter capacity to handle surge current during starting.
For grid tie systems or grid connected systems, the input rating of the inverter should be
same as PV array rating to allow for safe and efficient operation. However, it is
recommended that the inverter be sized larger than the system, to cater for load growth.
4. Battery sizing The battery type recommended for using in solar PV system is deep cycle battery. This type of
battery is specifically designed to be discharged at low energy level and rapid recharged or cycle
charged and discharged day after day for years. The battery should be large enough to store
sufficient energy to operate the appliances at night and cloudy days. To find out the size of
battery, calculate as follows:
4.1 Calculate total Watt-hours per day used by appliances.
4.2 Divide the total Watt-hours per day used by 0.85 for battery loss.
4.3 Divide the answer obtained in item 4.2 by a suitable depth of discharge.
4.4 Divide the answer obtained in item 4.3 by the nominal battery voltage.
4.5 Multiply the answer obtained in item 4.4 with days of autonomy (the number of days that
you need the system to operate when there is no power produced by PV panels) to get the
required Ampere-hour capacity of deep-cycle battery.
𝐵𝑎𝑡𝑡𝑒𝑟𝑦 𝐶𝑎𝑝𝑎𝑐𝑖𝑡𝑦 (𝐴ℎ) = (𝑇𝑜𝑡𝑎𝑙 𝑊𝑎𝑡𝑡 𝐻𝑟𝑠 × 𝐷𝑎𝑦𝑠 𝑜𝑓 𝐴𝑢𝑡𝑜𝑛𝑜𝑚𝑦)
(0.85 × 𝐷𝑒𝑝𝑡ℎ 𝑜𝑓 𝐷𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒 × 𝑁𝑜𝑚. 𝐵𝑎𝑡𝑡𝑒𝑟𝑦 𝑉𝑜𝑙𝑡𝑎𝑔𝑒)
N.B. For grid-tie systems, the days of autonomy should be expressed in hours, typically 2-4 hrs
is used. This is due to the fact that, in the event of a blackout, a backup generator will take the
place of the grid, until power is restored by the utility. For high dependency systems like
hospitals, this figure should be higher to cater for catastrophic grid failure, e.g 1-2 days. On the
other hand, for standalone systems, the days of autonomy typically chosen is 7 days, and this is
dependent upon cloud over.
5. Solar charge controller sizing The solar charge controller is typically rated against Amperage and Voltage capacities. Select the
solar charge controller to match the voltage of PV array and batteries and then identify which
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type of solar charge controller is right for your application. Make sure that solar charge controller
has enough capacity to handle the current from PV array.
For the series charge controller type, the sizing of controller depends on the total PV input
current which is delivered to the controller and also depends on PV panel configuration
(series or parallel configuration).
For the MPPT type charge controller, the following should be done:
• Name-XXYY (XX is nominal battery voltage, YY is maximum charge current)
• Find out what is nominal battery voltage that charge controller will charge and select XX
• Find out what is Wp of PV module and
• Select the suitable charge current (CC) = (Wp) / XX
• Find out YY by multiplying CC and the safety factor (NEC requirement) = (CC) x 1.2
• Check that Vpm(system) is in range that Name-XXYY can handle (MPPT voltage range)
• If PV modules are in series, need to check that Vpm(system) = Vpm(module) x Module in
series
• If PV modules are in parallel, need to check that Vpm(system) = Vpm(module)
• Check that Voc(system) is not more than Name-XXYY range (Maximum open circuit voltage)
• If PV modules are in series, need to check that Voc(system) = Voc(module) x Module in series
• If PV modules are in parallel, need to check that Voc(system) = Voc(module)
According to standard practice, the sizing of solar charge controller is to take the short circuit
current (Isc) of the PV array, and multiply it by 1.3
𝑆𝑜𝑙𝑎𝑟 𝑐ℎ𝑎𝑟𝑔𝑒 𝑐𝑜𝑛𝑡𝑟𝑜𝑙𝑙𝑒𝑟 𝑟𝑎𝑡𝑖𝑛𝑔 = 𝑇𝑜𝑡𝑎𝑙 𝑠ℎ𝑜𝑟𝑡 𝑐𝑖𝑟𝑐𝑢𝑖𝑡 𝑐𝑢𝑟𝑟𝑒𝑛𝑡 𝑜𝑓 𝑃𝑉 𝑎𝑟𝑟𝑎𝑦 × 1.3
- Mounting requires consultation with PV installers to determine suitable supports based on the
intended application.
- Online Resources:
- http://www.solarelectricityhandbook.com/solar-calculator.html
- http://www.energymatters.com.au/climate-data/cable-sizing-calculator.php
4.4.2 Wind Energy Implementing Guide
1. Site Selection:
- To determine wind resource
- To identify any impediments that would prevent site development
- To select preliminary site boundary and identify legal requirements
- To develop preliminary site design
2. Assess Project Feasibility:
- To develop cost analysis
- To perform onsite wind monitoring
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3. Detailed Assessment:
- To undertake a detailed site specific investigation to enable an assessment of the project
and possible wind turbine layout
4. Planning and Environmental Approval:
- To prepare the documental necessary for regulatory and community or residential (if
necessary) assessment of the project
- To undertake any necessary environmental referrals and permit documentation
5. Construction:
- To finalize the overall project cost
- To finalize the design and produce construction drawings
- To prepare the required management plans in accordance with the conditions of approval
prior to construction
- To obtain all pre-construction approvals and permits
- To undertake construction of the project within predetermined guidelines and endorsed
management plans
- To monitor compliance with any relevant conditions of approval and management plans
during the construction phase
6. Operation:
- To undertake the operation of the wind farm in accordance with any operational
conditions and guidelines based on management plans, as well as ensuring compliance
7. Decommissioning:
- To identify whether the site can be redeveloped after decommissioning
- To ensure decommissioning occurs within acceptable standards
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Chapter Five: Recommendations & Conclusion
5.1 Chapter Introduction:
This chapter seeks to outline recommendations and develop conclusions based on the outcomes
of the Results and Analysis Chapter.
5.2 Objective One:
The researcher recommends the following, should the University consider implementing an
alternative energy project.
5.2.1 Solar Energy:
As can be seen some aspects of the design may appear vague, this is only due to the fact that the
researcher was unable to garner the requisite information and hands-on-knowledge needed to
pronounce on said aspects, as such estimations where used to supplement. With this report as a
base or reference, it is recommended that the University consult with a PV installer. The installer
will make modifications where necessary to improve the design.
5.2.2 Wind Energy:
With the data examined, although the 4-6 m/s cluster is favorable, it falls below the average wind
speed needed to generate rated power. That said, it is recommended that more data be gathered at
varying heights to make a conclusive decision, as to whether wind energy can be generated to
provide campus power.
5.2.3 Bio-energy:
At best, the bio-energy option would see the University partnering with corporate entities more
versed in the field. For instance, should the University acquire a biodiesel capable generator, a
fuel agreement could be arranged with IAST. On the other hand, UG can go the route of
acquiring its own biodiesel production equipment and generator, and can partner with said
entities for training and initial assistance with maintenance. Nonetheless, UG must partner to
become more informed about the technology.
5.2.4 Concluding Remarks:
Alternative energy is undoubtedly the future of electricity generation. Every year improvements
are made to the existing technologies, while research and development continues to birth new
technologies. In Guyana, alternative energy measures are being implemented at varying levels,
and in the near future widespread use is envisioned. As such the University should seek to
establish an Alternative Energy Research Lab. This facility will allow students to work on
alternative energy projects, conduct research and be able to gain hands on exposure. In order to
establish the facility the University should partner with other Institutions both local and foreign.
It is worth mentioning, of the three alternative energy sources examined, solar energy seems the
most favorable, and despite its cost the technology is tried-and-true.
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5.3 Objective Two:
The University needs a more proactive conservation campaign. Posting “Please turn off
lights when not in use” notices in classrooms is a good measure. However it is believed that
this measure falls short of its desired goals. The University’s conservation drive must be
taken to the students in a more direct manner, whether it is in the form of consultations or
discussions.
Implementing energy saving technologies as pilot projects. For instance, UG could utilize
LED security lamps in a section of the campus or T8 LED tubes in a few classrooms, to
examine their functionality. After monitoring, if their use has found favor, implementation
can be done on a larger scale.
Recommendations regarding the electrical network have already been mentioned; however
the researcher suggests immediate consultation with an electrical contractor. Their
recommendations should be taken under advisement and where necessary corrective
measures should be undertaken.
It would be remiss of the researcher not to mention work done by previous students regarding
energy conservation measures. As such it is recommended that conservation measured
outlined in the “Redesign and modeling of the UG’s Turkeyen Campus Electricity
Distribution System to cater for the World Bank Infrastructure Project” and “Energy Audit of
Technology Buildings” Reports by Saleem Abdool and Kevon Grimmond respectively, be
reexamined to determine their feasibility.
5.4 Objective Three:
It is recommended that supplementary resources be utilized in conjunction with the
manuals/guidelines prepared in section 4.4. This is due to the fact that they were prepared from
an introductory perspective and can be seen as basic at best.
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End Notes
i http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/how-geothermal-energy-works.html ii http://en.wikipedia.org/wiki/Coal iii http://eetd.lbl.gov/ee/ee-1.html iv http://longerhealthylife.net/Ecology.html v http://www.stabroeknews.com/2013/news/stories/11/04/airport-runway-extension-begun-cjiac/ vi http://solartradingpost.com/solar-angle-calculators.html vii http://www.kaieteurnewsonline.com/2012/01/04/special-ministerial-team-tackling-cane-grove-rice-dust-pollution/
