Recovering Waste Heat from Photovoltaic Panels
April 18, 2016
Spring 2016
Team Members:
Taylor McLemore
Harold Microutsicos
Chris Lambrecht
Alexander Smith
Mark LaVigne
Trenton Miller
Keira Flanagan
MAE 434W / MAE 435
i
TABLE OF CONTENTS
TABLE OF CONTENTS ................................................................................................................. i
LIST OF FIGURES ........................................................................................................................ ii
ABSTRACT ................................................................................................................................... iii
INTRODUCTION .......................................................................................................................... 1
METHODS ..................................................................................................................................... 2
Methods Overview ...................................................................................................................... 2
Completed Methods .................................................................................................................... 2
RESULTS ....................................................................................................................................... 7
Structural Design ......................................................................................................................... 7
Electrical...................................................................................................................................... 7
Test Results ................................................................................................................................. 8
DISCUSSION ............................................................................................................................... 10
CONCLUSION ............................................................................................................................. 13
APPENDICIES ............................................................................................................................. 14
Appendix 1. Budget................................................................................................................... 14
Appendix 2. Calculations .......................................................................................................... 17
Appendix 3. Electrical Schematic ............................................................................................. 20
Appendix 4. Gantt Chart ........................................................................................................... 21
REFERENCES ............................................................................................................................. 22
ii
LIST OF FIGURES
Figure 1. Electrical junction boxes for resistors and breakers…………………………………... 3
Figure 2. Full CAD Model of PV racking system and base support…………………………….. 4
Figure 3. Completed rig, front view………………………………………………………………5
Figure 4. Completed rig, rear view……………………………………………………………......6
Figure 5. Autodesk Inventor model deflection analysis…………………………………………. 7
Figure 6. Hourly temperature readings, April 10………...………………………………………. 8
Figure 7. Cost Analysis...………………………………………………………………………...14
iii
ABSTRACT
Clean, renewable energy can be sourced from a variety of natural occurrences without
inducing any harm on the environment. These alternatives to fossil fuels lack efficiency when
converting free energy into usable electricity. One such alternative energy source is the capturing
of solar energy through photovoltaic panels.
When capturing solar energy with photovoltaic (PV) panels, decreased efficiency is directly
related to increased panel surface temperatures. The technique of active cooling with a heat
exchanger unit is one method used to reduce panel temperature. A heat exchanger’s ability to
recover heat may be limited by the conductivity of the material it is made of, the surface color,
and the size. One example of a heat exchanger is the SunDrum (SunDrum Solar, Hudson, MA)
heat recovery unit. In order to determine which of the hypothesized areas of limitation require
modification, the SunDrum devices must be tested in conjunction with PV panels and compared
directly to panels not equipped with a heat exchanger.
In order to test these devices, a rig was designed to support an array of six panels, three with
SunDrum and three without, with the ability to move to testing locations with optimal sunlight.
The panels will be set to an angle of 45 degrees to maximize the amount of sunlight that will be
collected during the months of testing. A Tigo data acquisition system (Tigo Energy, Los Gantos
CA.) will be used to measure the power output of the panels while an infrared thermometer gun
will be used to periodically measure their temperatures. The gathered data will be used to
determine which of SunDrum’s limitations could be optimized to maximize the amount of heat
which can be recovered in the tank.
1
INTRODUCTION
The need for clean, renewable sources of energy such as geothermal, hydroelectric, wind,
and solar is an issue at the forefront of modern science and technology. Of all of these options,
solar is one of the more accessible forms of energy due to the fact that sunlight always reaches
the surface of the Earth in some capacity during the day, even if it is cloudy. This sunlight can be
harvested through the use of photovoltaic (PV) panels with an average efficiency of 20%. This
efficiency can be further increased through the use of cooling techniques, since efficiency
decreases when the panel is heated [1,2,3].
Solar irradiance (the amount of the sun’s solar radiation that strikes a given surface),
which is limited by common foreign objects such as dust, must be optimized for a given PV
system’s efficiency potential to be achieved [4,5]. There are various ways to cool PV panels,
most of which can be grouped into two categories, passive cooling and active cooling. Passive
cooling relies on fins to remove heat from the panels. While these involve less complex and
inexpensive setups, they are not as effective in increasing the efficiency as active cooling
methods and are not ideal in regards to utilizing the waste heat [1]. On the other hand, active
cooling relies on the use of working fluids such as air or water to remove heat from the panels
[2,4]. Active cooling can be achieved through the use of a heat recovery unit, such as the
SunDrum Heat Recovery System, which utilizes a closed loop to pass fluid over the back of the
panels, increasing efficiency and allowing for waste heat to be used for domestic hot water
purposes. While the theoretical average thermal energy production per day under optimal
conditions (no cloud cover and proper angle) for 8 SunDrum units during a sample month of
October was found to be 462.753 MJ [6], experimental data was never collected to determine the
2
accuracy of this claim. Therefore, the purpose of this project is to design and build a mobile PV
rig which will allow for the testing and analysis of the heat recovery capabilities of the SunDrum
system and its ability to supply hot water for domestic use. Based off the analyzed data and
results, methods of further increasing the amount of heat recovery will be proposed.
METHODS
Methods Overview
A mobile PV mount was designed and built to support six panels at an angle of 45
degrees as well as hold the necessary electrical and plumbing equipment. Of the six panels, three
were equipped with SunDrum, to compare to the baseline performance of those without heat
recovery units. With the rig completed, the plumbing connections between the SunDrum units
and the hot water tank were installed and the electrical connections for the panels and Tigo data
acquisition system will be made. Testing of the rig was then planned to be held during the
months of March and April in Norfolk, Virginia and all necessary data for the analysis of
SunDrum’s effectiveness was collected.
Completed Methods
A mobile testing unit, consisting of a lower base made from pressure treated southern
yellow pine 2”x10” lumber was designed and built, to support the UNIRAC (UNIRAC Inc.,
Albuquerque, NM) solar mounting system. A major factor of the original design was the
operational requirement of the inverter, which required the use of six panels to run properly,
three of which were equipped with the SunDrum heat exchangers. Upon further analysis, it was
3
discovered that the inverter was intended for domestic use
where it would connect to the power grid, and would not
function for a stand-alone off the grid system. A new way
to provide a load for the panels was designed, which
involved the use of a heatsink for each panel’s string. The
necessary components for the new system, which include
the heatsinks, weather rated enclosures (Figure 1), and
double pole circuit breakers for each of the two strings of
three panels in series was ordered. Even though the system
of six panels was designed around using the older inverter,
the design was still beneficial to the project because it
increased the overall accuracy of the data that was
Figure 1-Electrical junction boxes for
resistors and breakers
measured.
The UNIRAC solar mount housed the PV panels. It was constructed with aluminum
crossbars and 2” steel roller bars, and scaled for the number of panels used. Using the material
properties of steel, measurements of the roller bars, the material properties of aluminum and
measurements of the crossbars, the total weight of the UNIRAC solar mount was calculated, as
this information was not listed on the data sheet. This value was summed with the weights of the
remainder of the system components, as found on their respective data sheets, resulting in a
value for the total weight that the base would have to support. This value was used to create a
CAD model (Figure 2) of the proposed design using Autodesk AutoCad (AutoDesk Inc., San
Rafael, CA). A stress and displacement analysis with the calculated total weight was then
4
performed on the CAD model by importing it into Autodesk Inventor. As shown in Figure 5, the
point load (yellow arrow) placement was determined by finding the contact points of the solar
array structure and the base structure. The constraints of the materials were modeled in
accordance to where the roller jacks are placed.
The wooden base (purple parts of Figure 2)
was constructed and reinforced with angle irons and
joist hangers. The UNIRAC (red parts of Figure 2)
was then mounted to the wooden base. Four wheel
jacks were mounted to the base to make it mobile in
order to be moved to the testing location from the
storage site. The solar panels and SunDrum units
were then mounted to the UNIRAC, and the rigid
board reflective insulation for the SunDrum units was
attached. Platforms were added to the wooden base
between the main joists to hold electrical and plumbing
Figure 2- Full CAD Model of PV racking
system and base support.
components, which marked the end of the construction phase, and the start of the connection
phase, in which the electrical and plumbing systems were installed.
In order to evaluate panel temperatures and power production, it was necessary to
accurately record panel function data. Tigo data acquisition systems can be arranged to capture
real time data on the energy produced by the panels. After installing the electrical connections,
the plumbing for the SunDrum units needed to be properly installed so as to allow the flow of a
working fluid of water. The circuit works by allowing the fluid to flow through the KS pump
5
station, into the SunDrum panels, (three of which were aligned in series), to the solar hot water
tank, and finally back to the KS pump station. The pump station was then mounted to the
wooden base and all necessary connections to the components were made with a ⅜” flexible,
insulated pipe. After all the connections were made, the closed loop system was charged with
water, the tank was filled with the appropriate amount of water (15 gallons per heat recovery
unit, for a total of 45 gallons), and the water side assembly was completed. It was found from
accessible data online that for Norfolk, Virginia, (latitude 39.916 degrees north), the optimum
solar angles for the planned months of testing (January, February, and March) are 37, 45, and 53
degrees respectively. The angle of the rig was set at 45
degrees, the average of these three values (Figure 2).
Testing commenced as soon as the electrical and
plumbing systems were complete, which ended up
being later than planned, towards the end of March.
Testing occurred on clear days, or as clear as possible,
during peak sun intensity hours: from approximately
10 a.m. to 4 p.m. This ensured that the maximum
amount of solar irradiance was in contact with the
solar panels, so as to gather hourly power and
temperature readings.
Figure 3-Completed rig, front view
The Tigo data acquisition system provided the
power which was output by each string of panels. The data was analyzed to assess and quantify
the power increase provided by the SunDrum system as contrasted to the panels without.
6
With the data collected, the weaknesses of the SunDrum units were analyzed in order to
propose and implement modifications to the product. From observation of the units and the
insulation provided, expected limiting factors of the functionality of the product have been have
been predicted, giving reasoning to collect certain data points.
The insulation provided by SunDrum
consists of rigid board insulation, with a reflective
surface on both sides (Figure 4). The insulation,
which consists of two 35 ½”x 23”x ½” boards,
does not cover the entire surface area of the
SunDrum, which is 35 ½” x 50”. This leaves 142
square inches uninsulated which allowed for
recovered heat to be lost to the ambient, therefore reducing
Figure 4-Completed rig, rear view
the amount of usable recovered heat. In order to calculate
an approximate measure of heat loss from the system into the ambient, a value for total specific
heat of the PV panel must approximated, and the volume of water in the hot water tank must be
known. This value was compared with the amount of heat that is delivered to the hot water tank,
by measuring the change in temperature in the water over time. The value collected included the
heat loss through the tubing of the system, however, that was assumed to be negligible as the
tubing was well insulated.
7
RESULTS
Structural Design
The initial results of the project were the complete
models of the solar array and the base structure. After the
size of the solar array was determined, it was designed in
AutoCAD (Figure 2). The UNIRAC was designed to be
set at an angle of 45 degrees, which was the average sun
angle of the three months that testing will occur. In order
to complete the design for the base structure, a load
analysis was performed to determine what material
should be used (based on the rig’s weight), as well as to find
Figure 5- Autodesk Inventor model
deflection analysis
the associated deflections and reaction forces at the roller jacks. Using the material properties of
southern yellow pine, the results of the analyses showed a small deflection of .04513 inches in
the middle of the structure when using pressure treated southern yellow pine 2”x 10” lumber
(Figure 5) and proved that the jacks would be able to support the weight of the structure.
Electrical
After determining that the inverter which was donated would not be of use for this
particular setup, and a new method of “power dumping” was derived. Before deciding to use the
aforementioned variable resistance heatsinks, calculations needed to be performed to determine
whether they would be able to provide a substantial resistance for the panels to operate while
keeping the current in a safe range to prevent electrocution (Appendix 2). The resulting design
current was found to be about 2 amps. While contact with a current of this magnitude will still be
8
dangerous, it is far less than any of the other resistors which were tested. With this in mind, the
design power which would be provided by the resistors was found to be, under ideal conditions,
about 180 Watts.
Test Results
After analysis on the day which had the best weather conditions, the total heat transferred
to the tank during the test session was found to be roughly 15900 kJ (Appendix 2). This value
was based on the beginning and final temperature in the water tank. To compare how well
Sundrums were performing, the amount of solar insolation which was striking the surface of the
panels was calculated. With this value, the theoretical electrical power output was found as well
as the amount of heat that was absorbed by the panels. Knowing how much heat was absorbed by
both the tank and panels, the approximate efficiency
Figure : Autodesk Inventor model deflection analysis.
Figure 6-Hourly Temperature Readings, April 10
9
of the Sundrums was found to be about 80%, assuming no losses.
The ideal temperature that a water heater should be set at is 60 ̊ C (140 ̊ F) [7]. This was
determined based on the temperature of water which kills Legionella (the bacteria for
Legionnaire’s disease) and prevents scalding. The tank temperature at the end of the day (4PM)
was, on average, found to be 104 ̊ F. This value was at the end of a testing session when the
pump was left running overnight, leading to a low starting temperature in the tank the next
morning. The test was performed again, but instead of leaving the pump running continuously
the night before, it was turned off. As expected, the starting tank temperature the next morning
was much higher. This was due to the fact that the pump was not cycling the cooler nighttime
water into the tank. Subsequently, a higher tank temperature at the end of the day was recorded
(roughly 120 ̊ F) (Figure 6).
A secondary goal of the experiment was to observe if there was an increase in power
output for the panels with heat recovery units, as opposed to those without. The power output for
each panel was much lower than what was expected, based off of the calculations which were
performed when selecting a resistor (Appendix 2). The resistors which were used were of a
variable resistance, ranging from .3 Ω to 900 kΩ. The cut sheet value which was provided for the
resistor was 47 Ω, which was why it was selected. During test sessions, the actual resistance was
found to be about 130 Ω. This is why the power output per string was much lower than what was
expected.
10
DISCUSSION
The objective of this project was to design and build a mobile PV unit which will allow
for the testing and analysis of the heat recovery capabilities of the SunDrum system. Based off of
the analyzed data and results, methods of further increasing the heat recovery capabilities of the
SunDrum’s performance will be proposed.
From the Sundrum cut sheets, the thermal performance efficiency for a system which is
constantly running is approximately 57%. The number which was calculated experimentally was
approximately 80%. The difference in these values can be mainly attributed to assumption of no
frictional losses in the system. Another factor were the inaccuracies and assumptions which were
made in the solar and thermal calculations, which were idealized for simplicity and can greatly
alter the perceived efficiency.
Several data points were used to compare the SunDrum equipped panels to a standard PV
panel. The first of these data points was the power produced, which was used to determine how
well the panels were performing.
Due to a limited budget, the use of thermocouples, which would have provided a
continuous temperature reading of the panels’ surface, was replaced with an infrared
thermometer gun which was used periodically to measure the temperature of selected locations
on the panels’ surface. This, however, provided us with less data than continuous readings and
therefore limited the accuracy of data collection.
Due to time restraints, performance testing of individual panels and SunDrum units could
not be completed, which resulted in a non-well defined baseline to compare the two panel
strings. The use of six panels decreased the inaccuracy provided by the unknown individual
panel performance by limiting the impact of the variance.
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The panels that were donated by Bosch (Bosch Solar Energy, Erfurt, Germany) were not
compatible with SunDrum in terms of their surface area. The SunDrum units were designed to
cover the entire rear surface of a given PV panel to maximize the effective area of heat transfer.
The donated panels have a greater surface area than the SunDrum units. This limited the total
heat transfer, which reduced both the efficiency of the panel and the heat recovered.
The surface of the SunDrum unit is semi-reflective and light gray in color, which will not
absorb the maximum amount of solar radiation that penetrates the PV Panel, therefore failing to
maximize the amount of energy that can be collected. One proposition is to modify the surface of
the SunDrum to matte black which will absorb the maximum amount of solar radiation and
therefore achieve a higher surface temperature. The highest temperature the hot water tank can
achieve is approximately the temperature of the surface of the PV panels and SunDrum units,
therefore this modification could increase the maximum recorded tank temperature of 122
degrees Fahrenheit closer to the goal temperature for domestic use of 140 degrees Fahrenheit.
One concern about this method is that by changing the surface of the SunDrum another layer will
be added which will serve as resistance to the conductive heat transfer from the PV Panel to the
SunDrum.
Another modification that could be made to increase the maximum temperature of the
tank is to use PV panels which generate a higher current. Increased current results in greater heat
generation, which will maximize the temperature the panels will achieve. Although with or
without this modification the maximum temperature in the tank may not be sufficient for
domestic hot water use, this isn’t to say, however, that the hot water system which is
implemented could act as a supplement to an electric heater to save on energy costs.
12
The rate of increase in temperature in the tank can be improved by modifying the
plumbing connections. The current system connects the SunDrum units in series, which results in
an increase in temperature of the working fluid from the first SunDrum unit in the series to the
last. Heat transfer from the PV panel to the working fluid is proportional to the temperature
difference between the two, therefore the rate of heat transfer is compromised by the increasing
temperature of the working fluid throughout the system. If the plumbing was changed to parallel
flow this would maximize the rate of heat transfer to the hot water tank.
Weather conditions were not ideal for all testing sessions. The first testing session started
relatively clear, and progressively got cloudier as the day progressed, and the second test session
was very windy. The weather conditions for the remaining tests were favorable. The weather
patterns were reflected in the panel surface temperature, where on clear days, the surface panel
temperature was higher.
The optimal irradiance angle which was calculated early last semester during the design
phase was based on a projected testing time during the months of January to March. Due to
delays in completion of the electrical and plumbing systems, the first test did not take place until
the last week in March. Considering the design tilt angle did not correspond to the actual testing
month, non-ideal values were gathered.
Future classes may want to more accurately define a baseline of the panel’s performance
by performing individual panel tests so as to find how each panel functions without any type of
heat recovery unit. Not all panels will output the exact same power, collect the same amount of
heat, or run with the same surface temperature, so finding out these variables within the panels
will allow a better quantification of the SunDrum’s heat recovery capabilities. More accurate
13
data readings, in particular temperature measuring methods, should be implemented. These could
include the use of digital thermocouples on the rear panel surfaces, inside the tank, and even in
the water lines. A pyranometer could be implemented to measure the instantaneous solar
irradiance on the panel’s surface, allowing for an accurate reading of the panel’s power
producing capabilities. The tank could also be attached to the lower wooden base of the rig, to
allow increased ease of mobility.
The variable range resistors were found to be operating at a higher resistance than
designed for. They could be swapped for ones which would provide less resistance, and in turn,
allow for more power to be produced by the panels.
Any proposed modifications that are left incomplete should be implemented and tested,
and additional modifications to the SunDrum should be proposed. The main limitation of the
SunDrum’s heat recovery capabilities should also be addressed, by installing a heat recovery unit
that is sized properly for the chosen panels.
CONCLUSION
The purpose of this project was to design, build, and test a mobile PV rig which would
allow for the testing and analysis of the heat recovery capabilities of the SunDrum system and its
effects on PV panel efficiency. Based off the analyzed data and results, methods of further
increasing the panel efficiency and the amount of heat recovery were proposed.
After the completion of the semester’s testing sessions, it was apparent that the testing
structure and experimental setup which was designed worked as planned. The SunDrum heat
recovery units successfully removed enough heat from the photovoltaic panels to transfer the
14
energy to the hot water tank. Even though there was not a noticeable difference in panel
performance, the initial intent of the SunDrum was realized.
The heat recovery capabilities of this system in particular would likely not be sufficient
enough to provide enough heat in a domestic application. To successfully use the SunDrum in a
similar application, the aforementioned suggestions for improvement should be taken.
APPENDICIES
Appendix 1. Budget
According to the chart below, the project was within the estimated budget. Both material costs
and weekly labor costs were lower than what was projected. Other aspects of the budget,
including travel, equipment, subcontracting, and facilities, are zero; the project did not require
any of these costs. A contingency of 5% was set aside (out of a total available budget of $1750)
to plan for any non-forecasted expenses. The following budget analysis was performed.
15
Cumulative Cost by Week
$20,000.00
$18,000.00
$16,000.00
Costs ($)
$14,000.00
$12,000.00
Estimated Costs
$10,000.00
$8,000.00
Actual Labor Costs
$6,000.00
Earned Value (CEV)
$4,000.00
$2,000.00
$0.00
1
3
5
7
9
11 13 15 17 19 21 23 25 27 29
Week
Figure 7-Cost Analysis
1. Total Budgeted Cost was the available budget from the school of engineering, totaling
$1750.
2. The Budgeted Actual Cost (BAC) was calculated as what the project was thought to cost
in total, including materials and labor, totaling $18,323.032.
3. The Cumulative Budgeted Cost (CBC) was calculated as what the project was thought to
cost to the end of the fall semester. This was based off of the projected percentage of
completion and the weekly calculations performed for the BAC.
4. The Cumulative Actual Cost (CAC) was calculated as what actual funds were spent, with
respect to both materials and labor.
16
5. The Cumulative Earned Value (CEV) was calculated based off of the BAC, and the
estimated percentage of work which has been completed (1000%).
𝐶𝐸𝑉 = (𝑃𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑜𝑓 𝑊𝑜𝑟𝑘 𝐶𝑜𝑚𝑝𝑙𝑒𝑡𝑒𝑑) × (𝑇𝑜𝑡𝑎𝑙 𝐵𝑢𝑑𝑔𝑒𝑡)
𝐶𝐸𝑉 = (1) × ($18323.03) = $18323.03
6. The Cost Variance (CV) is the difference in the CAC and CBC.
𝐶𝑉 = 𝐶𝐴𝐶 − 𝐶𝐵𝐶
𝐶𝑉 = $18264.12 − $17233.95 = $1030.17
7. The Cost Performance Index (CPI) represents a ratio of what was both budgeted and
actually spent to this point. This is a value greater than one at the current point, as the
project is currently performing under the budget.
𝐶𝑃𝐼 =
𝐶𝐸𝑉 18264.12
=
= 1.060
𝐶𝐴𝐶 17233.95
8. The Forecasted Cost at Completion (FCAC) is a value which represents the total cost,
based off of the performance to date. The value below was based off of what was
completed at the end of last semester. This value was above what the actual cost (CAC)
was.
𝐹𝐶𝐴𝐶 =
𝑇𝐵𝐶 18,323.03
=
= $17,608.26
𝐶𝑃𝐼
1.041
17
Appendix 2. Calculations
The equation used for calculating the design power output for the testing rig was…
𝑃𝑜𝑤𝑒𝑟 (𝑃) =
𝑉2
𝑅
…where “V” is voltage and “R” is resistance. The voltage across three panels connected in series
is the sum of the individual panel’s voltage, and the resistance is the rated resistance provided by
the heat sink (47 ohms). Therefore, the design power for each string was found to be:
91.5 𝑉 2
𝑃𝑜𝑤𝑒𝑟 (𝑃) =
47 Ω
𝑷𝒐𝒘𝒆𝒓 (𝑷) = 𝟏𝟕𝟖 𝑾
The current which was flowing through the system (if the resistors were to provide 47 Ω of
resistance), was found to be:
𝐶𝑢𝑟𝑟𝑒𝑛𝑡 (𝐼) =
𝐶𝑢𝑟𝑟𝑒𝑛𝑡 (𝐼) =
𝑉
𝑅
91.5 𝑉
47 Ω
𝐶𝑢𝑟𝑟𝑒𝑛𝑡 (𝐼) = 1.95 𝐴
The efficiency of the SunDrums was calculated based on an approximate measure of solar
irradiance and the measured power output, as follows. It is worth noting that the provided
efficiency for the panels were based on ideal, constant standard temperature conditions. This
calculation was also performed on the basis that all power was not converted to electricity by the
panels was lost to heat. This is not true, but it provided a rough estimate of SunDrum and panel
performance.
𝐷𝑒𝑐𝑙𝑖𝑛𝑎𝑡𝑖𝑜𝑛 𝐴𝑛𝑔𝑙𝑒(𝛿) = 7.35°
18
𝐸𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝐴𝑛𝑔𝑙𝑒(𝛼) = 61.0541°
𝑍𝑒𝑛𝑖𝑡ℎ 𝐴𝑛𝑔𝑙𝑒(𝑧) = 28.9459°
𝑀𝑜𝑑𝑢𝑙𝑒 𝐴𝑛𝑔𝑙𝑒(𝛽) = 45°
𝐴𝑖𝑟 𝑀𝑎𝑠𝑠(𝐴𝑀) = 1.1421
𝑆𝑜𝑙𝑎𝑟 𝐼𝑛𝑡𝑒𝑛𝑠𝑖𝑡𝑦(𝑆𝐼) = 1.353(. 7) 𝐴𝑀
.678
= .9158
𝐾𝑊
𝑚2
𝑆𝑜𝑙𝑎𝑟 𝐼𝑟𝑟𝑎𝑑𝑖𝑎𝑛𝑐𝑒 𝑜𝑛 𝑀𝑜𝑑𝑢𝑙𝑒(𝑆𝑀) = 𝑆𝐼[cos(𝑧) sin(𝛽) + sin(𝑧) cos(𝛽)] = .88
𝐴𝑝𝑝𝑟𝑜𝑥𝑖𝑚𝑎𝑡𝑒 𝑆𝑜𝑙𝑎𝑟 𝐼𝑛𝑠𝑜𝑙𝑎𝑡𝑖𝑜𝑛 = (𝑆𝑀) (5
𝐾𝑊
𝑚2
ℎ𝑟
𝐾𝑊ℎ
) = 4.40 2
𝑑𝑎𝑦
𝑚 𝑑𝑎𝑦
𝐴𝑝𝑝𝑟𝑜𝑥𝑖𝑚𝑎𝑡𝑒 𝑃𝑜𝑤𝑒𝑟(𝑃) = (𝑆𝑜𝑙𝑎𝑟 𝐼𝑛𝑠𝑜𝑙𝑎𝑡𝑖𝑜𝑛)(𝑀𝑜𝑑𝑢𝑙𝑒 𝐴𝑟𝑒𝑎) = 6.358
𝐾𝑊ℎ
𝑑𝑎𝑦
From the cut sheets the approximate panel efficiency is 13% and the power increase due
to Sundrum from testing is 12.4%. The mass of water in the tank is 170 kilograms based off of
there being 45 gallons of water in the tank. The change in temperature of the tank was 40 degrees
Fahrenheit or 22.222 Kelvin.
𝐸𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙 𝑃𝑜𝑤𝑒𝑟 = (P)(Panel Efficiency)(1 + Sundrum Power Efficiency) =
𝑃𝑜𝑤𝑒𝑟 𝐶𝑜𝑛𝑣𝑒𝑟𝑡𝑒𝑑 𝑡𝑜 𝐻𝑒𝑎𝑡 = 𝑃 − 𝐸𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙 𝑃𝑜𝑤𝑒𝑟 = 5.436𝐾𝑊ℎ = 19570𝐾𝐽
𝑄𝑇𝑎𝑛𝑘 = 𝑚𝑤𝑎𝑡𝑒𝑟 𝑐𝑝 𝑤𝑎𝑡𝑒𝑟 ∆𝑇 = (170)(4.187)(311.483 − 289.261) = 15849𝐾𝐽
𝑆𝑢𝑛𝑑𝑟𝑢𝑚 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦(𝐸𝑥𝑝𝑒𝑟𝑖𝑚𝑒𝑛𝑡𝑎𝑙, 𝑁𝑜 𝐿𝑜𝑠𝑠𝑒𝑠) =
15849
= 80%
19570
19
20
Appendix 3. Electrical Schematic
21
Append
ix 4.
Gantt
Chart
22
REFERENCES
[1.] E. Cuci, et al., “Effects of passive cooling on performance of silicon photovoltaic cells”
International Journal of Low-Carbon Technologies, vol. 6, no. 3, pp. 299-308, September
2011.
[2.] M. J. O’Leary and L. D. Clements, “Thermal-electric performance analysis for actively
cooled, concentrating photovoltaic systems” Solar Energy, vol. 25, no. 5, pp. 401-406,
November 1979.
[3.] S. Zimmerman, et al., “A high-efficiency hybrid high-concentration photovoltaic system”
International Journal of Heat and Mass Transfer, vol. 89, pp. 514-521, October 2015.
[4.] W. J. C. Melis, S. K. Mallick, and P. Relf, "Increasing solar panel efficiency in a
sustainable manner," 2014 IEEE International Energy Conference (ENERGYCON), 1316 May 2014, Piscataway, NJ, USA, 2014, pp. 912-15.
[5.] R. Arshad, S. Tariq, M. U. Niaz, and M. Jamil, "Improvement in solar panel efficiency
using solar concentration by simple mirrors and by cooling," 2014 International
Conference on Robotics and Emerging Allied Technologies in Engineering (iCREATE),
22-24 April 2014, Piscataway, NJ, USA, 2014, pp. 292-5.
[6.] T. McLemore, H. Woolard, “Team Tidewater Virginia Integrated Solar Thermal
System,” July 2013.
[7.] B. Lévesque, M. Lavoie and J. Joly, "Residential Water Heater Temperature: 49 or 60
Degrees Celsius?", Canadian Journal of Infectious Diseases, vol. 15, no. 1, pp. 11-12,
2004.