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Implementation of Tilt angle computing in IoT Based PV System

Implementation of Tilt angle computing in IoT
Based PV System
Sivagami.P1, Meet Mehta1, Abhijeet Kumar1, Harikrishnan. R2, Pushpavalli.M1 and Abirami.P3
1Dept. of EEE, Sathyabama Institute Of Science &Technology, Chennai,India
2Symbiosis Institute Of Technology, Symbiosis International Deemed University, Pune,India
3Dept. of EEE, B. S. Abdur Rahman Crescent Institute of Science & Technology, Chennai,India
E-mail :,
Abstract- Because of depleting energy resources, to increase
the reliability as well to reduce the capital expenses
innovation has to be made to increase the power output from
renewable energy. In order to meet the energy demand in
future among the energy sources one of the propitious
energy source is solar energy. The energy from the sun is
abundant and is radiated on the earth surface in the form
of heat and light. Some of the alterable factors which
influence the production of electric power from solar energy
are PV installation factors namely the angle of incidence of
light from the sun, orientation, area of exposure etc. The
factors that cannot be altered are ambient temperature,
wind movements, solar insolation etc. Since the earth and
the sun position differs for the month and season. Due to this
PV panel tilt angle as well as absorption of sunlight vary.
Thus, the energy generation can be increased by
determining the optimum angle for PV panel to collect
maximum amount of solar energy to increase the electrical
energy generation. Thus, tilt angle decides the PV panel
surface area exposed to the solar radiations. If the yearly
average fixed tilt angle is used the loss of energy is around 8-
10% for each month. In order to increase the efficiency, the
tilt angle should be varied. This paper confers about the
factors influencing the tilt angle, determination of tilt angle
and and also about IoT-Internet of Things integrated smart
methodology for varying the value of tilt angle for PV panel
to extract maximum energy to make PV more efficient and
Keywords: Solar irradiation; Photovoltaic system-PV
system; tilt angle
One of the most widely used energies in producing
electricity is fossil fuels. But in recent years the
contribution made by non - fossil fuel gradually
increases. Because of depletion of fossil fuels the
consumption will decay by time but solar energy is
renewable and it depends on the sun that is it will not
vanish or run out like fossil fuel. Fossil fuel causes
land degradation, water pollution, emits harmful
gases. The emission of harmful gases like carbon
dioxide causes increase in temperature which results
in global warming but solar produces clean energy.
The cost of energy produced using fossil fuel is
expensive when compared to energy produced using
solar. In conventional fossil fuel forecast fossil fuel
energy consumption increases till 2020 after that its
consumption decreases. The power produced using
fossil fuel cost around .05$/kwh whereas solar cost
around 0.029$/kwh. The implementation of solar
photovoltaic system helps in producing electric
power. The electric power produced can be sold that
is it provides an income for the investor or owner of
the solar plant. Since it helps in earning it is
important in economic point of view. Thus, solar
photovoltaic system gains importance in this era not
only because of energy point of view but also
economic point of view. The figure 1 represents the
conventional fossil fuel rise and fall for the period of
1900-2100. The figure 2 delineates the contribution
of fossil fuel for the year 2018-2020. It becomes
essential to harness maximum yield from solar.
Solar power generation is dependent on
environmental parameters namely solar insolation,
ambient temperature, temperature of the PV panel,
speed and direction of wind, tilt angle etc. Tilt angle
also play a vital role in harnessing maximum energy
from PV panel. There are different methodologies
available to determine the tilt angle. They are using
direct, diffuse and reflection components of radiation
or by involving components either dependent or
independent on atmospheric condition namely
isotropic and anisotropic. In IDR- Isotropic Diffused
Radiation model diffused radiation intensity of sky is
assumed to be uniform [11]. In NADR- Anisotropic
Diffused Radiation model for tilted surface it
includes circum solar diffused radiation and horizon
brightening component [12]. PV calculator
determines the output power from PV panel by
varying the value of tilt angle. The equation for
optimal angle is based on latitude [13]. Manually tilt
2022 International Conference on Advances in Computing, Communication and Applied Informatics (ACCAI) | 978-1-6654-9529-5/22/$31.00 ©2022 IEEE | DOI: 10.1109/ACCAI53970.2022.9752532
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angle is adjusted. The power output is determined for
various tilt angles [14]. MAT lab code also helps us
in determine the tilt angle based influenced by solar
radiation [15]. Some of the papers here discussed
about the methodology in calculating the tilt angle
and few other papers here delineate the importance of
tilt angle for harnessing maximum energy.
The energy generation increased by 10.54% for
latitude of 41°and longitude of 20° for Barcelonia
city in Spain. In winter it has 56.4°, for spring season
it is found to be 29.11°, summer 13.76° and for
autumn 48.14° [1]. By examining the factors namely
latitude, solar insolation, covering areas, the optimal
tilt angle is determined for rooftop PV installed at
Jilin Electric power Research Institute and is found
that tile mode improves the power generation for
fixed area [2]. For winter season PV module with
higher tilt angle harness maximum energy and
reduces the cost by 25% when compared to that of
the traditional approach [3]. The optimum tilt angle is
used to determine the gain in terms of power output
and current intensity [4]. C programming
implemented to determine the yearly average tilt
angle [5]. The output obtained from thermal energy
conversion increases when solar thermal collectors
tilted at 40°. The result determined by considering
sunny day, cloudy day and an interemediate between
sunny and cloudy day that is for 3 different types of
days [6]. In main cities of Palestinian, solar panels
installed yielded 17% more power when angle
adjusted monthly. For seasonal and semiannual
adjustment, it generates 15% more. The yearly
average angle which yields 10% more is 29° for
Palestinian cities [7]. Particle Swarm Optimization
estimator developed to determine the value of tilt
angle to get maximum solar energy. The optimized
angle value determined using this method is
validated with analytical results and the outcome of
this method is found to be satisfactory [8]. Different
angle values are determined using regression analysis
for various months. For Jan-March the angle value is
found to be 32°, April-June it is 25°, July -September
its value is low and is 15° and for October-November
again it increases and is 37°, for the panels laced. in
Chandigarh location [9]. The voltage profile
determined for varying tilt angles and found that
34.5° yields maximum power for rooftop solar panels
in Belgium [10].
Fig. 1 Forecast of conventional fossil fuel
consumption []
Fig. 2 Contribution of fossil fuel and non- fossil
Solar radiation means solar power from sun received
per unit area in the form of electromagnetic radiation
in (W/m2), whereas integration of solar radiation for
a given time period is solar irradiation and it is given
in kWh/m2 or J/m2. The figure 3 delineates the
increase in radiation from 6 am and reaches peak at and gradually decreases from 12pm to 6pm
and also solar radiation and irradiation. Solar
irradiation may be direct horizontal, diffusion
horizontal, global horizontal or global tilted. If the
radiation moves through the atmosphere without
being scattered, reflected or absorbed by particles in
air is direct horizontal whereas the inverse of it is
diffusion horizontal. Global horizontal is the sum of
direct and diffusion radiation received from sun by a
horizontal surface and is denoted by SH. Global
horizontal irradiation differs for each location. Global
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tilted irradiation received by tilted surface from sun
is the contibution of direct and diffused radiation and
is represented as Sm. Sm mean the total number of
hours the panel is exposed to solar radiation. It is
expressed in term of SH, alpha and beta. Alpha(α)
represents the angle between ground level and
incident rays whereas beta(β) is the angle obtained
between the solar panel and horizontal plane.
Fig. 3 Variation in solar radiation received during
The number of solar hours determine the electric
power generation. If the number of solar hours is
more then, the power generated is also more. PV
panel has to be adjusted to particular tilt angle value
to harness maximum output. Tilt angle is influenced
by declination angle(δ) and elevation angle(α). When
the earth is moving it tilts with an angle, this angle
between earth axis and universe axis is called
declination angle. As the earth rotates the declination
angle changes that is the universe axis is constant but
the earth axis varies. When the earth axis is exactly
aligned with universe axis the declination angle is
zero. Zero declination angle causes spring climate on
the earth. During this period day hours equals night
hours. This happens exactly on 21st of march. When
the earth moves around and makes a quarter cycle the
declination angle increases in step from zero to its
maximum value 23.5 degree exactly on 21st of July.
During this period day hours is greater than night
hours and it causes summer on earth. When the earth
completes half cycle the declination angle starts to
decrease until it reaches zero. At this position again
angle becomes zero and the earth experiences
autumn climate. It reaches zero on 21st of
September. Again, when earth rotates for new quarter
cycle the declination angle again increases from zero
to 23.5 degree in opposite direction so its value
become negative that is -23.5 degree on 21st
December where night hours is more compared to
that of day hours. So, the earth’s surface become cold
during the winter season. During new quarter cycle
again, the angle decreases from maximum to zero as
a result the spring season starts and the cycle repeats.
Hence the declination angle may have the values [-
23.5,23.5]. The figure 4 shows the outpower yield for
declination angle.
Declination angle is determined using following
= 23.5 Sin( (284 )) 1
365 d
Where d delineates the day number of the year. For
example, let us consider the 12th day of February.
For this corresponding date the day no of the year is
43 therefore the value of d is 43. Substituting the
value in the expression declination angle is
determined. The figure 5 shows the day number for
the corresponding month in a year.
= 23.5 Sin( (284 43)) 2
( 14.29 )
Fig. 4 Influence of declination angle on output
Elevation angle values varies between to 90° and
is given by the expression
α=90°-ψ+δ 3
Where Ψ represents the latitude of the location.
The tilt angle β is determined using the expression
β=90-α 4
Some standard values of β are 15°, 20°, 25°,
30°,45°, 60°.
An excel program designed to calculate the peak sun
hours and tilt angle required to harvest maximum
energy. The steps involved in it are as follows.
Step 1:Getting the information about latitude and
longitude of the location where solar panel has to be
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Step 2: Getting the tilt angle beta.
Step 3: Getting peak sun hour value.
Since we know that Sm dependable parameters.
If Sm(max)- Sm(min)> 2 hours then Sm= Sm(min)
else Sm= ∑ Sm/12.
The data about insolation incident on a Horizontal
Surface (kW-hr/m^2/day) is obtained from the
website The power
access viewer helps in providing the value of SH for
any latitude and longitude. The figure 6 shows the
steps involved in getting value of SH. By selecting
particular location and for different time period solar
insolation on a horizontal surface can be
downloaded as ASCII, CSV, GeoJSON, NetCDF
file format. Once determined the value from the
website substitute that in excel program to determine
the value of tilt angle. The figure 7 represents the
data received in CSV format from the website. The
figure 8 shows the solar insolation value from 2000-
2019. The figure 9 shows the solar insolation level
for the period of December to February.
Accordingly, the optimal angle is calculated using
the excel sheet and is found that for Chennai
location in India the tilt angle is 30°and 15°. The
figure 10 shows the tilt angle for various months.
Fig. 5 Day number for a month in a year
Theoretically determined value is validated by
PVSOL simulation software. Tilt angle calculation
dated 4th March 2021 (63rd day as per the above
Substituting 63 in place of d as day number, we get,
after calculating, Value of declination angle (δ) as -
7.16° Elevation angle (α) = 90-ψ + δ ; where ψ is
latitude of the Semmancheri ( Chennai) (i.e. 13°).α =
Tilt angle β = 90- α = 20.91°
The figure 12and 13 shows the mean capacity,
monthly capacity factor and data set respectively.
After the Above case study for solar irradiation and
power generation using the total available sunshine
hours in Chennai. We have plotted graphs and
calculated the desired tilt angle for obtaining
maximum output from an installed capacity of 1.2
KW solar. By analysing tilt angle for the
abovementioned system as 21.5 degrees, we have
found that the generating capacity is at peak during
the months of November, December, January,
February, March and April by constituting about
65% of generation in this 6 month.
Fig. 6 Delineates the step to get the value of SH
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In order to optimize the PV output, the solar panel
must face the sunlight directly. The optimized PV
output for the year round is obtained by tilting the
panel at that particular location latitude. Tilt angle
information can be stored in the cloud portal.
According to the seasonal variations this information
is processed and stepper motor can be used to vary
the value of the tilt angle of the panel to harness
maximum yield.
Fig. 7 Website provided data in CSV format
The proffered PV farm automation installation using
cloud approach provides monitoring as well as
controlling over the internet securely from any place
without the need of hardware, large memory. Smart
PV system can be established with cloud setup. The
cloud provides lots of services. It provides large
memory for storing data. The stored data can be
processed and retrieved for analysis from the cloud.
In this system cloud processed data sends a
command to controller unit to perform the action
using Wi-Fi. The figure 14 delineates smart control.
Fig. 8 Solar insolation value for Chennai location for
period from 2000-2019
Fig. 9 Solar insolation value for Chennai location for
period from dec 2019-Feb 2020
Fig. 10 Tilt angle for Chennai location.
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Fig. 11 Delineating daily mean and monthly
capacity factor
Fig. 12 Delineating dataset
Fig. 13 Web based tilt angle adjustment using
stepper motor
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Fig. 14 Excel program showing the tilt angle
calculated for the month of march
Tilt angle value differs for each month when
calculated using the excel program. It was found that
for the month of December-36°, January-34° and for
the month of February- 27°. Therefore, for values
less than 22° the angle opted is 15° and for 22° - 36°
the angle opted is 30°. Similarly, for greater than 36°
and less than 52° the angle opted is 45° and for
greater than 52° the optimal tilt angle value is 60°.
For collection of maximum radiation for energy
conversion from the sun optimal tilt angle for each
month can be considered.The tilt angle Dec-Feb is
30°, March-September is 15° and for October-
November is 30° for Chennai location in India. The
yearly average tilt angle for the panel is 21.5°. The
tilt angle is made fixed in some cases to keep the
manufacturing and installation cost low. For
enhanced efficiency if tilt angle is not varied for
month at the least it has to be varied for seasons. As
extension of this methodology, IoT integrated
tracking systems that adjusts automatically the tilt
angle if implemented increases the power output and
also improves the efficiency. Thus, IoT implemented
renewable energy sector becomes smarter, more
efficient in improving the performance, reliability
and in extracting & distributing maximum energy
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Full-text available
Solar thermal collectors are usually installed at a fixed tilt angle. In the design stage of the solar thermal systems, the optimal value of the tilt angle is numerically evaluated according to the latitude and the climate of the location, aiming to maximize the yearly received solar energy and thus the yearly thermal energy output. To experimentally evaluate the influence of the tilt angle on the thermal energy output of the solar thermal collectors, a complex research infrastructure was developed in the Renewable Energy Systems and Recycling (RESREC) Research Centre of the Transilvania University of Brasov, Romania, consisting of nine solar thermal systems with flat plate and evacuated tubes solar thermal collectors. The solar thermal collectors were installed at tilt angles ranging between 0° and 90° on the rooftops of nine buildings in the R&D Institute to evaluate in the same time their performances under the continental temperate climate conditions of Brasov city (45.65°N, 25.59°E). The experimental results obtained in three types of days (sunny, intermediate and cloudy) are comparatively presented in the paper. The influence of the tilt angle on the thermal energy output of each type of solar thermal collector is discussed during the three types of days. Thus, the maximum thermal energy output was obtained in the case of the solar collectors tilted at 40°. Differences up to 10° … 15° of this angle did not significantly affect the output, only the extreme values of the tilt angle (0° and 90°) showed negative influence.
Full-text available
The optimum tilt angle of solar panels or collectors is crucial when determining parameters that affect the performance of those panels. A mathematical model is used for determining the optimum tilt angle and for calculating the solar radiation on a south-facing surface on a daily, monthly, seasonal, semi-annual, and annual basis. Photovoltaic Geographical Information System (PVGIS) and Photovoltaic Software (PVWatts) is developed by the NREL (US National Renewable Energy Laboratory) are also used to calculate the optimum monthly, seasonal, semi-annual, and annual tilt angles and to compare these results with the results obtained from the mathematical model. The results are very similar. PVGIS and PVWatts are used to estimate the solar radiation on south-facing surfaces with different tilt angles. A case study of a mono-crystalline module with 5 kWP of peak power is used to find out the amount of increased energy (gains) obtained by adjusting the Photovoltaic (PV) tilt angles based on yearly, semi-annual, seasonal, and monthly tilt angles. The results show that monthly adjustments of the solar panels in the main Palestinian cities can generate about 17% more solar energy than the case of solar panels fixed on a horizontal surface. Seasonal and semi-annual adjustments can generate about 15% more energy (i.e., it is worth changing the solar panels 12 times a year (monthly) or at least 2 times a year (semi-annually). The yearly optimum tilt angle for most Palestinian cities is about 29 • , which yields an increase of about 10% energy gain compared to a solar panel fixed on a horizontal surface.
Full-text available
Solar energy is one of the promising renewable energy sources which has the potential to meet the future energy demand around the world. To maximize the irradiance fall, solar panels are generally equipped with a motor tracking system and are placed at a specific tilt angle. However, tracking methods are not cost‐effective and a fixed tilt angle is not productive. This study proposes a method for harnessing maximum output from photovoltaic (PV) panels throughout the year by determining the optimal tilt angle. The investigation is performed on real‐time solar PV panels of 5 kWp rated capacity installed at 10°, 20°, 25°, 30°, and 40° angle on the rooftop of engineering institute situated at Chandigarh, India. The real‐time power generation response for a year is used to find the optimal tilt angle. The results obtained from the practical setup are validated by comparing it with the simulation results of the regression analysis. In addition, the impact of the optimal angle on total power generation and carbon emissions is analyzed. The results reveal that the proposed approach is quite effective to increase the power generation of PV panels up to 7–8% and can be practically implemented in any location throughout the world.
Full-text available
In Belgium, and many other countries, rooftop solar panels are becoming a ubiquitous form of decentralised energy production. The increasing share of these distributed installations however imposes many challenges on the operators of the low-voltage distribution grid. They must keep the voltage levels and voltage balance on their grids in check and are often regulatory required to provide sufficient reception capacity for new power producing installations. By placing solar panels in different inclinations and azimuth angles, power production profiles can possibly be shifted to align more with residential power consumption profiles. In this article, it is investigated if the orientation of solar panels can have a mitigating impact on the integration problems on residential low voltage distribution grids. An improved simulation model of a solar panel installation is constructed, which is used to simulate the impact on a residential distribution grid. To stay as close to real-life conditions as possible, real irradiation data and a model of an existing grid are used. Both the developed model as the results on grid impact are evaluated.
This article reports the investigation for the average optimal tiltangle of solar panels on a monthly basis (single axis tracking) for awide range of latitudes in the northern hemisphere to collect maximumtotal solar irradiation. Based on experimentally validated modeling, anew set of empirical relations has been proposed to compute the op -timum tilt angle on a monthly basis for the entire year. The accuracyof equations set is evaluated by standard statistical measures. Theproposed set of empirical equations is compared with an existing set ofempirical equations on various cities within the latitude and has yield -ed significantly better results. Solar Advisory Model (SAM) has beenused to compare—with respect to a fixed Solar Photo Voltaic (SPV)panel—the electricity predicted by (1) a new set of manual solar track-ing equations, (2) an established set of solar tracking equations, and (3)data from an automated single axis tracking system by a ProgrammableLogic Controller or PLC. It is found that, the manual tracking systembased on the proposed set of equations generates an annual averageincrease in electrical energy of (5-8)%, the old set of equation yieldsannual increase of (2-4)% and the PLC automated single axis trackingsystem generates a growth of (8-15)% over fixed SPV modules. Basedon the proposed empirical set of equation, a manual tracking systemhas also been designed and commissioned to reaffirm the justificationof the proposed equation set.
Maximization of the incident energy at surfaces of the photovoltaic modules is among the key factors of energy extraction maximization. In this paper, fixed tilt solar-PV systems are considered. The incident solar energy maximization problem is formulated as the maximization of the solar energy incident on the flat surfaces of the traditional flat solar-PV modules. Therefore, the presented study is not applicable to the curved solar-PV modules. The monthly, seasonally, semi-annually, and annually fixed tilt alternatives have been tested, then the optimal alternative has been selected. The Sahara middle (Adrar) district is considered as a representative site at the Algerian Big South as the long-term meteorological data are available from the ground meteorological station there. In comparison with the horizontally placed solar-PV modules, it is found that the incident solar energy increased by 20.61% for monthly, 19.58% for seasonal, 19.24% for semi-annual, and 13.78% for yearly adjustments. The results obtained with the ground measurements are compared with satellite measurements. It is found that the semi-annual adjustments in the tilt, which is estimated at 3.50° for the warm period (April-September) and 49.20° for the cold period (October-March) is the optimal compromise choice for the selected region.