PREPARED BY : MUHAMMAD HAFIZ IRFAN BIN SIDELI
PROGRAMME : BACHELOR OF ELECTRICAL AND ELECTRONICS ENGINEERING
STUDENT ID : 1700 6532
COURSE CODE : EDB30 63
LECTURER : IR DR MOHD FARIS B ABDULLAH
TOPIC : SOLAR PV SIZING
DATE OF SUBMISSION : 5 JULY 2019
Energy is one of the hot matters today. The energy industry currently shifting towards
switching from a typical or common source, fossil fuels to the renewable sources that are way
cleaner compare to the traditional fossil fuels, and it is becoming greater aggressive in the
international market. Electricity from solar is available at multi scales with many incentives,
simple and fast implementation processes. Photovoltaic s (PV) stre ngth is one of the most
promising rising technologies. PV system sizing includes the specified calculations of the
energy produced and suits with the preferred strength of current demand. The predominant
parameter that PV designers identify when designing a PV array is the load energy demand or
power utilization in (kWh). When describing a PV device in terms of components, it is logical
to use the power flow from the array aspect to the load side. However, when sizing a PV system,
need to think about the po wer demand first than thinking about the PV supply side. Thus, PV
device sizing starts at the load and proceeds backward to the PV array side.
A. To discuss the losses and benefits of solar systems.
B. To determine the PV sizing only on Module, Inver ter, and System Design with the
remaining parameters (Shading and Layout, Losses etc.) at default values.
For this assignment I will be focused on Dallas, Texas in United States of America (USA)
area . The reasons I choose Dallas, Texas USA is because in Dallas, the summers are hot and
muggy, the winters are cold and windy. Over the course of the year, the temperature typically
varies from 39°F to 96°Fand is rarely below 26°F or above 102°F. So, this is very good for me
to varies the difference an d understanding behavior of solar for a different situation and
weather. In this assignment also, i will explain more on what are the solar is all about and also
will be discussing on what are the things need to look out on designing the solar system for
residential purpose at Dallas, Texas USA . All the information like weather, shading, layout ,
losses and else will be taken from NRELs System Advisor Model (SAM). Lastly, I will
explain and suggest in terms of des ign aspect and technical performance from the result that I
get from SAM .
2.0 Solar Energy and Module
Solar energy is the technology used to harness the sun’s power and it is famous of for
generating an electricity or heating and desalinating water. When daylight hits the cells, the
electrons will loose from their atoms. As the electrons waft via the cell, they generate
electricity . Photovoltaics (PV) additionally called solar cells, are electronic mechan ism that
change sunlight immediately into electricity. They have been invented in 1954 at Bell
Telephone Laboratories in the United States. Today, the PV is one of the rapid rising renewable
energy technologies and is prepared to play a key position in the future global electrical energy .
Solar PV installations can be combined to supply electrical energy on an industrial scale
or organized in smaller configurations for mini -grids or personal use. Using solar PV to energy
mini -grids is an exceptional way to bring electricity access to humans who do no t live close to
power transmission lines, mainly in developing countries with incredible solar electricity
resources. The fee of manufacturing photovoltaic panels has plummeted dramatically in the
closing decade, making them no longer only affordable but often the most inexpensive shape
of electricity. Solar panels have a lifespan of roughly 30 years and come in range of shades
depending on the what categories of materials used in manufacturing.
The Solar Inverter is a basic system in any solar energy system. Its primary feature of the
inverter is to convert the Direct Current (DC) output of the photovoltaic panels into Alternating
Current (AC). The several electrical and electronic elements linke d in the circuit assist in the
transformation . This type of inverter aids in altering the DC into AC using from solar power.
In the situation of AC (alternative current) is the power that provide returned and out in internal
the circuit. Commonly , the AC i s used for household appliances. The rational why to use this
inverter as a prime to the everyday electric powered , then it is due to the fact the solar inverter
makes use of the solar energy which is accessible in adequate from the Sun is easy and also no
Inverters have evolved from much more than simply inverting the electrical currents of a
solar energy system . Inverters should continue to upgrade and deliver down cost, while keeping
its key qualities for a solar energy (reliability, effectivity & facets such as data monitoring) .
2.2 Solar System Design
On -grid solar systems are by away the common & generally used at residential and
businesses. This style does not need batteries and use usual solar inver ters and are connected
to the public electricity grid. Any extra solar power that you generate is exported to the
electrical energy grid and you will get paid a feed -in-tariff (FiT) or credit for the electricity you
An off -grid system is not conne cted to the electricity grid , so it requires battery storage.
An off -grid solar system has to be designed properly so that it will produce enough power
throughout the year and have enough battery capability to meet the homes necessities , even in
the winte r when there is less sun light. The price for off -grid systems are a whole lot more
expensive than on -grid systems because of batteries and inverter and usually use the off -grid
are remote areas because far from electricity grid. However, battery prices are decreasing
quickly , so there is now a growing market for off -grid solar battery constructions even in cities
RESULT AND DISCUSSION
All the result and details are from NRELs System Advisor Model (SAM).
3.1 Load -Usage
The table on the left shows the monthly electricity load
by an average home and the monthly AC system energy
produced by the solar PV system. The system AC
energy varies by month due to the four seasons in the
USA. As we can observe, the energy produced by Solar
PV system is not sufficient to fully provide for the
This system still requires an external power grid, also
known as Grid -Connected Systems, which what most
residential homes with Solar PV system ar e using.
Energy generation is at its peak April till July where its
summer in Dallas. We can observe a big drop in energy
generation during November when winter comes,
which has relatively low sunlight compared to summer.
Electricity load can be observed from the graph as the
highest load is used during summer time.
The graph on left s hows the monthly energy and load,
similar to the data used in the table on top. If we observe
the graph above, which shows the monthly energy and
load monthly, the hi ghest load consume is in July. As
we can see, the load graph sudden rise during summer.
This is may be cause of the hot weather, the user will
use more appliances such as air -conditioner to cool
them self. Because of that, the energy produces by our
solar system is not sufficient. In order to fix the
problem, user need to have a backup power and cannot
rely on solar system only.
The graph on the left shows the total percentage of
energy losses . As we can observe that losses from
AC inverter is the highest one this is maybe due to
the low irradiance levels, where the efficiency drops
It can be measured that sizing an inverter efficiently
for its required motive is important if it is undersized,
there will no longer enough sufficient power ,
demanding further than its limit will shut it off , if it
is oversized, it will be a great deal much less efficient
(due to standing losses).
Next, loss from the module. The loss from module
can be caused from a few reasons such as mismatch
of solar cells, resistance of ribbon and band gap
energy (If a photon has more energy than the
required amount, then the extra energy is lost).
On the left shows the losses that also need to look out
for the area at Dallas, Texas USA. Firstly, Soiling
losses. The Soiling losses refer to loss in power rising
from snow, dirt, dust and other particles that cowl the
top or surface of the PV module.
Next, DC and AC wiring. DC & AC wiring loss
consists of the resistive losses in the cables and wires
that used at some point of the entire PV plant from
the PV which includes the total route from the PV
module to the primary power grid.
3.3 Ratings Performance
Table on the left show the performance from the
modules and inverters. For the modules, the cell
material is monocrystalline and its from SunPower
SPR -X21 -335 model where it able to produce up to
334.2W for a module and if for 14 quan tity it can go
up to 4.69KW. For the inverter, the input range will
be n100 -480 VDC and will be able to produce total
capacity of 3.85kW AC , wh ere the ratio of DC to AC
Table on the left side show the Array table . Since we
have 14 modules, we can make it into 2 strings and
each string consists of 7 modules as rated on the table
above. For the losses in the array we need to focus
more on DC losses and soiling where this two will
give an effect to the array performance.
On the left side, we can see the table of performance
adjustment and graph of the annual energy
production. We can see that the graph is decreasing
year by year about 0.5%/year as stated in the table of
the performance adjustment.
The reasons of this happen is becaus e Crystalline
silicon modules placed in extreme climates showed
excessive degradation rates. For very cold climates,
panels subject ed to heavy wind & snow loads will
suffered the most.
On the other hand, panels in comparable climates
that were establish in a facade, removing the snow
load, had very little rates of degradation. At the other
extreme, panels in desert climates exhibited massive
drops in production over time close to 1% per year
basically due to excessive levels of UV exposure.
Panels in gre ater sensible climates such as the
northern United States had degradation rates as low
as 0.2% per year. Those panels should maintain 96%
of their manufacturing abilities after 20 years.
As a common solar enterprise rule of thumb, solar
panels last about 25 -30 years. However, this doesnt
imply that they end producing electricity after 25
years it just means that electricity production has
declined by way of what manufacturers consider to
be a tremendous amount.
On the left showed the table of annua l results (in
year). The Global Horizontal Irradiance (GHI) is the
full quantity of shortwave radiation obtained from
above through a surface horizontal to the ground.
This cost is of unique interest to photovoltaic
installations and consists of both Direc t Normal
Irradiance (DNI) & Diffuse Horizontal Irradiance
Solar irradiance on a PV panel in the Plan of Array
(POA) is a mixture of direct solar rays, diffuse
irradiance and albedo (irradiation reflected through
the ground).The direct irradiance on a panel or Plan
of Array (POA) is the irradiation coming directly
from the sun improved by the cosine of the angle of
incidence . GHI is decrease than POA and Irradiance.
It indicates the significance of putting the panel at the
most efficient angle or usin g trackers that comply
with the sun during the day.
Lastly, showed that performance ratio of the modules
based on annual results is 0.8. Where this is pretty
good, because as we know that the performance ratio
is a measure of a PV plant that defines the
relationship between the real and theoretical energy
outputs of the PV plant. The frequent PV system with
an excessive Efficiency can obtain a total
performance ratio over 70% and for solar module
that primarily based on crystalline cells can even
att ain an excellent factor of 0.85 to 0.95.
3.4 Electricity Bill With and Without System
As we discussed insufficient energy to supply our
load, we need a backup power source from electric
company in Dallas, Texas such as Reliant Energy .
When we used other supply from electric company,
we must pay electricity bill to that company. Graph on
the left shows, electricity bill with and without the
solar PV system. Below is a table of electric usage and
bill for each month with and without solar PV systems.
For the conclusion, the Solar PV system give so much advantages to the users especially
when it comes to electricity bills. It also processes energy quietly because it converts energy
directly without mechanical part. The system also can be in stall anywhere with expected life