Hello DIYers!
In setting up our DIY off grid solar
power,
We will be needing five components.
First, is the solar panel to generate the power.
Second, is the charge controller to charge our battery.
Battery to store the energy.
Inverter to convert the DC
to AC power.
And a lot of questions after questions after questions.
To start our off grid setup, let us first
go to the part one: ASSESS YOUR SITUATION
In assessing your situation, we need to know
first our power consumption.
Thus, will base the size
of our solar setup.
To measure our power consumption,
we will be needing a wattmeter.
A wattmeter has two functions.
First, power consumption at a given moment.
Take this as an example.
an electric fan and a television
We can measure their power consumption
the moment we plug them because they
have continuous power consumption while turned on.
Second function
of the wattmeter is power
consumption overtime. There are some devices
that are sometimes turned on and then off
and not working all the time eg. is a refrigerator.
Once it is turned on, it is not really turned on all the time.
When it is cold,
it will automatically turns off.
We need to measure its
consumption overtime for one day
or for 24 hours.
That is for the part one: to ASSESS YOUR SITUATION.
I will show you a video sample in my household.
Let us start with the laptop.
Guys, this is a typical consumption of our laptop.
When it is on its full load,
it ranges from 40 to 54
watts.
That's the typical consumption of our laptop.
Why do we use laptop at home?
Because my wife is an online teacher and if you want
to know how to be an online teacher, comment down below.
And for our DC fan, as you can see
it ranges from 17 to 18 watts.
Look at our DC fan.
This is my DC fan as you can see, I am using an adaptor.
I will also made a video on how to make a DC fan.
This is the consumption of our DC fan.
17.5 watts
We always use this fan all throughout the day.
And for our router, it ranges
from 6.5 to 6.6 watts.
Our router has low power consumption.
Can you see that?
click the
i button
for your to know this one
this is a DIY UPS
made by DIY PINOY
We still have one more load to include in our computation
for our power consumption but we will not be using
the wattmeter to measure it because I know that it is 9W.
You already saw our appliances
that is running at home
that will consume the power from the sun.
Laptop = 52 W
times 8 hours because we are using it for 8 hours
for a total of *416WH
DC fan = 17.5 W
time 24 hours because we use it for 24 hours
router = 6.6 W and we use it
for 24 hours and the LED light = 9W
time 16 hours and when we add them all
that will be our the daily power consumption
which is
1138.4 WH
so this
this is what we needed to know first
our daily power consumption
Let us go to our PART 2: SIZING YOUR INVERTER
We use inverter
to convert DC to AC power.
the power that we use at home is
AC the 220 V
the output in our solar is either
12V or 24V (DC) system and we will convert it
and we will convert it to
220V AC using an inverter
There are two types of inverter: Toroidal Inverter
and this is is the normal
inverter that is used in electronic devices like
TV, charger
1000W
there
How to know the size of the inverter that we will use?
for example
we have an electric fan, laptop and TV
let us compute their power consumption
at the same time
our AC electric fan
is 60W and the laptop is 50W
and 55W
television so if we add
them all, it's 165W
so that is the simultaneous power that we use
so if we have this 1000W
inverter, it can support our setup
we only consume 165W compared to our 1000W inverter
even if we consume 500W, it will still work
it can support our setup
let us now compare with a high power
consuming appliances like rice cooker
and washing machine
rice cooker consumes about
500W
once you plug it, it consumes 500 W
if you're using a washing machine, it consumes  550W
If we add them, the total power is
1050W
so our inverter will not work
the best inverter to use
is this 2000W inverter
because it is better to use a toroidal inverter in
motorized devices like washing machine
Let us now move on to the PART 3
SIZING YOUR SOLAR PANEL
To recap, we already know our daily power consumption
and we already know the size of inverter to use.
For our part three, we will size our solar panel.
In sizing our solar panel, we will be introduced
with the term "SUN HOURS".
Sun hours is the effective
number of hours that we can maximize the
power from the sun.
In the Philippines, we have a range of 4.5 to
5.5 sun hours. If you are in Metro Manila
you get 5 sun hours.
It's a good thing that we know sun hours
so that we have a basis
for the output of our solar panel.
Let us say that we have
100W solar panel.
In Metro Manila we have
5 hours or 5 sun hours,
if we will compute,
the possible output of 100W solar panel
is 500WH because we will multiply it by 5 that
is the effective output of the solar panel the whole day
5 sun hours so 500WH is the output
the is the ideal output of the 100W
solar panel
If you remember our daily
need is 1138.4WH
one 100W
solar panel is not enough
let us use three solar panel = 300W
times five is 1500WH
now our solar panel can
supply the 1138.4WH that we need
So, in sizing your solar panel,
we always base in our load
or to our daily power need.
solar output should be more than what we need
okay?
In solar panel sizing,
we are introduced with the rule number one.
"You can only spend what you make."
So whatever power your solar panel produced
that is the only power you can consume. No more extra power.
Unlike when you are connected to Meralco,
you can use unlimited electricity.
In this setup, you can only spend what you make.
If you produced 1000W,
that's the only power you can consume.
You can lessen your appliance's usage
if sun power production is low.
Let us now move to the PART FOUR: SIZING YOUR BATTERY BANK
In this part, we will learn new rules.
rule number 2 and rule number 3
In rule number two, you can save so much.
so you can only save what your battery capacity is
capable of
rule number three is "YOU CAN NEVER SPEND ALL
THAT YOU SAVE", we will further discuss this later
There are two types of batteries available in the market.
First is the deep cycle battery,
just like this for example
200ah battery 12V.
Second example is car battery.
MOTOLITE
What we use in solar is
deep cycle battery.
we do not use car battery
technically, it will work
but we do not use it. WHY?
Because its purpose and design
to produce massive energy at a short time
and charge slowly.
When turning on a car engine, we only use
massive power once to start the engine starter.
That starter is connected to the car battery.
And it charges slowly while we use the car.
Unlike in a deep cycle battery,
its purpose is lower amount of energy
over longer time and it charges quickly.
When we use it in our setup,
our power consumption
is not massive.
Our purpose is to use it for longer time
and to charge it quickly.
If you will save more in using a car battery,
-because it will still work with our solar panel-
it may break in a short period of time. Good bye money.
It is better to use a deep cycle battery.
There is another type of battery - Lithium
which is more expensive but is great
because we can use it for a long time
compared to the sealed lead acid like this one.
SIZING YOUR BATTERY BANK
Let us recall our daily power need
that we compute earlier
which is 1138.4WH
we will base here
for the size of our battery bank just like on
how we determine the perfect size of our solar panel
1138.4WH
divided by 12V
because our battery is 12V
it's okay if you will be using 24V
but our example here is 12V
so let's use 12V
1138.4WH
divided by 12V is equal
to 94.9AH
it became AH
because WH
we produce W
voltage times
voltage times amperes
is watts
since we have voltage here
cancel out the voltage, what remains is the AH
94.9AH
or 100AH *round up*
We cannot buy a 94.9 AH
let us choose a 100AH.
If you still remember rule number three,
"YOU CAN NEVER SPEND ALL THAT YOU SAVE''
because in this battery
we should never discharge below
50%
Why?
because
When we discharge lead acid
below 50%, its life is lessen.
The charging cycle is lessen.
When we discharge this battery,
battery life is lessen.
Instead of using it for a long time, it is lessen.
So if we have 100AH
what we need is
1138WH
we will not be using it in 100 hours
let us multiply it by two
so that we will meet our requirement
1138WH
Our usable power is
200AH times 12V is 2400
watt hours
we can only use 50% so we divide it by 2
1200WH
so now we meet our requirement
which is 1138
our battery can now store enough
power that we need daily
PART FIVE: WIRING YOUR SOLAR PANEL
rule number four
another rule introduced
solar panel to battery should be as close as possible
why?
because of what we call "wire resistance"
in wire resistance, there is a voltage drop
the longer the wire run, the more energy is
due to resistance
the longer the wire
we experience voltage drop
because the wire has resistance -it is not 100%
conductor
it also has internal resistance that's why there is a
voltage drop
There are two ways to
wire our solar panel.
parallel
for example
we have 100W solar panel
then notice the voltage
at Pmax is 18.55V
current at Pmax(Imp) is 5.36A
when we multiply them
it is equal to 99.43W
our example is three of 100W solar panel
if we connect them in parallel,
what will happen is
in parallel connection, current is added
as you notice the voltage is 18.55
it's the same
times 16.08A current
instead of
5.36
when we multiply them, it's 298.3 W
we sum up the current
second way is series
If we will connect 3 100W panels in series
what will happen is that the voltage
will be added
18.55 + 18.55 + 18.55
is 55.65V
times 5.36A current
equal to 298.3W
it doesn't matter
if the connection is in series or parallel
because we will be getting the same output of 300W
Let us look at this illustration.
if parallel
if our connection will be in parallel,
look at the left side
we have a single positive
and single negative line
all the positive and negative will be connected
from each of the solar panels
in series connection, it is single wired
then the positive
of solar panel one is connected to the negative
of solar panel two and the positive of solar panel two
is connected to negative of solar panel three
and so on
Why do we need to choose between series and parallel?
As what is stated in rule number four,
solar panel and battery should be as close
as possible because we have a voltage drop
let us calculate that voltage drop
for example we have
10 meters distance from
solar panel to battery
our cable size is 12
AWG or 12 gauge
if you want to be in depth in
wire sizing, comment down below
and let's talk about that in the next videos
let us talk about wire sizes because it has effects
let us take this as an example, let us say that
we have 12AWG with same distance of 10 meters
look at the voltage drop in the
parallel connection
it is equivalent to 9%
our voltage drop is 1.68
if we have
18.55 voltage from the solar panel
when it reach the charge controller
or the battery, what remains is 16.87
because of the voltage drop
that is caused by the distance of the solar panel
to the charge controller or battery
unlike in series
the voltage drop is 1% only
if your solar panel is connected in series,
and we get 55.65V
we only had 1% drop so
the
voltage that the charge controller will receive is 55.09
it's almost the same with the output
only a minimum voltage drop
this principle
in series connection, if the voltage is high
if we are transmitting a high voltage
the lesser the voltage drop and that is the same
principle
in power transmission
of power distributor like Meralco
notice their high voltage wire
they're using
transformer to convert
energy to kilovolts
then they use a transformer to step down
energy to each household
imagine the distance of the source of power
to every household
there will be a huge voltage drop
so to compensate that huge voltage drop
there are two options, to increase the voltage transmit
or increase the size of your cable
the wire that you will be using
of course if you will be increasing the size of the wire
you will spend more money
because it is more expensive
so you have to consider it in sizing your
solar power setup -the distance
how far is it?
what is the best to use?
series connection or parallel?
if plan to have single panel setup
you don't need to think about such
if you have a small setup
part six
part six: SOLAR CHARGE CONTROLLER
Its purpose is to control charging of battery
basically a sophisticated regulator
because we cannot connect
the solar panel
to the battery directly
it might get damaged
our solar panel's output
if you notice
is not only 12V -it is even higher
so that we can charge the battery
the source should be higher
what controls the
charging of the battery is the charge controller
there are two type of
solar charge controller
first, PWM
charge controller or
pulse width modulation
this is an example
that one is cheap
it has 80% efficiency
12V or 24V system 30A
10 or 20 amp common
common model and then
what's good with this is that it's cheap and you can buy
this charge controller for only 400php (8USD)
another type is the MPPT
or maximum power point tracker
this is an example SRLE
this is a beautiful item
they say that this can reach upto 98% efficiency
it's much much higher compared with the PWM
can handle 12V up to 100V depending on model
so if we will connect panel
in series, we cannot use PWN because
it can only handle up to 24V
you should use MPPT charge controller
is you plan to connect your panels in series
because it can handle higher voltage
compared to PWM
however, MPPT's drawback is
it is not that cheap -it is expensive
if PWM is 400php (8USD), MPPT is 4000php (80USD)
you need to consider that as well in you setup plan
what you will be using
if you will be using a single panel, PWM is okay
if you will use a single panel, do not use a MPPT
but if your setup is multiple panel or
a bigger setup, use MPPT
or if the distance is near
PWM is okay
those are the two type of charge controller
PWM and MPPT
SOLAR CHARGE CONTROLLER
SIMPLE EFFICIENCY COMPARISON
in PWM
let us use a parallel connection as an example
once the sun rises let us say at 7 am
our solar panel will produce
a voltage let us say 4V because
the sun just came out
in a parallel connection
the voltage is the same
output will also be the same
although current increased
however, if your current increased
and your voltage is 4V, your PWM charge
controller will not start charging because
our output is only 4V
it has a minimum voltage requirement
for it to start charging the battery
comparing it to the MPPT SCC
we can have a series connection in MPPT
because it can handle even higher voltage
when the sun rises at 7am
each of the panels produces 4V
and we have a series connection
what will happen? voltage will be added
now, we have 12V so that moment
the sun rises at 7 am, our MPPT
charge controller
starts charging our battery
compared to the PWM
it will wait for the panel to produce 12V
10 or 11V before it starts charging our batteries
unlike with MPPT
once it has enough voltage
from the panel
it will start charging the battery
we can obviously see the difference
with the charge controller's efficiency
let us now move on to part seven which is SOLAR SAFETY
using fuse, breaker, automatic
or manual disconnect and grounding
so from solar panel
going to MPPT solar charge controller
the output current that we will measure
is 15.87A if we are in a series connection
if you can still recall with series and parallel connection
in designing fuse and breaker
we should be using a higher value
let us say 20A
20A fuse or breaker
in that wire there
shouldn't be 20A flowing
because our expected is 15.87A only
from MPPT
solar charge controller to battery
we can observe the same current
because that is our input
so we can use the same fuse or breaker
battery going to inverter
the sizing that we compute earlier depending on the appliances that we will be using
let us say 500W
if you have a 500W inverter
we can
put a manual disconnect
from battery to inverter
for safety purposes
we can easily disconnect the connection of battery and inverter
so the output current that we can get
from battery to
to inverter is 40A so 500W
divided by 12
is 40A so we can use a 50A
fuse or breaker
because it should be higher and
it shouldn't increase for more than 50
so base on our calculations
DIYers
for 1kW solar solar off grid setup
our daily
load of 1138.4WH
and this is our usable battery
which is 12000WH
and our solar output
if we have three 100W solar panel
so 300 times 5 is 1500
so if we will
compute its cost
roughly is it 25k to 30k php (600US)
there you go a simple setup
always remember that solar panel
in series or parallel connection
but in my example I use a parallel connection because I use a PWM charge controller
there is a fuse
from solar panel going to charge controller
another fuse from charge controller going to battery
then battery going to inverter
we also put fuse
lastly the inverter where we
plug our AC devices
as of now, I don't have this kind of setup
but if I am going to setup
for my house
and switch to off grid setup
I will be needing this budget
this is the typical setup the I will use
for now, this is what I have
I have a solar backup
battery backup solar
I have a 100W Zocen
solar panel
and this is my 12V inverter
and I have a battery pack here
and a 1000W inverter
this one is just a battery backup
and my solar panel is not always connected here
because I am using my solar panel in my
grid tie setup at home
but when we do not have much load
I connect my battery backup to my solar panel
so that is its purpose
this is its specifications
solar output is 500WH
because I have a single 100W panel times 5 sun hours
battery is 36AH times 12V
432WH and our load
capacity is 250W
this is my backup and you can watch my full setup
in the "i" button
if you have questions
just comment down below
thank you for watching and don't forget to like
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