Power Inverter

Your inverter is simply the heart of your system as this is what converts the
dc voltage stored by your batteries into AC voltage that can now be used by
your home appliances.

Inverters are divided into 3

1.Square wave inverter

2.Modified sine wave inverter

3.Pure sine wave inverters

Square Wave Inverter

These are the least expensive and also the worst type of inverter to invest your money in. Don't consider buying it as the square wave it produces is inefficient and is usually very hard on many types of equipment you try to run on them

Modified Sinewave Inverter

These are the most commonly found inverters in the market today, although more expensive than the square wave inverters, they are still far more cheaper as compared to the pure sine wave inverter.
Almost all equipment's and gadgets will run relatively well on a modified sine-wave inverter exception of gadgets with motor speed controls or gadgets using timers. considering that more and more gadgets are beginning to have motor speed and timer controls, the modified sinewave inverter may not really be a good candidate Especially for people considering to run all home appliances from an alternative source other than the public utility grid.

Pure Sinewave Inverter

  The wave form generated by this type of inverters are almost pure sine wave in nature.
the pure sinewave inverter will run practically any appliance and in many cases produces
a cleaner power than the utility company itself. The Pure Sinewave inverter are the most
expensive inverters in the market and are almost twice the price of a modified sinewave
inverter. Regardless of the cost, they still remain the most efficient and most recommended
inverters worth investing your money in especially if you have plans of completely going of
the grid in the future.

Here is The wave form for Pure Sinewave, Modified Sinewave And square wave inverters

 Inverters have different  voltage systems ranging from 12, 24, 48 and even 96 volts, the higher the voltage, the lower the current and subsequently the more efficient your system would be because, there would be minimal energy losses, since the current would be considerable low as compared to the voltage.

Determining which voltage System to Use

The distance of your solar panels from batteries will determine the voltage system you are going to be using.
this means that the farther away your solar panels are from your batteries, the higher the voltage of your system has to be.

Inverter Stacking

Inverters can be stacked ether in series or in parallel, when stacked in series, the voltage across the board is increased, e.g you can stack two 120 volts inverters to give you a combined voltage of 240 volts.

But when in parallel  the current across the board is increased which also increases the current across the board and subsequently the overall power of your system.of your system. e.g if you stack two 1000Watts inverters together, you'll have a combined power of 2000Watts.

One advantage with stacking of inverters is the fact that its possible for your home to be running on one of them while the other one does the charging of you batteries.

You also get to have a backup such that if one of your inverters went bad, you wont be thrown in total darkness, while your faulty inverter is being fixed.

Please note that not all inverters are stackable, so u'll have to check with the manufacturer oem manuals for whatever brand you're installing so as to know what steps need to be taken for
proper and safe stacking,as well as the accessories that are needed to achieve this. This is so that you don't
endanger yourself and your property.

Inverter battery charging vs charge controller battery charging

New inverters this days are also capable of charging your batteries too, this can be especially useful assuming you are not fully dependent on the energy harvested from your panels or you you haven't yet purchased a solar panel and rely of the public power supply to charge you batteries.

But the problem with charging solely with your inverter is that some of them don't fully charge your batteries and usually just take your batteries to about 85 percent charge or there about, so the charge controller would usually be the one to take your batteries all the way up to 100%.

Secondly, when it comes to charging your batteries using your power inverter, you have to be careful and make sure the your inverter uses a 3 stage charging system to charge your batteries these are the Bulk, Absorption and the Float stages. But if your inverter just has the basic on and off charging system, be rest assured that you deep circle batteries will soon get damaged because they are not meant to be charged that way.

Some Brand Names of Inverters in the market today are: sukam. Luminous, cyber power, nexus e.t.c

Hybrid Solar Charging System

A hybrid system is simply one in which youu have more than one power source for charging your Batteries.
E.g, wind, solar and probably your public power supply (Utility Grid).

 What this does is to reduce your over dependence on your panels to solely charge your batteries
and also reduces the time ordinarily needed to fully charge your batteries to the brim.

Assuming your inverter which is connected to the public power supply is outputting, 30 amps and your charge controller recieving charge from your solar panels is  also outputting 30 amps, that will add up to 60 amps total, and what this will do is to slash down charging time to half.

 Please note that contrary to what people think, one charging source will not interfere with  the other, they only work together to bring the battery to full charge faster.

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Solar Panels

Solar Module (Panel) can be defined as  number of individual solar cells connected together in an environmentally
protected housing / casing  and produces  a standard output voltage and power.


 Hence Multiple modules/panels can be assembled into an array
 for increased power and/or voltage.
See Image below:

That means, a Solar Cell is The basic unit of a photo-voltaic solar panel.

A 12 volt solar panel typically has 36 individual cells, a 24 volt solar panel uses 72 cells.

  In summary, Solar panels are made up of solar cells that are connected together to form a module.

The cell   is primarily made up of silicon, and when placed under the sun they produce dc voltage. (D.C)


 Solar panels can last up to 20 years and even more. They can be Fixed, Adjustable or the
Tracking  Type.

Roof Mount

Ground Mount

Pole Mount

You can decide to go for a complete panel from manufacturers (already made) or build panels by yourself using solar cells.
 Solar panel is rated In watts e.g. you can have a panel rated 50 w, 100 watts, 200 watts etc.

Basically, There are three types of solar panels and they are:

a.Mono-crystalline Solar Panels

b.Poly-crystalline Solar panels

c.Amorphous Solar panels

a. Monocrystalline Panels: These are the most efficient and most expensive solar panels but i assure you that they are worth every penny you spend on them. these panels are made from monocrystalline cells, and are made from very pure silicon cells. this cells are sliced in from pure silicon rods into wafers that form the individual cells that make up the Solar panel (Module)

b. Poly Crystalline Solar Panels:
These panels are made from polychrystaline cells and are popularly called multicrystalline cells. they are much cheaper than the monocrystalline panels and this is because

The cells are grown in a block of many crystals and not in slices of wafer like the mono crystalline cells, and that is what give them the shattered glass appearance.

c.Amorphous Solar Panels: These are not really crystals, but a thin layer of silicon deposited on a base material such as metal or glass to create the solar panel.
They are are much cheaper, but their energy efficiency is also much less and because of this, more square footage is required to produce the same amount of power as the Monocrystalline or Polycrystalline type of solar panel.


When ever you want to purchase any solar panel, please pay close attention to the information written behind the panel. its very important.

Based On the screenshots above, there are some parameters you need to pay close attention to, they are:

 i   Maximum power rating  (Pmax)
 ii  Voltage at maximum power, (Vmp)
 iii Current at maximum power (Imp)
 iv Nominal operating temperature
 v  Cell technology.

This particular solar panel is meant for a 24 volts system, and because of that the actual voltage produced by the panels need to be high enough to prevent the backward flow of current from damaging you solar panels.

the product of the voltage produced  Vmp  and the current Imp produced at maximum power must be up to at least 85% of the panels rated power output

for instance the above panel has a power out put of 200watts. but if u multiply Vmp x Imp = 36.0 x 4.96

= 175 watts its not up to 200 Watts and the reason for this is stated in my previous post, in that post, i said that due to energy losses that occur, no system is capable of being 100 % efficient and so we assume an efficiency of 85% and then  factor it into whatever calculation we would be making.

 In this case the efficiency of our panel can be calculated as thus:

175Watts/200watts X  100= 87.5 Percent. this is very OK.

if you were using a poly-crystalline or amorphous panel, your efficiency would be considerably lower than the above.

Nominal operating temperature: This  refers to the maximum temperature the panels can withstand without having considerable effect on the power output.

Cell Technology is also very important too. as you can see, this particular panel is made of mono crystalline  and based on the comparison i made above i hope you now agree realize that mono-crystalline panels are the best most efficient solar panels your money can buy.

Points to Take Note of Regarding Solar Panels

1.Your solar panels should be far away from any shady area, if possible, cut any tree that may inter fare with  your panels from receiving direct sunlight, to prevent current from flowing backwards from your battery and destroying your solar panel.

2.Make sure your circuit breaker is switched of before you decide to carry out any routine maintenance or upgrade on your panels.

3.wipe your panels clean  at-least twice a year, to remove accumulated dust particles that may have settled on it.
Dust particles can reduced the efficiency of your solar panels, but if you live in an area that isn't that dusty, you could rely on rain Rain fall to wash your panels for you.

4.As previously stated in point 1, your solar panels should the installed far away from any nearby shade capable of casting it shadow on your panels, in other words your panels need to be installed where they can receive the maximum amount of sunlight  But, another problem you have to deal with is heat build-up because this can also become a problem. and the reason is Because the efficiency of solar panels decreases as temperature increases, putting that point into consideration, your solar panel  mounting system should have allowance between  the individual solar panels for air circulation. that way that way, your panels can easily be cooled despite being under the hot sun which would subsequently reduce the temperature of your panels.

this will also reduce wind resistance around your solar array since a path has now been created for the air to pass through.

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Some Basic Physics Formula's and Definations

Today, we are going to be talking about certain formulas an desalination  you need t know especially when it come to carring out sizing.

 Ohm's Law :Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference across the two points.The  formula that defines the relationship between resistance(R), voltage(V), and current(I) is V=IR,

Power: This is the rate at which energy is transferred, used, or transformed. Electrical power is rated in Watts and is equal to the product of Voltage (v) and current (I). As in P = V I.

Current This can be defined as the flow of electrons in an electrical circuit. it is measured in amperes (A)

Voltage: This is the difference in electrical potential that exists between two points in a circuit.
It is measured in volts.(v)

Watt-Hour: This is a unit of energy equivalent to one watt (1 W) of power expended for one hour (1 h) of time. - 1 watt produced or consumed for a period of 1 hour. it can be represented as (Wh)

Resistance: This can be defined as the opposition to the flow of current. it is measured in ohms

Since some of this definitions may seem a little abstract to some people, let me bring the above definitions home a little so you can have a better understanding of what am talking about.

Assuming we have water flowing from an overhead tank into the house for domestic use, then we would define the following as thus:

Voltage: This would be the equivalent of the water pressure in the pipe.

Current: This would be the equivalent of the rate of water flowing through the pipe

Power: This Could be defined as the Total amount of water flowing through the pipe based on the water pressure and the rate of flow.

The following formulas can be used to calculate the power flowing through a circuit

Power= V²/R =  I²/R  =  V x I

Where:

V = Voltage

R = Resistance

I = Current

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System Sizing

What is Sizing?

Sizing is simply the process of designin a solar electric system to
meet the required operating loads based on the total wattage of all appliances in the system.

For instance in you are using a tv set that consumes about 65 watts of
power, you  need to put into consideration how many hours a day you
intend to use the tv as it will help u calculate your total wattage in watt hour.

A lot of things needs to be put into consideration when  calculating the cost
 of setting up a solar generator.

First and foremost, you must consider the period of usable sunlight available
at your location

 For some of us who stay  close to the equator, we get about 7 to 8 hours
or more of sunlight during dry season, “this is just a just a rough estimate”

how to determine the size of solar panel needed for your project?

The power consumption of appliances is given in Watts hence To calculate
 the energy you will use over time, You  have to multiply the total power
consumption by the hours of usage.

Assuming I  have 100W tv set which I want to use for 8hrs,  20W dvd
player for the same period, and maybe  a 60W bulb for 5 hours.

To calculate the total power in watts hours, follow the following steps

The energy for each appliance is Watts x time (hours) = Wh

The energy used up by the tv in watt = 100 x 8 = 800Wh (watt hours)


The energy used dvd player = 25 x 8 = 200 Wh


the energy used bulb will be = 60 x 5 = 300Wh

 next we need to add up the total wattage consumed by the all the appliances
appliances

that would be  800+200+300=1,300 watt hour

This implies that the solar panel will need to supply 1,300 watt hours of energy
 to your batteries each day to cover the total power required by these appliances.

Since no system is 100 percent efficient as there are bound to be energy losses,
we have to take the losses into consideration by  multiplying  the result by 1.2
(this factor allows for natural system losses, and assumes an  85% efficiency).
Therefore, we will assume the panels will actually need to be able to supply a
 total of
1300 x 1.2 = 1560Wh

to be able to determine  the  solar panel capable of giving out 1560wh of energy we assume
to receive 7 hours of sunlight

The power rating of our needed solar panel will be = 1560Wh / 6 h = 260W

This means you will need a solar panel of not less than 260 watts.


Now assuming we have a Solar panel with a power rating of 200watts, we'll have
 to first apply  th 85% efficiency rule, and because of that it  means the panel will
only be able to deliver 200 x 0.85= 170 watts

Battery Sizing

Based of the calculations above,Your battery should be able to store
1560Wh of energy.
Since batteries capacities are rated in Ah (Ampere Hours) you need to multiply Ah by
the Volt rating to know the Watt Hour. Power(W) = Voltage (V) x Current (I) ;
Watt hour = V x I x Hour
We’ll make I the subject of the formula.

Therefore Ah (which is I x h) = Wh / V = 1560 / 12 (the number 12 represents
a 12v battery)= 130 Ah

This  means you will need not less than an 130Ah, 12V battery (deep-cycle batteries,
 not ordinary car batteries) to do the job.

This implies that the battery can supply a 260watt appliance for 1560/70 = 22 hours

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Overview / Introduction To The World Of Solar Energy

The unstable power supply / outrageous bill served by various power companies has made a lot of people resort to alternative sources of power, solar is one of those sources that the world is gradually becoming aware of because of Its friendliness to the environment.

For now it still remains one of the very many untapped resources especially in Africa.

This blog tries to explain c how solar energy can be put into good / profitable and productive use.

Let’s look at some advantages of solar Energy usage

 1. Lower or no electricity bills

 2.Compared to generator users, there is no fuel cost and stress of
    getting it and no fumes. Etc.

3.Little or no maintenance is usually carried out on your solar equipment, as long
    as you keep them in a well- ventilated area and away from moisture.

A solar powered generator  capable of converting the sun rays into usable electricity comprises of the following components:

1. Solar panel
2. Power Inverter
3. Deep Circle Battery
4. Charge controller
5. Suitable cables
6.Meter

Solar Panels

A solar panel is photo-voltaic device composed of groups of individual solar cells connected in series, in parallel, or in series-parallel combinations to produce a standard output.

You can decide to go for a complete panel from manufacturers (already made) or build panels by yourself using solar cells.
 Solar panel is rated In watts e.g. you can have a panel rated 50 w, 100 watts, 200 watts etc.

There are different brands of panels available in the market today, some of which are Sharp, Suntech, e.t.c

Power Inverter:

This is the heart of your system simply because it is  this device that converts your
stored battery charge from D.C to A.C.
In physics inversion is the conversion  of voltage from ac to dc.
So going by that definition an inverter is an electronic device that
converts 12, 24, 48, or higher volts DC power from batteries or solar
 panels to 120/240 volts AC to operate normal appliances.

Inverters are mainly divided into 2:

i,  Modified sine wave inverter
ii, Square wave inverter
iii, And pure sine wave inverter

 Out off all three, the pure sine wave inverters are the best because all appliances run smoothly on them as compared to the square wave and modified sine wave inverters where certain appliances  e.g  appliances that use motor speed controls or that use timers may not work quite right with a Modified Sine Wave inverter

There are so many inverters out there with different brand names some of which are sukam, cyberpower, nexus ,luminous  etc

  Storage Battery

Your batteries  are a very important part of your solar setup because this is where
your charges will be stored, which will consequently be converted from AC to DC
voltage by your inverter.

The only batteries that are  recommended for solar energy setups are deep cycle
batteries and this is because the are the only ones that have the ability to withstand
continuous charging and discharging and the the also allow you to take more charge
out of them than the regular car battery would.

Batteries can either be connected in series or in parallel.

 Parallel connections increase current output while voltage output remains
constant.while series connections increase voltage output while the current
 output remains constant. series and parrallel conections can also be combined
  to increase both the voltage and current output. See images below.

                                         Series Battery Connection 

                                         Parrallel Battery Connection

                                     

Charge controller

Just as the name suggests, a charge controller is a device that controls the
current entering the batteries and stops the it from  from overcharging,
 which could damage your batteries.

Once the battery is fully charged, the charge controller shuts off additional
current form reaching the battery.



Cables:Suitable cables with the right thickness must be used to avoid excess
energy loss when cables start heating up during usage.

Meter: The job of the meter is to simply tell you how much power
you are consuming on a daily basis.

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Solar Energy, A Better Alternative.

As the entire world seeks for alternative sources of energy due to the damage to the environment that is caused caused by the burning of fossils fuel, different alternatives are being considered.

When it comes to the area of power generation, solar energy stands out from amongst them all  because it i considered to be completely Eco friendly and does not in anyway have some sort of life threatening disadvantage or constitute some kind of bio hazard.

  Although setting up a solar generating  plant and going completely off the grid may b quite expensive, intact  i think that among other reasons the fear of how much it could cost  is what scares most people from enjoying the benefits solar energy has to offer.  But i can assure you that the benefits far outweigh the money u'll b spending... If you ask me, i think solar is the way to go.

Its advantages far out way whatever perceived disadvantages people may have about it.

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