Monday 25 November 2013

OZ Newbie

Jacaranda bloom in spring

 
Before I decided to pursue my study in Australia, I practically just knew basic information about this world’s largest island (though some may say that Greenland should be the largest island). Not to mention my knowledge about Brisbane, I even pronounced it wrong. Nonetheless, Alhamdulillah I manage to come here and truth be told, I did not have any particular expectation. Maybe due to my age, I am more relaxed and prepared to accept what might come especially should anything unpleasant occur. 

I think the beginning of my surprise was during my first bus ride to school. I was really shocked when the bus driver greeted me, “Hello lady” the moment I hopped onto the bus. I was so used to being oblivious and minding my own business that the mere idea of someone took the effort to talk a stranger like me seemed insane. 

But another incident that took place in school was more interesting. Still in my first week, I just got back from a class and my mind was occupied with many errands to be done, thus I hardly took notice of anyone around. All of a sudden, I heard someone called a few times, “Hello, hello” from my back. I turned around and I saw a guy looked at me eagerly waiting for my response. Turned out I did not realize he greeted me, and yet he still anticipated my response. I thought the bus driver was out of his mind, but this guy was way crazier. At least that was what I thought at that time; however I finally enjoy this simple yet sweet gesture that lightens up my mood each day. 

Besides trying to adapt to this 'awkward' friendliness, I am also having a hard time understanding the Australian accent, especially when it is spoken in fast pace. If possible I would like to avoid even phone conversations; I'd rather resort to email. For all I know they sound like they speak another whole new language. I dread repeating “sorry” and “I beg your pardon” over and over again. Unfortunately there was one time that I had to settle an urgent matter with the Students Services Centre of my university (Queensland University of Technology). As the new semester had just started, there were so many students lining up to be served at centre's office. Waiting was not an attractive option for me since I got other things to do as well at that moment. I went back to my office and looked up the email address of the person in charge. In turn I found out that chat support service is provided! It was so convenient and I managed to settle the matter just through online conversation. As the Australians would say it, Ace! But still, I take note that I should get familiar with Australian accent as soon as possible. 

On a positive note, I lost weight since I came here thanks to at least two kilometres walk almost every day compared to my driving routine back home. Costly transport fee turns out to be a blessing in disguise. However, I still get abashed as I watch in admiration at the Australian elders who still take time to walk daily. Some of them even walk by pass me and I could just hold my embarrassment of being overtaken by an elder. 

Nevertheless, nothing could beat one memorable dramatic incident that happened about two months after I arrived here. During the stormy season in early February this year, out of panic I bought huge amount of groceries for emergency preparation and ended up unable to carry them all at once. I had to leave my backpack filled with groceries at the bus stop while carrying another load to a friend’s place nearby. It felt like a split second but when I returned my backpack was gone. I had taken my phone, purse and ID cards with me but I forgot to grab my home and office keys. I was on the verge of tears but still managed to recollect myself to ask people nearby in the midst of heavy windy rains. Sadly no one seemed to have any idea who took the backpack. Frustrated, I just wandered within the bus stop vicinity without knowing what else to do other than reporting to the cops. The chance of getting my stuffs backs seemed so slim. While muttering prayers and walking back and forth aimlessly, suddenly I heard honking sound from a car heading towards me. I thought I was in the way so I stepped aside. Instead, the driver opened the window, and right beside him on the passenger’s seat is my backpack, safe and sound!

He enquired whether the backpack belongs to me and I must say he looked like an angel from above, at least to my eyes. All I could remember I thanked him profusely while holding back tears and I did ask what his name is though I forget it already. He offered me a ride home yet I refused him politely since a friend’s place is just nearby. To this day I never met him again or maybe I could not recognize him anymore. The incident certainly shines in my memory and keeps me optimistic on encountering what may come throughout my journey here. Undoubtedly, I have a long way to go but I am definitely catching up mate!

By: Nur Idawati Md Enzai

Wednesday 20 November 2013

SIZING OF PV MODULE FOR SOLAR PROJECT


PV cell is the smallest semiconductor element that converts solar radiation into electrical energy. PV materials can be categorized as either crystalline or thin film. Crystalline Silicon which is commonly used in the wafer form in the PV modules. Crystalline cells are basically silica-based materials that has been melted and crystallized. Crystalline cells achieve higher efficiencies than thin film cells.
Due to these characteristics, monocrystalline PV module’s type have been widely used. So this articles will show the steps for sizing the PV module. Before we can start sizing the PV module, we must sizing the batteries for a system first. Below is the steps to sizing the PV module:
E module (Wh)  =  E load                                  (1)
            The first formula is the energy for the module. The energy for the module must be same with the energy for the load. The load energy’s formula is taken from the sizing the batteries.
P array (W) = E module ÷ Peak sun hour                    (2)
       For the second formula, the peak sun hour stands for the total time the sun will produce a maximum heat. Usually we set the peak sun hour for a day is 3 hours
P array stc (W) = P array ÷ Module derate factor                (3)
       The module derate factor is the percentage the PV module will generate the energy. Usually we assume every each of the PV module will generate only 0.75 (75%) only because of the dust that placed on the PV module.
       The last formula is the N module is the number of the modules that have to combine to operate the system. For an example, if the value of N module is 0.67, so the number of module that needed to operate the system is 1 unit.  
N module = P array stc ÷ P module stc                      (4)
       By the sizing the PV module, it can minimize the cost and also can full fill the requirement of the power that are needed to operate the system.

Written by:

AHMAD IZZAT BIN MOD ARIFIN

MOHD SAIFUL NAJIB BIN ISMAIL@MARZUKI

SIZING OF BATTERY FOR SOLAR PROJECT


Certain mathematical verifications were required to design a system in order to develop solar system. The first step was to calculate the power requirements of the load. This was done by listing each load and making an estimate for how much energy it would consume in a day. This can be done with measurement made use by multimeter to calculate both voltage and current in a range of time on the load with their conventional power supply. Base from the measurement, we can calculate power and watt-hour (Wh) on that time. The battery size calculated such as in equation (1), (2) and (3).

Eload (Wh)=∑ ( Vload x Iload x Time)                         (1)

Ebattery (V)= (Eload x Autonomy) ÷ (nbattery x DoD)              (2)

In the (2) formula, there are autonomy, nbattery, and DoD (Maximum Depth of Discharge). Autonomy is the number of days that the battery can support the system while the nbattery is the Battery Efficiency Factor. Usually the Battery Efficiency Factor is set to 0.9. Lastly, the Maximum Depth of Discharge is the percentage that percentage will use the storage of the battery. The standard value of Maximum Depth of Discharge for standalone PV system is 0.8.

AHbattery (AH)= Ebattery ÷ Vbattery                          (3)
           
In order to choose the battery size, the battery must have the AH value more than the calculated. The type of battery that have been widely use is Sealed Rechargeable Battery because of their characteristics. After that, the amount of the battery needed must be count as in equation (4) and (5) to know how many numbers of batteries that can be arrange in series and parallel base on earlier calculation.

Nparallel (unit) = AHbattery ÷ AH one battery                          (4)

Nseries (unit) = Vsystem ÷ Vone battery                        (5)


The sizing of the battery can help to minimize cost and also to count the ability of the system to get enough power from the battery. Then, the storage of the battery will support the system tally with the time that has been set.


Written by        : Mohd Saiful Najib Bin Ismail @ Marzuki
                           : Ahmad Izzat Bin Mod Arifin