Hybrid Solar Energy System (Brief)

Diesel ,Solar, Wind Hybrid System

The Concept of Hybrid Solar System is not specific all the time, it varies from system to system . But in most cases hybrid system contains a part which is off-grid or battery storage system and a part or combined parts of other energy sources or it could be grid-tied. 

Let me actually categorized for you .. In a Hybrid Solar System there are basically two parts i) Off-grid /On-grid Solar/Grid-tied  ii) Other Sources of Energy (Wind, hydro,Bio/Generators) 

These systems varies all the time but many hybrid systems are made of off-grid solar systems which are combined with other renewable or diesel generated energy sources.

Hybrid solar systems combines the best from grid-tied and off-grid solar systems. These systems can either be described as off-grid solar with utility backup power, or grid-tied solar with extra battery storage.

Grid_Tied Solar

Hybrid System also can be two renewable systems combination  where controllers controls battery charging from different  sources and later from inverters we get the AC output.

Wind,Solar Hybrid System

Hybrid Solar System Types : 

• Off -Grid Solar + On-Grid Solar (Grid-Tied)
• Off-grid Solar + Diesel Generator
• On-Grid Solar (Grid-Tied)+ Diesel Generator
• Off-grid Solar +Other Renewable (Wind, Hydro,Bio) 
• Off-grid Solar + Diesel Generator+ On-grid
• Off-grid Solar +Other Renewable (Wind, Hydro,Bio)  +Grid-Tied
• Off-grid Solar +Other Renewable (Wind, Hydro,Bio) +Diesel Generator +Grid-Tied
• Off-grid Solar +Other Renewable (Wind, Hydro,Bio) +Diesel Generator +Grid-Tied+Solar Thermal

 Advantages of Hybrid Systems :

• Save off-peak energy cost 
• Make Grid-free energy system 
• Create business opportunities with the government or local
• Save from load-shedding/black-our problems
• Highly advanced energy system 
• Help to improve individual home/business status
• Can eradicate financial issues by installing smart. 
• Better use of environmental resources  with conventional sources.

 Disadvantages of Hybrid Systems :

•  High initial Cost for set up a Hybrid System.
•  Very complex system for maintenance.
•  High observation is needed & monitoring is important.
•  Need more place to install. 

 Hope You Like this Post (jajakallahu khair)
 

Lead Acid Batteries @ Detailed...

In solar technology or building solar off-grid systems this lead acid batteries  are most known batteries because of its low price but effective performance.This is much practical way of storing sun energy.This is the same type of battery you used in car batteries.

This is ideal for home system where shed is available because heat drastically reduce the lifespan of these batteries.

Construction : Please Follow this link: Lead Acid Batteries

Electrochemistry : 

In the discharged state of a lead acid battery both the positive and the negative terminals become lead(II) sulfate (PbSO
4), and the electrolyte become more water by loosing the dissolved acids.The discharge process is driven by the conduction of the electrons from negative terminals to positive terminals.In the fully charged state, the negative plate consists of lead, and the positive plate lead dioxide, with the electrolyte of concentrated sulfuric acid.Overcharging with high charging voltages generates oxygen and hydrogen gas by electrolysis of water, which is lost to the cell. The design of some types of lead-acid battery allow the electrolyte level to be inspected and topped up with any water that has been lost.

Negative Plate Reaction : 

Pb(s) + HSO−
4(aq) → PbSO
4(s) + H+(aq) + 2e⁻

^{Positive Plate Reaction :}  

^{PbO
2(s) + HSO−
4(aq) + 3H+(aq) + 2e− → PbSO
4(s) + 2H
2O(l)}

^{Total  reaction :} 

^{Pb(s) + PbO
2(s) + 2H
2SO
4(aq) → 2PbSO
4(s) + 2H
2O(l)}

Types of Lead-acid Battery :

• Deep-Cycle Lead Acid Batteries.
• Flooded Lead Acid Batteries 
• VRLA Lead Acid Batteries 
• AGM Lead Acid Batteries 
• Gel Lead Acid Batteries 

Deep-Cycle Battery : Almost every battery used in Solar System are Deep-Cycle Batteries, this is one kind of lead-acid batteries designed to discharge high in capacity almost 45%~75%. In simple language deep-cycle battery is highly dis-chargeable batteries than other batteries i.e you can drain out much energy without harming their lifespan.The best lifespan vs cost method is to keep the average cycle at about 45% discharge. There is an indirect correlation between the depth of discharge (DOD) of the battery, and the number of charge and discharge cycles it can perform.

This deep-cycle batteries basically two types :  i)  Flooded Type ii) VRLA Type

Flooded Lead-acid batteries : The term "flooded" is used because this type of battery contains a quantity of electrolyte fluid so that the plates are completely submerged. The electrolyte level should be above the tops of plates which serves as a reservoir to make sure that water loss during charging does not lower the level below the plate tops and cause damage. Flooded batteries will decompose some water from the electrolyte during charging, so regular maintenance of flooded batteries requires inspection of electrolyte level and addition of water. Major modes of failure of deep-cycle batteries are loss of the active material due to shedding of the plates, and corrosion of the internal grid that supports active material. The capacity of a deep cycle battery is usually limited by electrolyte capacity and not by the plate mass, to improve life expectancy.


A valve-regulated lead-acid battery (VRLA battery) : This is also called sealed lead-acid (SLA). Due to their construction, the Gel and Absorbent Glass Mat (AGM) types of VRLA can be mounted in any orientation, and do not require constant maintenance. The term "maintenance free" is a misnomer as VRLA batteries still require cleaning and regular functional testing. They are widely used in large portable electrical devices, off-grid power systems and similar roles, where large amounts of storage are needed at a lower cost than other low-maintenance technologies like lithium-ion.

AGM (Absorbent glass mat) : This is one type of VRLA battery. AGM batteries differ from flooded lead acid batteries in that the electrolyte is held in the glass mats, as opposed to freely flooding the plates.The plates in an AGM battery may be any shape. Some are flat, others are bent or rolled. AGM batteries, AGM batteries presents better self discharging characteristics than conventional batteries in different range of temperatures.Very thin glass fibers are woven into a mat to increase surface area enough to hold sufficient electrolyte on the cells for their lifetime. The fibers that compose the fine glass mat do not absorb nor are they affected by the acidic electrolyte. These mats are wrung out 2–5% after being soaked in acids, prior to manufacture completion and sealing.As with lead-acid batteries to maximize the life of AGM battery is important to follow charging specifications and a voltage regulated charger is recommended. and also there is a correlation between the depth of discharge (DOD) and the Cycle life of the battery with differences between 500 and 1300 cycles depending on deep of discharge.

Gel battery : A modern gel battery (also known as a "gel cell") is a VRLA battery with a gelified electrolyte; the sulfuric acid is mixed with fumed silica, which makes the resulting mass gel-like and immobile. Unlike a flooded wet-cell lead-acid battery, these batteries do not need to be kept upright. Gel batteries reduce the electrolyte evaporation, spillage (and subsequent corrosion problems) common to the wet-cell battery, and boast greater resistance to shock and vibration. Chemically they are almost the same as wet (non-sealed) batteries except that the antimony in the lead plates is replaced by calcium, and gas recombination can take place.This sealed, non-spill feature made it possible to make very small VRLA batteries (1 –12 Amp hr. range) that fit into the growing portable electronics market. A large market for inexpensive smaller sealed lead acid batteries was generated quickly. Portable TV, light for news cameras, children's toy riding cars, emergency lighting, and UPS systems for computer back-up, to name a few, were powered with small sealed VRLA batteries.

Advantages of Lead Acid Batteries :

• Low cost compared to other batteries like Lithium-Ion.
• Robust,Reliable and Tolerant to abuse.
• Tolerant to overcharging.
• Low internal impedance.
• Can deliver very high currents.
• Can be left on trickle or float charge for prolonged periods.
• Wide range of sizes and capacities available.
• Many suppliers world wide.
• The world's most recycled product. 

Disadvantages of Lead Acid Batteries :

• They take up a lot of space, and many of them emit hydrogen gas. Hence the need for a battery-shed.
• They have a low cycle life (1000-3000 cycles), which means that, depending on how many time a day you charge and discharge them, they will only last  2-8 years tops.
• They generally have a depth of discharge of around 60%. This means that you can only use 60% of their capacity - otherwise you cripple their lifespan.
• Their performance figures are quoted at around 20 ºC ambient - meaning that if your battery shed gets hotter than this  their performance and lifespan will degrade.
• Sulphation may occur if a battery is stored for prolonged periods in a completely discharged state or very low state of charge, or if it is never fully charged.
• Contain hazardous materials  like lead, so not very environment friendly.
• Danger of overheating during charging, not suitable for fast charging.

Note : The Lead Acid batteries are worldly renown batteries, they are high is use due to their lower in cost & availability but still  better performance but this technology is getting outdated because of new coming like Lithium Ion or flow batteries or Ni-Cd Batteries which are higher in cost, so it depends on ones budget to determine how they will go. 

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Other Posts : 

• Flow Batteries 
• Lithium-ion Batteries

How To Read Solar Panel Specifications @

In Engineering this is one of the most important role which is reading the specification chart of any electrical apparatus. Today we are going to learn how to read a Solar Panel Data Sheet. Alhamdulillah.

Like every-other catalogues there are some keywords everyone should understand before they read any catalogue page for selecting any device.

To understand a Solar Panel Catalogue or Data Sheet one must know about Voc, Isc, Pax, Vmax, Imax at STC or Nominal case.

STC : This stands for Standard Temperature Condition. This is the condition for every solar panel get tested with. This is equal to 25℃ , 1.5 atmospheric density , 1000watt /square meter light intensity and sun’s angle directly perpendicular to the solar panel at 500 feet above the sea level.

NOCT : This stands for Normal Operating Cell Temperature. This is more practical data comparing with STC as STC is standards but it always close to the STC.

Voc : This stands for Open Circuit Voltage of the Solar Panels. This is  no load condition for solar panels when a multi-meter place  across the positive and the negative terminals of  a solar panel you get Voc.This is a very important number for creating series of solar panels  for charge controllers or inverter as it is the maximum voltage a solar panel can creates.


Isc : This stands for Short Circuit Currents of a  Solar Panel.This is the current rating when the output of a solar panel is short i.e positive and negative of a solar panel is connected directly without any load presents.This is the highest current a solar panel can provide.

Pmax : This means Maximum Power Point.This is the best power output you can expect from a solar panel. This is the power wattage which MPPT Charge Conroller tries to get and keep it. Pmax=Vmpp x Impp where Vmpp is the voltage at maximum power output and Impp is the current at maximum power output.

I-V Curves of Solar Panel : 

Edyeazul property

The picture  above is the I-V Curve of a solar panel where you can see multiple curves are placed on it but they are identical as curves but has different values.You can see in the above picture there is a  point where power starts to lowering down, this is call MPP (Maximum Power Point ), this is the maximum power a solar panel can provide. At this point you will find two more values one is Vmpp(Maximum power pint  Voltage) and Impp(Maximum power pint  Current.There are other two values you can find from this I-V curve i) Voc (Open Ciruit Voltage ) where solar panel current equals to zero ii)Isc (Short Circuit Current) where voltage equals to zero.

 Reading a Catalogue : 

Above the Picture you can see a catalogue of variety solar panels at first column you find model number of the panels, Next is Maximum Power ratings of solar panels (Pm) , as an example SD-HMB-18-20 shows 18W of maximum power (Mpp) which means this solar panel can give you maximum 18W, Open Ciruit Voltage 23.7V ( This is the no load voltage)  , Short Circuit Current is 0.98A(This is the short circuit current) ,Voltage at Mpp is 19.8V(This is the voltage when you get 18W) and Current at Mpp is 0.91A(This is the current when you get 18W), cell efficiency  20.30 % and others are just weight and dimensions. 

All of this readings are important when you classify any project,so keep in mind the terms because you will need it.

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A Brief Description On Home Solar System Costing

Benjamin is not for sale

Matter  of fact is that everyone wants to earn money but we forget that if we know how to save it before we lost it then your pocket is pretty much the best place you will want to touch.

To save money from Solar Technology, first of all you need to build a Solar System in your house. And to do that you need money at the beginning but you should be careful in few things. Let me list for you....

• There are few things that will be costly for you like Solar Panel, Battery, Inverter and some other things which are you can find in moderate prices like charge controller, cables , and installers. But this is only the equipment cost if you are installing from a company or dealer then there will be service cost too, so keep in mind about all the costs.
• The Solar Panel Cost actually depends on the load, the higher the load the higher the cost. You can use this tool to figure your Solar System Size SolarSizerCalculator.
• Solar Panel Cost are assigned with per watt which means if you need solar panel 100Watt and market price of that brand is 70BDT/Watt then you have to pay 7000BDT for 100Watt Solar Panel. Solar The simple rule is (BDT/Watt x Total Watt) which give you total panel cost. The price will vary about 10~20BDT/Watt depends on Brand or the Panel Type (Mono/Poly/Thin).
• Now let talk about the Battery Cost which is the most crucial and costly product of all but before that you need to know how to choose a Battery, please follow this link Battery Info (Please Read all posts). Please use this tool for your Battery Selection SolarSizerCalculator.
• Battery Cost also vary with the Brand to brand, you need to research your market for that. This cost vary from (8000BDT ~30000BDT) depending on Brand and its Ampere-Hour (AH) rating. In market you pay money for batteries based on its Ah (Ampere-Hour) rating, so calculate it before you go to dealers, please use this SolarSizerCalculator.
• Next is Inverter which is also costly but for house hold system it will come around at most 10000BDT~15000BDT but for certain case this could exceed to 30000BDT depending on its functionalities and power handling capacity. In market this product is sold on VA (volt-ampere) rating, higher the VA rating higher the price.
• Charge Controllers are the next thing you need to install with your Solar Home System. For normal Solar Home System this will be pretty cheap, you can get it at most 4000BDT for the best brand but it varies it prices between 1500~4000BDT depending on it Ampere rating and brands. In market Charge Controller are sold with its Ampere values like 5A, 10A or 20A. But all these information is for only Solar Home System which is below 20A Current ratings.
• Now what left is Cables, Connectors, Switches & Mounting Equipment cost? Cables cost are measured by its length,  so if your system is dealing with higher current like  20A or above then it will cost you more  but actually  cable cost entirely depends on the location and the system connection. If your system is zigzag or very complicated then cost can be higher, but you should counsel with engineer who monitoring these. Connectors are cheap as well as switches but again also if the system is big the price will be high, so can’t say for sure. These can only be done with experience and observation. And last is the solar mounting cost which is very much location and system dependent. These can be on the roof or on the ground but prices depend on how many solar panels are needed and what type installation is required. It could be pole based or railing based or you can make it your own using some support but depends on the system, so it needs observation. The entire cables, connectors, switches or mounting equipment’s can cost you like 8000~15000BDT together, so talk with the engineer.
• The last thing is the installation cost if you are not doing it your own or you are hiring an engineer or a builder for the installation then you has to pay them their service costs.

So keep in mind when you are trying to build your own solar system because this can be the best thing you can do for saving money for a long time which is an amazing decision.

Hope You Like This Post (JajaKallhuKhair)

Is Solar-Grid All we need ? @ a big question

A country development entirely depends on the on-growing development of technology specially energy sectors. Energy sectors are the foundation of the entire technology system, no energy no technology.

To develop a strong energy system in the country government usually takes a lot of initiatives to overcome scarcity in the energy sectors and in this frame the picture of solar technology shines with the bright smile.

developing countries like Bangladesh or other Asian or African countries are deprived of sufficient amount of energy sources. These countries can change their future only if they are smart enough to utilize natural sources with 100% efficiency. And what I mean by efficiency here, this means input of a country which includes labor and money and other resources.If an country can manage the input resources efficiently then  losses will be reduced and prosperity can be higher (InsaAllah)..

What is Solar -grid: This is  a power plant system of generating electricity  which includes solar technology (Solar Panels / Inverter/ Battery ). This is not a huge power giving grid , it is basically a mini or micro grid system where the output power is under 10MW. In Bangladesh it varies from 100KW~150KW most which is very small for locality. and it has long list of troubles which I mean authentic troubles.Let me list  it for you, 

• High in Investment and calculate in millions without government or foreign subsidy cannot be done .
• It takes a lot of space like a football field or something.
• High labor input and hard to manage human resource.
• High transportation cost for transferring heavy elements (Solar Panel/ Inverters).
• Need more work to set up whole system and needs long time.
• If anything happens in the solar-grid it is hard to find out and harder fixing it. 
• The line losses are high and for sure payment is high i.e electric bill.
• Very dangerous high voltage DC system.
• We can build more Small home Solar system if we use lost power in the solar -grid.
• The connections are complicated and friction loss is higher.
• There is extra cost for software installation and running it.
• Any kind of failure in grid can shut down entire load system.
• The electric charge is higher then the conventional.
• The connection cost from the grid to user takes additional charge and also takes metering charge.
• Normal people has less access to the technology. 
• It makes rich people rich and poor people poor.

 Solution : Solution to this all problems is build small but efficient solar systems which is different for different load system..

•  100W~2KW solar system for house hold , mosque, single shops.
•  2KW~20KW solar system for School, Colleges , Universities, Shopping Malls.
•  20KW~ above solar system for Small or medium Industries.

Note :   Small initiatives are the best for saving efficiency in the resources and make everyone part of the system , so no matter poor or rich can both can access and enjoy this growing technology..Ameen. :)


Hope This Post will be Helpful... (Jajakallahu khair)

How you know how much electric load in your house ??

What is Load : In electrical concept the power amount of  electric devices is called Load.  

Let me clarify for you.

If in your house you have a room in which you have a 70W of electric fan and  30W of CFL light and a Computer which consumes 120W, the total load of your room is summation of each power of each load.

That means Load of our room is  = (70+30+120 ) W = 220W total. (1st Room).

Now if you have another room which has a table lamp of 30W, a Table fan of 55W and a CRT Televison of 140W, then the Load of that second room is = (30+55+140) W = 225W total ( 2nd Room).

So if your house has only two rooms and nothing else then total Load of your house is = ( 1st+2nd) Room Load = (220+225)W = 445W of Total Load...But if your house has kitchen or Bathroom or other rooms then you have to calculate them manually then finally sum every loads of individual rooms.This is that simple.

note :  The necessity of knowing your house load information is very crucial and important.One should know his/her house load information for controlling the bills and the payment for electricity...

This is a very simple but very important knowledge that everyone should have...

Hope this post helps you(Jajakallahu Khair)