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Know how to about Renewable Energy  :  

 

FAQ

Solar

Solar energy is energy from the sun. This energy drives climate and weather and supports virtually all life on Earth. Heat and light from the sun, along with solar-based resources such as wind and wave power, hydroelectricity and biomass, account for over 99.9 percent of the available flow of renewable energy.
Solar energy also describes technologies that utilize sunshine to produce other forms of energy. These technologies date from the time of the early Greeks, Native Americans and Chinese, who warmed their buildings simply by orienting them toward the sun. Modern solar technologies continue to harness the sun, but in more innovative ways, to provide heating, lighting, electricity and even flight.
The terms solar power and solar energy are often used synonymously but solar power usually refers to photovoltaic (PV) and concentrating solar thermal technologies that convert sunlight into electricity. In the case of solar PV, the process is direct, via silicon-based cells; in the case of solar concentrating thermal, the process involves heating a transfer fluid to produce steam to run a generator.
There are many technologies for harnessing solar energy within these broad classifications: active, passive, direct and indirect.

  • Active solar systems use electrical and mechanical components such as tracking mechanisms, pumps and fans to capture sunlight and process it into usable outputs such as heating, lighting or electricity.
  • Passive solar systems use non-mechanical techniques to control the capture of sunlight and distribute this energy into usable outputs such as heating, lighting, cooling or ventilation. These techniques include selecting materials with favorable thermal properties to absorb and retain energy, designing spaces that naturally circulate air to transfer energy and referencing the position of a building to the sun to enhance energy capture.
  • Direct solar generally refers to technologies or effects that involve a single-step conversion of sunlight that results in a usable form of energy.
  • Indirect solar generally refers to technologies or effects that involve multiple-step transformations of sunlight that result in a usable form of energy.

There is a good prospect of harnessing solar power in Bangladesh. In a recent study conducted by Renewable Energy Research Centre, it is found that average solar radiation varies between 4 to 6.5 kWhm-2day-1. Maximum amounts of radiation are available in the month of March-April and minimum in December-January. Following map has illustrated prospect of solar radiation in Bangladesh.

Solar irradiation maps of Bangladesh, Source: RERC 

 

What is Solar?

 

Solar energy is the cleanest and most inexhaustible of all known energy sources. Solar radiation is the heat, light and other radiation that is emitted form the sun. Solar radiation contains huge amounts of energy and is responsible for almost all the natural processes on earth. The suns energy, although plentiful, has been hard to directly harness until recently.
Solar Energy can be classified into two categories, Thermal and Light. Photo –voltaic cells (PV) use semiconductor-based technology to convert light energy directly into an electric current that can either be used immediately, or stored in a battery, for later use.

PV panels are now becoming widely used, as they are very versatile, and can be easily mounted on buildings and other structures. They can provide a clean, renewable energy source, which can supplement and thus minimize the use of mains electricity supply. In regions without main electricity supply such as remote communities, emergency phones etc, PV energy can provide a reliable supply of electricity. The disadvantage of PV panels is their high cost and relatively low energy conversion rate (only 13-15%). Thermal solar on the other hand has average efficiency levels 4-5 times that of PV, and is therefore much cheaper per unit of energy produced. 

Thermal energy can be used to passively heat buildings through the use of certain building materials and architectural design, or used directly to heat water for household use. In many regions, solar water heaters are now a viable supplement or alternative to electric or gas hot water production.

 

Thermal energy obtained form the sun can be used for a number of applications including producing hot water, space heating and even cooling via use of absorption chilling technology.

 

Using solar and other forms of renewable energy reduces reliance on fossil fuels for energy production, thus directly reducing CO2 emissions. CO2 emissions contribute to global warming, an environmental issue which is now of great concern. The average household can reduce CO2 emissions by as much as 20% by installing solar collector.

 

Flat plate thermal solar collectors have been in use for several decades, but only in relatively small numbers, particularly in Western countries. Evacuated tubes have also been in use for more than 20 years, but have been much more expensive than flat plate, and therefore only hosen for high temperature applications or by those with money.

 

In recent years the production volume of evacuated tubes has exploded, resulting in greatly lower manufacturing and material costs. The result is that evacuated tubes are now similar in price to flat plate, but with the insulating benefits of the evacuated tube, they are set to become the default choice for thermal solar applications worldwide.

 

What is Solar Energy?

 

The sun is a very powerful source of energy. Without the sun's heat and light, human life on earth would not be possible.

 All aspects of our daily life involve the use of energy: we use energy for transport, for production of food and water (pumping) and for heating or cooling our homes and offices. Fossil fuels such as oil, coal and natural gas are used most despite the fact that the amount of solar energy that reaches the earth in one day is more than sufficient to satisfy the world’s yearly energy demand.
Solar energy can be applied in many ways. Apart from simple forms of solar energy to dry clothes, heat water or buildings or dry agricultural produce (so called solar thermal energy; see Solar Heat), we can also use the power from the sun to produce electricity for households or offices (so called solar electricity or PV (from photovoltaic; see Solar Electricity)). Besides these direct forms of solar energy, also hydropower, wind and wave power originate from the energy of the sun and are in fact indirect forms of solar energy.

 

 

What is Solar Heat?

 

 

The energy of the sun can serve many purposes. One of them is to generate heat. This is what we call solar heat. Using solar collectors the sunlight is directly converted into heat.

The use of solar heat has many advantages. It is a clean, quiet and reliable energy source. Solar heating systems have been used since the 19th century. Nowadays the use of solar heat is widespread. World wide about seven million households presently use Solar Hot Water Systems.

In households connected to a public energy grid (electricity, gas) the use of a Solar Hot Water system can save 50% or more on the energy bill for domestic hot water preparation.

In remote areas without a connection to a public energy grid, solar energy is used for heating water for households and hospitals or for drying agricultural products.

 

 

The meaning of Solar Cell or PV

 

 

Solar Cell, PV and photovoltaic cell are different terms that are used to describe the same word, photovoltaic. The term photovoltaic comes from two words photo (light) and voltaic (voltage). The photovoltaic effect is the transformation of the sun's rays into electricity. The scientific investigation of the photovoltaic effect started in 1839, but the efficient solar cell could not be made. Until 1954, a silicon solar cell was developed and this kind of solar cell was used in specialized applications as satellites from 1959.

 

Conclusion
 

Solar cell is a device that is made up of semiconductor materials such as silicon, gallium arsenide, indium phosphide, cadmium telluride and copper indium diselenide, etc. that absorbs sunlight and converts them into electrical carrier, then separate to electrons and holes to produce energy at positive/negative junctions. If the positive and negative junctions of solar cell are connected to DC electrical equipment, it is workable.

 

Types of solar cell


There are three main cell types that classified by its manufacturing technology and the semiconductor.

 

Single Crystalline Silicon Solar Cell

Polycrystalline Silicon Solar Cell

Amorphous Silicon Solar Cell

   

 

  • Two types of crystalline silicon solar cell are single crystalline silicon solar cell, which is known as monocrystalline silicon solar cell, made by slicing wafers and polycrystalline silicon solar cell, made by sawing a block of silicon first into bars and then wafers. The crystalline silicon solar cell is very hard and thin.

  • Amorphous silicon solar cell is the best developed of the thin film technology, which its thickness is 0.5 micron (0.0005 millimeter) and lightweight with its efficiency of 5-10%.

  • Other semiconductors such as gallium arsenide, cadmium telluride and copper indium diselenide, etc. have both of single crystalline and of polycrystalline. The solar cell, which made by gallium arsenide is high efficiency about 20-25%.

The solar cell structure

 

The most type of semiconductor currently in use is silicon crystal, which is the inexpensive and most available semiconductor. Because silicon crystals are laminated into p-type and n-type region, it is used to make the solar cell. The silicon has been smelt and purified until it becomes crystals. Then doping atoms are to create a p-type and n-type region. P-type doping, the creation of excess holes, is achieved by incorporating and atoms with the boron and n-type doping, the creation of excess electrons, is achieved by incorporating an atom with the phosphorus. Once a p-n junction is created, electrical contacts are made to the front and the back of the cell by evaporation or screen-printing metal onto the wafer. The rear of the wafer can be completely covered by metal, the front has a grid pattern or thin lines of metal and the back has the metal, which block out the sun from the silicon.  
 

How solar cell works

 

 

 

 

 

When the sunlight strikes the solar cell surface, which consists of two types of materials, p-type and n-type semiconductor, and the cell creates charge carrier as electrons and holes. The internal field produced by junction separates some of the positive charges (holes) from the negative charges (electrons). The holes are swept into the positive or p-layer and the electrons are swept into the negative or n-layer. When a circuit is made, the free electrons have to pass through the load to recombine with the positive holes, current can be produced from the cells under illumination.  
 

For example, -a silicon solar cell, which its diameter is 4 inch typically, produces from 2 to 3 amperes and approximately 0.6 volts. Because the output current of each cell is very low, a number of cells are wired together to make a module to reach the required current. And these modules are wired into large arrays. The solar arrays wiring depend on current and voltage requirement.  

 

  • If the solar arrays are wired in parallel, the output current increases.

  • If the solar arrays are wired in series, the output voltage increases.  

Manufacture solar cells

The single crystal or monocrystalline solar cell has the process as below:  

The melt silicon has been grown at 1400 °C then drawn the crystal from the melted silicon by slowly decreasing the temperature until become a large single crystal ingot. The large single crystal ingots are sliced into the single crystal wafers.

The single crystal wafers were doping atoms to create a p-type and n-type region and thereby producing a p-n junction. This doping can be done by high temperature diffusion (900-1000 °C), where the wafers are placed in a furnace with the dopant to introduced as a vapour.

The polycrystalline solar cell has the process as below:  


The molten silicon is poured into a mould and allowed to set. Then it is sliced into   the wafers.  

The polycrystalline wafers were doping to create a p-type, n-type region and p-n junction same as the single  crystal solar cell process.  

 

The amorphous solar cell has the process as below:
 

The silane gas (SiH4) is reacted by Plasma Chemical Vapor Deposition device. The amorphous silicon is made by depositing silicon onto glass or another substrate material from a reactive gas. The layer thickness amounts to less than 1 micron (0.001 millimeter).  

When the silane gas reaction the dopants as phosphine and diborane are included to create a p-type,n-type region and p-n junction.

The p-n junction is made up of translucent junction as indium tin oxide.

 

The gallium arsenide solar cell has the process as below: 

The gallium arsenide crystal has been grown by a Liquid Phase Epitaxy furnace.

The p-type and n-type region are created by Molecular Beam Epitaxy device.  

Main features of solar cell

  • Use the natural power, sunlight, which is clean and non-polluting 

  • Efficiently use a renewable power source and no limiting

  • Able to be installed anywhere to produce and take direct current

  • Use no fuel other than sunlight

  • No burning and therefore no air and water pollution

  • Give off no waste and therefore harmless environment  

  • No moving parts so there is no mechanical noise being operation

  • Minimal maintenance requirement

  • Long lifespan and stable efficiency

  • Light weight, easy to install and transportable

  • With the modular characteristic, it can be constructed any sizes as required

  • Reduce collection of gases such as carbon monoxide, sulfur dioxide, hydrocarbon   and nitrogen, etc., which generated from fuel, coal and fossil fuel burning power plants. All decrease the impacts of energy on the environment like greenhouse effect, global warming, acid rain and air pollution, etc.  

The multifarious advantages of Solar Power

 

 

Nowadays, most of us use equipments, machines and tools to reduce our loads and make us more convenient. They are used in the office, industry or at home. The more varieties of electronic and electrical products, the more demand of electricity.

 

There are many power sources to generate electricity such as water turbine generator, wind turbines, steam turbines generator, coal, oil, fossil fuel, natural gas and nuclear power. As mentioned above, more and more electricity is demanded whilst the power sources will be a lack of power in the near future. During the process of electricity production, wastes, toxic gases (Carbon dioxide, Carbon monoxide, Sulfur dioxide) or smokes may be generated. These are one of factors that cause air pollution, acid rain and global warming. Besides, the nuclear power is not safe for uses. As long as the power demand remains consistent, the renewable energy source must be replaced. Especially, it is clean and environmental friendly. The solar power is one of the solution and being studied by several researchers and research groups.

 

The major component for producing the solar energy is solar cell or the other term is PV. PV is an abbreviation for Photovoltaic that means voltage generated from light or sunlight. Solar cell is made up of two crystalline silicon wafers. The rear of the wafer is doping with the phosphorous to create the electrical charges, electrons. When sunlight strikes the exposed surface, electrons move toward the inner wafer, which is doping with the boron to create the electrical charges and holes. There are different in potential between two layers. To produce sufficient electricity, a number of cells are wired together to becomes a module and these modules are wired into large arrays. The principle work of solar power is the sunlight is converted into the electricity and be charges the batteries for any applications or other purposes.

 

There are multifarious advantages of solar power; example include it is the natural power, free, unlimited, clean and non-polluting, no moving parts being operation, minimal maintenance need and easy to use. Moreover, it can be applied to everywhere that sunlight is visible, the hill, the island, the sea or even in outer space.

 

At this time, solar cell can be used in various applications including calculators, watches, microwave repeater stations, lighthouses, traffic lights, street lightings, motor boats, airplanes, water pumping for irrigations and satellites, etc. In several countries, the solar power stations are widely used to provide electrical power. In Thailand, the solar power stations are constructed for rural electrifications. Additionally, several groups involved with the solar power join the cooperation and extensively publicize about the solar power. Also, research and develop the solar cell.

 

see caption


    

 

 

Although, today we can produce electricity from the sun, unlimited power resource, the power research and development team still continuously progress to optimize the resources.  
 

Solar Home Systems

 

Bright Sunshine in your home

 

Solar home system is power sources for home appliances and suitable for household purposes. The stand-alone Solar Home lighting system is meant for illuminating homes using solar energy. The custom designed system has 9 watts CFL/FTL lamps and has been designed to operate for 4 hours daily with autonomy of 3 days.

This system has been engineered to light up places where grid power is not available. Solar home lighting system is autonomous and maintenance free. There is no operating cost in terms of electricity consumption and is environment friendly.

 

Features:

  • High reliability and durability  

  • Overcharge and deep discharge protection

  • Protected against short circuit  

  • Low maintenance lead acid tubular battery

 

Typical Applications:

  • Offices   

  • Schools/Collages

  • Residential Houses

  • Hospitals

  • Industries/Factories  

 

There are several sets as follows:

 

 

 

 

 

 

Description

Application

Solar home system; size 130 Wp

2 tubes of 10 W fluorescent lamps + radio or 21" TV
Approximate energy produced 400 Wh per day

Solar home system; size 400 Wp
* suitable for small size house

3 tubes of 18 W fluorescent lamps + radio + TV + fan + 20 liter refrigerator
Approximate energy produced 1 kWh per day

Solar home system; size 2000 Wp
* suitable for medium size house

fluorescent lamp + radio + TV + fan + large size refrigerator + water pump
Approximate energy produced 6 kWh per day

Solar home system; size 4000 Wp
* suitable for general house

Any appliances except air conditioner
Approximate energy produced 12 kWh per day

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Stand-alone Solar Systems

 

Stand-alone solar system is suitable for any areas where utility power line is not available. This system requires a charge controller to charge storage batteries for discharge to run electrical appliances.

 

 

 

 

 

Description

Production capacity

Small size stand-alone solar system

For small size school
15 kWh daily

Medium size stand-alone solar system

For community or medium size school
30 kWh daily

Large size stand-alone solar system

For medium size village
60 kWh daily

 

 

 

Street Lighting Systems

 

Lighting up the dark alleys

 

Solar lighting system is suitable for outdoor lighting such as street lighting. The stand alone
Solar Street Lighting System is used to illuminate dark streets using solar energy. The solar PV Module functions as a dusk sensor for automatically switching OFF at sunrise. The system has been designed to operate form dusk to dawn with autonomy of 5 days and ease of installation and maintenance.  


 

Features:  
 

High reliability and durability  

Overcharge and deep discharge protection

Protected against short circuit  

Automatic switch in and off  

Temperature compensated battery charging

 

Typical Applications:
 

 

Rural areas and villages  

Farms and Resorts  

Parks and Playgrounds

Gardens  

Forest Area  

 

 

 

 

 

 

Description

Application

Solar street light system; size 30 Wp Type 1

A 12 V 6 W LED lamp (yellow) 12 hours use

Solar street light system; size 30 Wp Type 2

A 24 V 7 W LED lamp (yellow) 12 hours use

Solar street light system; size 30 Wp Type 3

A 24 V 9 W LED lamp (yellow, white) 12 hours use

Solar street light system; size 30 Wp Type 4

A 24 V 11 W LED lamp (white) 12 hours use

Solar street light system; size 30 Wp Type 5

2 bulbs of 12 V 6 W LED lamp (yellow) 12 hours use

Solar street light system; size 30 Wp Type 6

2 bulbs of 24 V 7 W LED lamp (yellow) 12 hours use

Solar street light system; size 30 Wp Type 7

2 bulbs of 24 V 9 W LED lamp (yellow, white) 12 hours use

Solar street light system; size 30 Wp Type 8

2 bulbs of 24 V 11 W LED lamp (white) 12 hours use

 

 

 

Solar Water Pump System

 

The green way to grow green

 

Solar pump system is designed to substitute power from generator or utility power line. Its application is to pump water from reservoir and convey the water to point of use. Solar Pump system has been designed for pumping water where conventional grid supply is not available. Depending upon the depth of the water level and volume of water to be pumped, it can be designed and integrate both, submersible and non-submersible pumps of different capacities. Once installed, it does not require skilled personnel to maintain and operate the system. There is no running cost in terms of electricity consumption and is environment friendly. 

Features:

  • High reliability and durability  

  •  Maintenance free  

  • One time investment  

  • Stand-alone system  

  • No fuel needed  

  • No use of battery  

  • Unattached operation

Typical Applications:

  • Homes

  • Schools

  • Rural areas  

  • Small-scale micro-irrigation  

  • Gardens

Solar Water Pumping

 

 

 

 

 

Pumping  Description

If you need to supply water beyond the reach of the power lines, then solar power can solve the problem. Photovoltaic powered pumps provide a welcome alternative to fuel burning engines, windmills, and hand pumps. Thousand of solar powered pumps are working throughout the world. These produce best during sunny weather when the need for water is greatest.
 

How it works

 

Photovoltaic (PV) panels produce electricity from sunlight using silicon cells, with no moving parts. They have been mass-produced since 1979. They are reliable that most manufactures give up to a 25-year warranty they work well in cold or hot weather.

 

Solar water pumps are specially designed to utilize DC electric power from photovoltaic panels. They must work during low light conditions at reduced power without stalling or overheating. Low volume pumps use positive displacement (volumetric) mechanisms, which seal water in cavities and force it upward. Lift capacity is maintained even while pumping slowly. These mechanisms include diaphragm, vane, and piston pumps. These differ from a conventional centrifugal pump that needs to spin fast to work efficiently. Centrifugal pumps are used where higher volumes are required.

 

A surface pump is one that is mounted at ground level. A submersible pump is one that is lowered into the water. Most deep wells use submersible pumps.

 

A controlled or current booster is an electronic device used with most solar pumps. It acts like an automatic transmission, helping the pump to start and not to stall in weak sunlight.

 

A solar tracker may be used to tilt the PV array as the sun moves across the sky. This increases daily energy gain by as much as 55%. With more hours of peak sun, a smaller pump and power system may be used, thus reducing overall cost. Tracking works best in clear sunny weather. It is less effective in cloudy climates and on short winter days.

 

Storage is important, three to ten days storage may be required depending on climate and water usage. Most systems use water storage rather than batteries, for simplicity. A level sensor can turn the pump off when the water tank fills, to prevent overflow. A similar control can turn the pump off if the water source is drawn too low.

 

Compared with windmills, solar pumps arte less expensive, and much easier to install and maintain. They provide a more consistent supply of water. They can be installed in valleys and wooded areas where wind exposure is poor. A PV array may be placed some distance away from the pump itself, even several hundred feet (100 m) away.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Energy (solar) conservation products and system

 

 

 

 Model: Solar IPS (Hybrid System)

 

 

 

What is Hybrid? 

Hybrid type is one of the methods to maximize efficiency by combining more than two power generation types. Today combinations among alternative energy sources have been rapidly developed. 

This system is not only regarded as significant evolvement in the field of the combination among clean energy sources, but provides another advantage that the system becomes more stable as sufficient electric power is generated. More electricity can be generated and stored by taking advantage of both from conventional grid line power source and photovoltaic power source at the same time. 

Features: 

Solar gentle charging (Vdc) system for conventional AC- IPS. (Dual Charge) 



Design depends on required load calculation. 

 

A Standard Design Calculation (160 Wp) 


  
Specification: 
  
1. Solar PV Module 12 V. 160 W.  
2. Battery 12 V. 60 Ah.  
3. Inverter 1200 VA.  

Ichg = 2.35 × 4 = 9.4 Amp. 
6 Hrs Sun light can provide 56.4 Ah. energy 
With 10% Chg loss, 50.76 Ah. to battery 
Total power available = 12 V. × 50.76 Ah = 609 Wh 
    
With Inverter efficiency 85%, it can supply 520 Wh 
For supplying for 3 hours, the load should be 520/3 = 170 W (approx) 
  
Hence, 2 nos. × 60 Ah battery will serve for 3 hours at 170-Watt load having DoD 38% (approx).  

 

 

 

 1.  Solar PV Module   12 V. 160 W. 
  2.   Battery/2 nos.   12 V. 60 Amp 
  3.   Inverter (Dual charge system) with Rack   1200VA 
 4.  Panel mounting metal bracket   Slandered 
5  Charge Controller   12V.
 6.  Wire/Switch/ Nuts, fittings and installation charge   As per requirements 

 

 

Note: 


The inverter can handle up to 840 W. load and as such the panel and battery rating can be  increased to 4 times their present rating without changing the inverter. 

 

 

 

Note: The mentioned specifications and terms may change without prior notice.

 

 

   The Basics of Charge Controller

What is a solar charge controller? What does a charge controller do? 

A charge controller, or charge regulator regulates the voltage and current coming form the solar panels going to the battery. Most “12 volt” panels put out about 16 to 20 volts, so if there is no regulation the batteries will be damaged from overcharging. Most batteries need around 14 to 14.5 volts to get fully charged. 



 Do always need a charge controller? 
Generally, there is no need for a charge controller with the small maintenance, or trickle charge panels, such as the 1 to 5 watt panels. A rough rule is that if the panel out 1/60th or less per day of the rated battery capacity, you don't need one.



For example, a golf car battery is around 200 amp-hours. So to keep up a series pair of them (12 volts) just for maintenance or storage, you would want a panel that would give you around 1/2 of 1% of the battery capacity per day. Assume 5 hours sun per day. 200 amp-hours divided by 200 (.5%) gives you around 1 AH per day loss. A 5-watt solar panel will supply around .3 amps (1.5 AH per day), so a 5-watt panel will give you more than enough to keep the batteries up, but not so much as to damage them


Why 12 volt panels are 17 volts? 
   
The obvious question then comes up- “why aren’t panels just made to put out 12 volts”. The reason is that if you do that, the panels will provide power only when cool, under perfect conditions and, full sun. This is not something you can count on in most places. The panels need to provide some extra voltage so that when the sun is low in the sky, or have heavy haze, could cover, or high temperatures*, still get some output from the panel. A fully charged battery is around 12.7 volts, so the panel has to put out at least that much under worst-case conditions.

Detailed information on MPPT (Maximum power point Traking) charge controllers? 

The charge controller regulates this 16 to 20 volts output of the panel down to what the battery needs at the time. This voltage will vary from about 10.5 to 14.6 depending on the state of charge of the battery, the type of battery, and temperature. 

Contrary to intuition, solar panels work best at cooler temperatures-in fact, some of the so-called “self regulating” panels (low voltage) will not charge a battery in temperatures commonly found in hot climates. 

Charger Controller Types 
Charge controls come in all shapes, sizes, features, and price ranges. They range from the small 4.5 amp control, up to the 60amp Outback Power MPPT programmable with computer interface. Often, if currents over 40 amps are required, two or more 20 to 40 amp units are wired in parallel. The most common controls used for all battery-based systems are in the 6 to 40 amp range. 

Charge controls come in 3 general types (with some overlap): 
 
Simple 1 to 2 stage controls, which rely on relays or shunt transistors to control the voltage in one or two steps. These essentially just short or disconnect the solar panel when a certain voltage is reached. For all practical purposes these are dinosaurs, but you still see a few on old systems. Their only real claim to fame is their reliability-they have so few components, there is not much to break. 

3-stage and/or PWM, these are pretty much the industry standard now, but you will occasionally still see some of the older shunt/relay types around, such as in the very cheap systems offered by discounters and mass marketers. 

The maximum power point tracking ones (MPPT), such as those made Outback Power. These are the ultimate in controllers, with prices to match-but with efficiencies in the 96 to 98% range; they can save considerable money on larger systems since they provide 15 to 30% more power to the battery. 

Most controllers come with some kind of indicator, either a simple LED, a series of LED’s, or digital meter. Some newer ones have built in computer interfaces for monitoring and control. The simplest usually have only a couple of small LED lamps, which show that you have power and that you are getting some kind of charge. Most of those with meters will show both voltage and the current coming from the panels and the battery voltage. Some also show how much current is being pulled from the LOAD terminals. 

All of the charge controllers that we stock are 3 or 4 stage PWM types, including the MPPT units. (in reality, “4-stage” is somewhat advertising hype- it used to be called equalize, but someone decided that 4 stage was better than 3). And now we even see one that advertised as “5 stage”….. 

What is Equalization?
 
Equalization does somewhat what the name implies- it attempts to equalize –or make all cells in the battery or battery bank of exactly equal charge. Essentially it is a period of overcharge, usually in the 15 to 15.5 volt range. If you have some cells in the string lower than others, it will bring them all up to full capacity. In flooded batteries, it also serves the important function of stirring up the liquid in the batteries by causing gas bubbles. Of course, in an RV or boat, this does not usually do much for you unless you have been parked for months, as normal movement will accomplish the some thing. Also, in systems with small panels you may not get enough current to really do much bubbling.

What is PWM? 

Quite a few charge controls have a “PWM” mode. PWM stands for Pulse Width Modulation. PWM is often used as one method of float charging. Instead of steady output from the controller, it sends out a series of short charging pluses to the battery- a very rapid “on–off” switch. The controller constantly checks the state of the battery to determine how fast to send pulses, and how long (wide) the pulses will be. In a fully charged battery with no load, it may just “tick” every few seconds and send a short pulse to the battery. In a discharge battery, the pulses would be very long and almost continuous, or the controller may go into “full on” mode. The controller checks the state of charge on the battery between pulses and adjusts itself each time.

What is load, or “Low Voltage Disconnect” output? 

Some controllers also have a “LOAD”, or LVD output, which can be used for smaller loads, such as small appliances and lights. The advantage is that the load terminals have a low voltage disconnect, so it will turn off whatever is connected to the load terminals and keep form running the battery down too far. The LOAD output is often used for small non-critical loads, such as lights. A few can also be used as a lighting controller, to turn lighting on at dark. Most systems do NOT need the LVD function- it can drive only smaller loads. Depending on the rating of the controller, this may be from 6 to 30 amps. You cannot run any but the smallest inverter from the LOAD output. On some controllers, series, the load output can be used to drive a heavy duty relay for load control, gen start etc. 

What is a “ Battery system Monitor”?

Battery system monitors are not controllers. Instead, they monitor your battery system components and give you a pretty good idea of what you are using and generating. They generally keep track of the total amp-hours into and out of the batteries, and the battery state of charge, and other information. They can be very useful for medium to large systems for tracking exactly what your system is doing with various charging sources. They are somewhat overkill for small systems, but are kind of a fun toy it you want to see what every amp is doing :-). Some models also has computer interface and many other features. 

 

 

 

          

What is it used for?

 

Livestock watering: Cattle ranchers in North America, Mexico and Australia are enthusiastic solar pump users. Their water sources are sources are scattered over vast rangeland where power lines are few and costs of transport and maintenance are high. Some ranchers use solar pumps to distribute water through several miles (over 5 km) of pipelines. Others use portable systems, moving them from one water source to another.

 

Irrigation: Solar pumps are used on small farms, orchards and gardens. It is most economical to pump PV array direct (without a battery), store water in a tank, and distribute it by gravity flow. Where pressurizing is required, storage batteries stabilize the voltage for consistent flow and distribution, and may eliminate the need for a storage tank.

 

Domestic Water: Solar pumps are used for private homes, villages medical, clinics, Schools etc. A water pump can be powered by its own PV array or by a minimal system that power lights and appliances. In a combined system, more configurations are possible. An elevated storage tank may be used or a second pump called a booster pump can provide water pressure. Or, the main battery system can provide storage instead of a tank. Rain catchments can supplement solar pumping when sunshine is scarce. To design a system, it helps to view the whole picture and consider all the resources.

 

Thinking small

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

There are no limits to how large a solar pump can be built. But, they tend to be most competitive in small installations where combustion engines are least economical. The smallest solar pumps require less then 150 watts, and can lift water from depths exceeding 200 feet (65m) at 1.5 gallons (5.7 liters) per minute. You may be surprised by the performance of such a small system. In a 10 –hour sunny day it can lift 900 gallons (3400 liters). That’s enough to supply several families, 30 head of cattle or 40 fruit trees!  


Slow solar pumping lets us utilize low-yield water sources. It also reduces the cost of long pipelines, since small-sized pipe may be used. The length of piping has little bearing on the energy required to pump, so water can be pushed over great distance at low cost. Small solar pumps may be installed without heavy equipment or special skills.     


The most effective way to minimize the cost of solar pumping is minimize water demand through conservation. Drip irrigation, for example, may reduce consumption to less than half that of traditional methods. In homes, low water toilets can reduce total domestic use by half Water efficiency is a primary consideration in solar pumping economics.

 

 

 

 

 

 

 

 

 

 

 

 

A Careful Design Approach:


When a generator or utility mains are present, we use a relatively large pump and turn it on only as needed. With solar pumping, we don’t have this luxury. Photovoltaic panels are expensive, so we must size our systems carefully. It is like fitting a suit of clothes: you need all the measurements. Here is a guide to the  data that you will need to determine feasibility, to design a system, or to request a quote from us SUN’NRG.

 

Solar pump Design Questionnaire

 1. Well depth or description of water source
 2. Depth to water surface: Does it vary?
 3. Yield of well in gallons per minute
 4. Total vertical lift from water surface to outlet
 5. Inside diameter of well casing
 6. Water requirements in gallons per day according to season
 7. Will other sources of water be available
 8. Use of water. Home Livestock Irrigation
 9. Describe any existing system at the site.
10. Quality of water: Clear Sandy Mineralized Other
11. Is pressure required for delivery?
12. Can a storage tank be located higher than the point of use?
13. Will the pump be located near a home/battery system? Distance?
14. Geographical location of system, plus any solar data available.
15. Solar access: Describe any obstructions at the system site.
16. Complex terrain? Include a map or diagram
17. Gravity feed System

Our first choice for a domestic water system is gravity feed. With gravity feed, water is stored in a large holding tank above the house and ideally is filled from a water source above the point of storage. (For every foot of elevation get 45# pressure.) If a site does not allow for direct filling of the tank then an AC or DC pump will have to be used.  

 

 

 

 

 

 

Concept Note

 

 

 

Research Title

Wind and Solar Energy Based Irrigation Project

Research Theme 

Solar and wind energy utilization for irrigation pump to minimize the environmental degradation due to fossil fuel emission in agricultural environment.

Location of project

Dhaka Mymensingh, Rajshahi, Bogra, Dinajpur Kustia, Cumilla and Chittagong.

 

 

 

Background:
  
Now a days, agricultural mechanization i.e water and farm machinery is considered a very important component for agricultural development. Farm power has become a critically important input in agricultural production and irrigation is the second only to land as the major means of production in Bangladesh. It has a total of 14.3 million ha of land of which net cultivable area is to be about 9.03 million ha (mha). and 7.56 mha is potential irrigable area. About 67 per cent of the total irrigable and has come under irrigation by the end of 2002, out of which minor irrigation covered about 90 per cent and ground water covered 70 per cent of irrigated area. Rice and wheat cover 90 per cent of the irrigated areas. Only 2 per cent irrigated area is under other crops. 1.26 Million mechanized irrigation equipments are operated for irrigation in every year.

 

Only 0.14 million equipments are operated by electricity and 89 per cent prime movers are operated by diesel. 1.12 million irrigation equipments are Deep Tube well (DTW), Shallow Tube well (STW) and Low Lift Pump (LLP) out of which sallow tube well is the most popular irrigation equipment in Bangladesh.

 

More than 20 models of diesel engines are imported from England Germany, Japan, Italy, Korea, China and India. Chinese diesel engines are more popular in Bangladesh. These engines are producing energy  (Horse power-hp) ranges from 3.6 to 32 hp and specific fuel consumption ranges from 0.21 to 0.29 li/hr or 220 to 300 gm/kwh. 12350 billion litre of diesel is required to operate this irrigation equipment in a year to irrigate 5.06 million ha of land. About 35 per cent environment is polluted due to burning of this huge volume of diesel. It is absolutely a great stress on fossil fuel.

 

Solar and wind energy in the most important renewable energy in the world. The sun showers 1.36 kw power in every cubic meter area of earth. This abandon source of energy is the resources for Bangladesh for generating clean energy i-e solar energy. The energy obtained from the sun without any combustion is safer and cleaner than coal, oil and unclear energy sources. So that solar and wind energy could be used as the alternative source of fossil fuel.

 

Solar and wind energy will be converted to the electrical energy by means of mechanical converter, these electrical energy will operate the prime mover of irrigation pump.

 

Initial investment is very high for the setting of solar panel but it dose not requires any operating money after first year up to next 20 years. Operational expenditure is very minimum and dose not requires any raw materials (except the sun racy which is free) for energy productions compare to diesel engine. Solar energy user farmer can get energy without any fuel consumption for at least 20 years. This long-term economic benefit will grow attraction of neighboring farmers to have the technology, which is the most important indicator of technology sustainability. It is a complete independent electric system having no load shading which is more safe and transferable to the users. Solar electric system is absolutely an environment friendly energy producing technology because it has no emission to the environment. Utilization of solar energy producing technology must curtail the dependency of fossil fuel and any crisis of fossil fuel dose not hamper the farmers activities.

 

Now it is the write time to release the stress on fossil fuel through wind and solar energy adaptation and refresh the environment as possible as we could.

 

Specific objectives:  

 

Specific objectives of this pilot study project are as follows;

  • To assess the technical feasibility of solar and wind pump in relation to water availability, soil type and rice/ non-rice water needs in selected areas

  • To assess the operational suitability of solar and wind pump in relation to the management capabilities of farmers.

  • To evaluate the economic viability of solar and wind pump for rain fed rice, vegetable and pulse crop production.

  • To evaluate the farmers affordability of solar and wind pump for irrigation.

 

Site selection:  


Ten locations were selected for this pilot study. The ten location are as follows; 
Dhamrai, Delduare, Mymensingh, B-Baria, Mohadevpur, Shibhonj, Domar, Magura, Hakimpure and Rangamati are under 10 agro-ecological zones. These locations are considered where farmer uses intensive diesel operated prime mover for irrigation pump.

Output:  
The study is expected that combine solar and wind energy utilization called Hybrid for irrigation will be available to the small scaled irrigation pump owners. After completion of this study a suitable technique will be developed which creates and environment to easy afford of solar and wind energy. 

 

 

 

 

 

 

Description

Capacity

Solar pump system; size 50 Wp/ Surface DC Pumps

Pump 1600 liter/day and lift up 6 meter high

Solar pump system; size 350 Wp/ Submersible DC Pumps

Pump 3500 liter/day and lift up 30 meter high

Solar pump system; size 600 Wp/ Submersible DC Pumps

Pump 7500 liter/day and lift up 38 meter high

Solar pump system; size 900 Wp/ Submersible DC Pumps

Pump 15000 liter/day and lift up 38 meter high

Solar pump system for agriculture and irrigation Type 1/ Surface DC Pumps

Pump 12150 liter/day and lift up 6 meter high

Solar pump system for agriculture and irrigation Type 2/ Surface DC Pumps

Pump 12150 liter/day and lift up 8.5 meter high

Solar pump system for agriculture and irrigation Type 3/ Surface DC Pumps

Pump 12150 liter/day and lift up 13 meter high

Solar pump system for agriculture and irrigation Type 4/ Surface DC Pumps

Pump 45000 liter/day and lift up 20 meter high    

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Grid connected Solar Systems

 

Grid connected solar system is hooked to utility power line. DC power from solar panel is delivered to grid-connected inverter and converted to AC power, then consumed by appliance. If the power is not enough, utility power will be drawn (buy). If there is excess power, it will push that power back to utility power line (sell).

 
 

 

Description

Production capacity

Grid connected solar system; size 2500 Wp

2770 kWh per year

Grid connected solar system; size 2800 Wp

2990 kWh per year

Grid connected solar system; size 3800 Wp

4860 kWh per year

Grid connected solar system; size 4600 Wp

4880 kWh per year

Grid connected solar system; size 4800 Wp

4990 kWh per year

 

 

40 kWp Grid connected Power System with Monitoring and Management Software


The system is designed to generate the DC power from solar panels that is delivered to grid connected inverter and converted to AC power, then consumed by appliances. The monitoring and management software is included in this system for displaying the total of system power generating on Plasma TV.

 

For Information only.

 

 

 

 

The system has been installed and applied at Saint-Gobain Sekurit (Thailand)

 


     

 

Solar Collector (Thermal)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

How It Works

 

 

Key Features

  • Using your existing pump, water is directed through a series of valves to the System

  • Water enters the solar collectors from the bottom and rises to the top through the individual tubes of the collector.

  • As water passed through the collector, it is heated by the sun's radiant energy.

  • The heated water is then returned to recirculate into the system for further use according to application.

 

 

  • Inexpensive and easy to install. No additional expense after installation

  • Uneasy crack or broken. No problems with clogs or leaks

  • Lightweight and durable. No metal components

  • Increasing water temperature before entering the boiler which effectively reduces the cost and energy consumption for heating water

  • Breakeven period approximately 2-3 years

  • More than 10 years life expectancy

  • Suitable for production processes requiring high volume of hot water such as industries, hotels or spas etc.

 

 

 

 

 

 

 

Time to change

 

 

from…

 

 

 

( Kerosene lamp)

 

 

 

To .....

 

 

 

Solar Energy LED based Home Lighting System

 

Photo of: Woman sewing

 

Dignity through Electricity Program

 

 

Bring Light to Family in darkness and create a cleaner Environment.

 

 

The Environmental Problem: Green Gases and Global Warming

 

Bangladesh has Millions Rural Homes. Out of this about 80% still burn kerosene for lighting. Each family consumes between 30 – 50 liters of kerosene per annum. Each liter of kerosene burnt generates 2.6 –3.0 kgs of Carbon Dioxide …These Millions of Families add over Million Tons of Carbon Dioxide annually. This Carbon Dioxide is a major Greenhouse gas and contributes Global Warming.

The Human Problem……… Life after Sunset

For millions of Village Homes life comes to a grinding halt with sunset. Having spent the major part of the day in the fields, the villager can do very little useful work in the darkness. Children cannot study and the villager and his wife cannot learn any new skills nor can they do any village craft. There is no entertainer or education through television.

 

Useful hours extended after sunset add Dignity to Living…  

 

Solar Energy and Technology: The Solution

 

Combining the Sun’s Energy with modern Technology has now provided mankind with solutions to the above problem. We extended the villager’s useful hours after sunset by providing him Lights power by solar Energy. This LED based lighting System is Non-polluting and eliminates the carbon dioxide being emitted from rural homes.

Solar is convenient

 

Of all the Renewable Energy sources available solar has been chosen as the primary source of energy charging, due to ease of operation, universal availability and drop in costs of systems over the years. When the energy systems are decentralized to the home level, solar becomes the only viable option.

 

Apart from being convenient and cost effective, …. Solar Energy is Free, Renewable and in abundance in Bangladesh. … Bangladesh receives  average 300 clear sunny days in the year.

 

Genesis

 

SNB has taken upon eh challenge posed by Village Lighting problems. It has promoted the Dignity through Electricity program.

 

SNB has an integrated program, which includes R & D, Sourcing, Designing and installing complete Solar and uninterrupted lighting systems in villages. SNB has a core Team consisting of Technocrats and Entrepreneurs driven by a single-minded passion to find cost effective solution to the problems and to achieve sizable coverage of the population needing assistance.  

Program Objectives are:

 

 

 

     To make available of Solar Powered LED Lighting Systems to the village who live in total darkness.
     Extremely high quality Light shall be available for a minimum of 4-5 hours every evening.
     To create a large population of donors both individuals and institutions who are keen to fulfill their Social  
       Responsibilities to the Society.
     To achieve lowest price points as compared to other options available
     To achieve a minimum direct coverage of 2500 homes every year.

 

Wherever, whenever, independence. Thanks to electricity from the sun

 

Stand-alone systems often represent the best alternative in locations where a regular power supply via the mains grid would be too expensive, technically difficult or even impossible. They are clean, they are economic, and they can be used with a great deal of flexibility. For many people these systems mean that they do not have to sacrifice convenience, while for others it means that they can enjoy electric light for the first time ever. Residential electricity, street lighting, water pumps, communications facilities, electric corrosion protection or hybrid system that are supported by bio-energy, wind power or other forms of generation- there are many possible applications. SUN’NRG develops the optimum standalone solution, be it for the private consumer, for commercial use, or for the electrification of entire regions.

 

 

 

 

 

 

 

 

 

 

 

The sun is here

 

 

 

 

A solar hot water system has many uses around your home

 

 

 

“VILLAGE POWER SUPPLY” BY SUN’NRG

 

Many Bangladesh villages do not have an electricity supply due to inadequate infrastructure.

This power supply systems are able to provide a continuous supply of solar electricity to a whole village. This enables regional development potential and increases the general standard of living.

Advantages:

            Profitable source of renewable energy  
            Environmentally-friendly with no emissions, noise and oil pollution  
            Guarantees a long-term electricity supply  
            Enables new development potential  
            Raises the general standard of living   

 

 

Decentralized self administration

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1. Solar Panel
2. Charge Controller
3. Storage Battery
4. Grid Line Electricity
5. Home Utility/Appliance

 

 

Nationwide or functional electricity supply networks are not available in Bangladesh. High-energy prices and insufficient supply guarantees are often the consequence, whereby electricity demand cannot always be met. Solar Home Systems provide a decentralized and self-administered energy supply infrastructure. This enables a high level of autonomy. 

 

Advantages: 

 

Ø      Independence form the local electricity supply network

Ø      No environmental pollution resulting from diesel gases and generator oil

Ø      Maintenance-friendly

Ø      Low running costs

Ø      Profitable source of renewable energy

Ø      Local development potential 

Ø      Raising the standard of living

 

 

Shedding light on the dark

 

 

 

Solar powered street lighting can help revitalize streets. Light produced in the way helps improve people’s quality of life and provides a higher standard of living. During the day the batteries are charged until there is sufficient electricity to supply the streetlights for the entire night.

 

 

Advantages:

 

 

Independence from the local electricity market  

Environmentally friendly and renewable energy source

Improves the quality of life

Expansion of public life

 

 

 

Enjoying the heat of the sun, every day

 

 

One possibility of using the endless and free energy of the sun is the conversion of light into electric current. Capturing its heat by means of solar thermal collectors and using it for own domestic purposes is another. In these times of rapidly increasing prices for conventional energy sources such as oil and gas there is a considerable savings potential through the use of solar thermal systems. One can enjoy the natural heat when showering, washing dishes or clothes, or back up space heating on a sustained basis by means of perfectly matched complete systems form SUN’NRG. Public institutions, sports facilities and hotels can offer their customers the convenience of hot water form a renewable energy source on a large scale in the form of solar thermal heating. In many countries this will allow to meet the construction requirements for improving the energy balance, and in a very cost-effective way that is also good for public relations. Further more, solar thermal technology helps reduce CO2 emissions and actively contributes to protecting the environment. 

 

Advantages:  

Reduced heating and hot water costs

Independence form heating oil price fluctuations and increases

No environmental pollution, emissions and oil leakages

Technically reliable and long life components

Profitability

 

The profitability of solar thermal plants is heavily dependent on the trends of heating oil prices. These are currently at a historic high of 60 Dollars per barrel (last updated 7/2005).

 

Recent forecasts by a US investment bank predict and explosion in the price of heating oil over the next few years, even at an annual rise of 10 percent (comparable with the period 1999 to 2005) the use of solar thermal technology will become increasingly viable. In view of the shrinking oil and gas reserves, the decentralized production of solar heat represents a wise investment for the future.

 

Solar thermal systems have a minimum life of 20 years. Little maintenance is required.

 

A collector surface area of 10 qm and a storage volume of 500 liters is sufficient to supply a household of 4 persons with hot water and supplementary heating.

 

Sun outside cool inside

 

A new technology is winning recognition: solar cooling. What sounds like a contradiction in terms is based on an ingenious principle? The cause of the heating supplies the energy for cooling. The stronger the hot solar irradiation and the greater the need for air conditioning, the greater the benefits in terms of cost-effective and environmentally friendly energy. In many countries around the world in which the demand for electricity peaks due to the wide-spread use of air conditioning systems during the summer months, solar cooling can prevent full load or even overloading of the power grids. For building owners, especially in the commercial sector, it stands for the comfort of pleasant temperatures combined with low costs and maximum reliability.

 

 

Remote solar panels, India

Remote solar home, India

 

 

Products

 

SNB is focused initially on two-path breaking Technologies: Light Emitting Diodes (LED) and Thin Film Solar (Amorphous Silicon) Panels to create a Low Energy. Low Cost and reliable solution to the Rural Lighting problem. 

 

LED Lantern

Lighting up lives with rays of sunshine

 

 

Solar LED lantern has been designed to provide portable and low cost, improved lighting for rural areas where grid supply is not available. It can also be used in urban area as standby to grid supply or for emergency lighting purpose. Its design is robust and attractive and gives 3600 spread of Light.

 

The Lantern is supplied with rechargeable sealed lead-acid battery, with deep discharge and high cycle performance characteristics. The battery can be fully charged by sunlight in a day. The lantern can be illuminated for 8 hours depending on the wattage of LED used.

 

Features:

 

      High reliability and durability
      Built in battery charger
      Maintenance free sealed gel battery with a life of minimum 1 year.
      Portable, compact, lightweight.
      LED based light.
      Over charge and deep discharge protection.
      Load short circuit protection.

 

Typical Applications:

           Offices
      Schools/Colleges
      Hospitals
      Rural residential Houses
      Industries/Factories
      Fishing Boats,
      Camping etc.

 

Dignity through Electricity Program

 

Bringing solar lighting to Millions of Homes is no easy task. It requires Herculean Resources that need to be raised form several sources. SNB invites Non-Governmental Organizations (NGO’s), Charitable and Social Welfare Groups and thousand of individuals and Corporate Companies to join this cause and fulfill their Social Responsibilies..

 

Donors can sponsor from a single home to several homes and even complete village clusters.
Make a difference and bring light to those in darkness and also breathe cleaner air tomorrow

Choose an option and see how you can change Lives:

 

 

       Help the Really Stretched Village Housewife to perform her daily chores better– Cooking, Stitching, Children and Home
        Management
      Help increase useful Hours of Village Family… With LED lighting their Day no longer will end at sunset
      Help the village Youth to get better education-Also applicable to villagers and their wives wanting to learn new skills after   
       working the day in the fields
      Help new village businesses to develop
      Help in improving personal safety specially during Monsoon Months
      Save some Million Tons of Carbon Dioxide from being added to the air a person breathe

 

See how your donation can help a Village:

 

    A single Solar Home Lighting System costing just Tk. 2500.00- (US$ 35) one time can bring
Light to a Village Home to help them live better

   A cluster of Homes sponsored will allow a Village Community to live better and improve living standards and also Income Levels.. Options in multiples of Tk. 25000.00 (US$ 348) and above

   A School Lighting System can allow at least 100 students or 100 villagers (Adult Education) to improve their educational levels… Options start at Tk. 15,000.00 (US$ 209)

   A Community Center allows some 200 villagers a better evening… Options start at Tk. 25,000.00 (US$  348)

   A Village Co-operative Center allow more business to be done... Options start at Tk. 35,000.00 (US$ 487)

   A Street Lighting System improves personal safety for 20 villages and allows some educational facilities… Options start at Tk. 35,000.00 (US$ 487)

   A set of 50 LED Torches (flash light) helps 50 Families to improve their personal safety.. Options start at Tk. 10,000.00 (US$ 139)

 

All costs are one time and include the cost of the system, free installation and free replacement parts for one year.