From Silicon to Electricity
SOLAR ENERGY PRESENTATION
From Silicon to Electricity
01 Fundamentals
Which market to enter?
Which customers to target?
02 Silizium
Production
03 Wafer
Optical comparison / differences
Technical advantages /disadvantages
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Production steps in the
factory
Production steps, broadly defined
„Dirty Production“
Possible factory layouts
Typical machinery / equipment
05 Solar panel
Panel manufacturing / Basic structure
06 Feeding in electricity
07 Inverters
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The Market
The target group defines the wafer quality
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Home owners
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Commercial investors
– Major real estate
– Solar farms
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Public entities
 reasonably priced purchase and maintenance / simple
installation
 Longevity / outstanding performance / simple exchange
of faulty units / safe monitoring
(remote)
 Longevity / outstanding performance
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Silicon Production
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Silicon is a metalloid.
The production of silicon (high-purity silicon) is very energy consuming. This makes it
crucial to decide if this production step is outsourced or not. It is a process belonging to
the area of „dirty“ production.
The choice of silicon production depends on the desired result and the intended quality of
the panel. ( multi crystalline / mono crystalline = thick layer cells)
Further option „thin layer cells“ (String ribbon – to be carefully considered, since
performance is significantly lower than with thick layer cells)
Amorphous solar cells (silicon on a backing layer, like glas)
Switching from one quality to another is costly and time-consuming.
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Silicon Production
Silicon ingot
(monocrystalline)
Silicon production, String
ribbon (Source: Evergreen)
Silicon ingot (multi
crystalline)
Alternatively string ribbon
can be produced by the so
called octahedron process.
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Wafers - Comparison / Differences
Multi
crystalline
Mono
crystalline
Standard sizes:
125mm x 125 mm
156mm x 156 mm
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Multi crystalline:
Squarish shape, „snow flake surface“,
Mainly used for solar panels
Mono crystalline :
Rounded corners, since made from
rounded ingots, uniform surface texture,
used only for prime quality solar panels
because of high production cost
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Technical (Dis)Advantages
Wafer type
Advantage
Disadvantage
String ribbon
Nearly no waste
Low performance
String ribbon
Comparatively cheap
production
Very special production process
Multi crystalline
Cheaper than mono
crystalline
Good energy efficiency
Multi crystalline
Ingot production is simpler
than for mono crystalline
wafer
Less energy efficiency than a
mono crystalline wafer
Amorphous
Suitable for diffuse light
Low energy efficiency
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Production steps in the factory
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Production steps, broadly defined
„Dirty Production“
Possible factory layout I
(Solar wafer production)
Possible factory layout II
(Panel production)
Examples for manufacturing plants
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Production steps, broadly defined
„Dirty Production“
Clean room production
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Silicon block production
Sawing the blocks into bricks / ingot size
Sawing the ingot (multi / mono) to wafer
thinness
Cleaning the wafer (removal of slurries)
Separating the wafers (critical process 
possibly high percentage of breakage)
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Etching off the saw damage ( so-called etching
machine or edge isolation)
Doping (phosphorous doping in the oven)
Second etching (removal of phosphosilicate
glass)
Applicating the antireflection layer PECVD 
Plamas process (costly – complex  possibly to
be replaced by used material)
Lithography (screen print)
Welding of strings
Production of panels
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„Dirty Production“
Wafer is sawn from the ingot
Saw slurry removal by water (with additives)
Milky water = Water with slurry
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Possible Factory Layout I (Solar wafer
production)
Production steps in clean
manufacturing.
From the clean, etched wafer
to the classified wafer going
into string production.
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Possible Factory Layout II (Panel production)
From solar cell to solar
panel - This is a fully
automatic production
line, but steps could be
done manually without
quality loss.
Source: XINOLOGY
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Production Plant Example
Saw damage etching incl. assembling
Chemical process.
Warning: the chemicals involved
for all processes are waterpolluting substances!
Bildquelle RENA
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Production Plant Example
Tube doping furnace
Doping furnace
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Flow doping furnace
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Panel Manufacturing
Solar panels have to fulfill a variety of requirements:
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Safety for the user with regard to:
Electrical safety
Mechanical safety
Easy handling ( by handling technology / application technology / mounting aid)
Robustness can be achieved by:
Protecting the panel from mechanical and thermic stress
Protection against dampness.
Durable electric connections
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Production Steps
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Solar panel construction
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Feeding in electricity
Additional requirements:
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Inverter (one for a previously defined number of panels or pre-defined feed-in
power).
Inverters are produced at reasonable prices, one should consider a franchise or
cooperation.
Feed-in tariffs (taking into account that the house is not self-sufficient with regard
to energy – electricity is taken from and fed back into the electricity grid)
Remote access to electricity production (important for commercial energy farms)?
To handle a multitude of minor and major feed-ins the area needs so-called „smart
grids“.
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Inverters – Basic Facts
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There are different kinds of inverters, ranging from photovoltaic and UPS (Uninterruptible
Power Supply) to lighting (e.g. ballasts for fluorescent lamps)
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Solar inverter:
A solar inverter converts the direct current produced by the solar cell into alternating voltage.
Only alternating voltage can be fed into the grid.
There are different kinds of solar inverters. The choice depends on the technical requirements.
From a technical viewpoint the difference lies in choosing an inverter with or without
transformer. Those without transformers have a higher efficiency.
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Inverter Production
Required production units:
• Circuit board manufacturing (Lamination)
• Circuit board manufacturing (Manual or automatic assembly, welding by reflow furnace.
Manual welding is possible, but not recommended) and testing the finished circuit boards
• Case production
• Final mounting – (circuit boards into casing)
• Calibration / software installation on the end device (may be done while testing the circuit
boards)
• Functional check
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GETS
1164 St., Building Number 5
kontech GmbH
Morabaa El Wozara,
Byk-Gulden-Straße 18
Masaken Sheraton
Cairo ::: Egypt
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0049-7731-9871-0
D-78224 Singen
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