POLY Q.ANTUM VS. POLY PERC
PERC TECHNOLOGY
LETID CONTROL
In traditional BSF (Back Surface Field) solar cells some charge carriers
and light, especially in the infrared, are lost to the metallisation at the
rear of the cell. With PERC (Passivated Emitter Rear Cell) technology
material is added to the rear of the cell so that the otherwise lost charge
carriers and light are reflected back into the silicon.
LeTID (Light and elevated Temperature Induced Degradation) requires
both light and high temperatures to occur and progress. Hanwha
Q CELLS investigations into LeTID revealed that this degradation mode
is present in most crystalline silicon cells, however is only significant
in those which have experienced additional manufacturing processes.
PERC cells additional processing steps are what can cause LeTID to be
expressed more intensely, when not actively being controlled.
0,7
0,5
0
0,4
-2
0,3
Poly BSF
Poly Q.ANTUM
0
300
400
500
600
700
800
900
Wave Length (nm)
1000
1100
1200
Figure 1: Spectral Response. Energy conversion at different wave lengths for
PERC and BSF solar cells
-4
Q CELLS Warranty
Q.ANTUM
LeTID cell - 60°C Test
LeTID cell - 85°C Test
-6
-8
-10
-12
0
This design has two advantages over traditional BSF cells, reflection of
charge carriers and reflection of light. The reflection of charge carriers
increased power generation of the cell under all conditions, however
the reflection of light specifically improves the power generation from
longer wave lengths of light, namely infrared [> 1000 nm], and adds a
noticeable improvement to the performance under typical real world weak
light conditions. This advantage comes from the movement to longer,
redder, wavelengths of light falling on the cells at sunrise and sunset.
In standard test conditions PERC cells are around 4 % more efficient
than traditional BSF cells, in terms of a 60-cell solar module this is
over 10 W.
Q.ANTUM TECHNOLOGY
Hanwha Q CELLS has been developing its Q.ANTUM technology since
2009, and whilst PERC techniques form a vital part of what makes
Q.ANTUM different, it is one of a family of technologies which makes
it stand out. Anti LeTID, Anti PID, Hot-Spot Protect, Tra.QTM and Quality Tested all come together to form Q.ANTUM and provide the most
powerful, long lasting, stable and secure modules.
250
500
Test Hours (hrs)
250hrs test = ~1 year hot climate exposure
750
Figure 3: Typical, uncontrolled, LeTID of PERC cells vs. Q CELLS Warranty. Severe
degradation of up to 10 % observed in uncontrolled LeTID cells.
When not controlled LeTID presents as a single cycle, with losses in
module power of up to 10 % followed by increasing powers up to near
the original level. Due to its dependence on temperature conditions it
can take more than the lifetime of the solar module to complete this
single cycle. As part of Q.ANTUM technology Hanwha Q CELLS have
developed techniques to control LeTID which ensure stable module power
output within Hanwha Q CELLS performance warranty, and allowed for
the first gigawatt scale polycrystalline PERC manufacturing to take place.
ANTI PID
PID (Potential Induced Degradation) comes from a difference in electric potential between the encapsulated solar cells and the frame of
the module. In the worse cases PID can reduce module performance
Figure 4: Migrating electrons in PV module, the force behind PID
Figure 2: Additional “Power reflector” in Q.ANTUM solar cells
by 80 %. Hanwha Q CELLS started analysing the PID effect in 2008
and started to publish the PID effect in 2011, then in 2012 Anti PID
Technology was introduced on all Q CELLS products. Hanwha Q CELLS
understand the causes of PID in the field. Results from testing during
cell production, module production and from sites around the world
allow Hanwha Q CELLS to accurately model the PID effect, ensuring
secure yields in any environment.
Specifications subject to technical changes © Hanwha Q CELLS White Paper POLY Q.ANTUM vs. POLY PERC Cells_2017-03_Rev02_EN
0,2
0,1
Power Loss in Percent (%)
Spectral Response (A/W)
0,6
HOT-SPOT PROTECT
BENEFIT OF Q.ANTUM
The processing of silicon wafers can cause imperfections wich lead to
Hot-Spots. Typical hotspots contribute up to 5 % additional degradation
but in the worst cases hot-spots can lead to modules fires. Hanwha
Q CELLS tests every cell for potential Hot-Spots and removes effected
cells during cell production ensuring 100 % of modules are safe and
hot-spot free
Hanwha Q CELLS polycrystalline Q.ANTUM modules are available in
power classes up to 12 % greater than standard BSF modules. For a
residential roof top installation of 5 kWp this translates into 18 instead
of 20 modules, providing savings in installation labour and BOS costs.
At the heart of each and every Hanwha Q CELLS solar cell is Traceable Quality (Tra.QTM). This unique laser engraved matrix barcode not
only ensures original Hanwha Q CELLS quality, but allows every cell
EN
produced to be traced back though its entire lifetime from wafer to
field. Production information in this detail means Hanwha Q CELLS
can optimise production and raise quality using a level of detail not
found elsewhere in the PV industry.
Hanwha Q CELLS modules have first class energy yields even in low
irradiation environments, for example during sunrise and sunset, but
also in autumn and winter when the sun is flat over the horizon.
YIELD
TRA.QTM
Most crystalline solar modules suffer on hot days, but Hanwha Q CELLS
solar modules produce reliable yields and lose less efficiency than
standard solar with Pmpp temperature coefficient of -0.4 %/K.
Yield of Q CELLS
solar module 280 Wp with
Q.ANTUM technology
Better temperature
behaviour
12 % higher output
Yield of standard
module 250 Wp
Better low-light
performance
Morning
Noon
Evening
Figure 7: Benefits of Q.ANTUM Technology
Q CELLS QUALITY PROGRAM
Providing a warranty is one thing, delivering performance is another,
especially when considering that solar PV systems operate for at least
25 years. Despite the best warranty conditions, a solar PV system will
turn into a nightmare if modules need to be replaced on a regular basis.
Together with the VDE institute, Hanwha Q CELLS implemented the most
comprehensive quality program of the industry – VDE Quality Tested.
EN
VDE Quality Tested goes far beyond the minimum IEC and UL certification
requirements, extending the minimum test times, adding mechanical
load tests before climate chamber tests to more realistically simulate
real world stresses and lowers the allowed level of degradation caused
by these tests. After the initial certification tests Quality Tested then
continues with monthly retesting to guarantee consistent quality and
consistent product testing at all times.
EN
YIELD SECURITY
Quality Tested
 high reliability
 low degradation
 frequent
product surveillance
ID. 40032587
1.
Q CELLS Yield Security
2.
Initial certification tests
3.
VDE Quality Tested
4.
Q CELLS Quality Programme
ANTI PID TECHNOLOGY
(APT)
HOT-SPOT PROTECT
(HSP)
TRACEABLE QUALITY
(TRA.Q™)
Figure 6: Stages of Q CELLS Quality Program
Q CELLS ongoing quality program requires a 100 % EL inspection along
with minimum wet leakage, high pot, reverse current, grounding and
cross linking tests. Additionally to this modules are randomly selected
from production for complete in line re-inspection, damp heat tests,
mechanical loads, climate chamber and performance tests.
At Q CELLS quality means testing harder, continuously and more realistically to ensure only first class modules are shipped.
These factors in combination with positive sorting gives a first class
specific energy yield, which has been independently confirmed in the
harsh desert conditions at Alice Springs DKA, where Q.ANTUM powered modules show at least 1 % high specific yield than competitor
BSF modules.
EMAIL: [email protected]
TEL: +49 (0)3494 66 99 23222
Specifications subject to technical changes © Hanwha Q CELLS White Paper POLY Q.ANTUM VS. POLY PERC_2016-09_Rev01_EN
Figure 5: Close up of Q CELLS solar cells showing Tra.QTM marking