1 radovan kopecek, bifi pv psda, antofagasta (chile) 2015

Bifacial PV: one small step for technology, one giant leap for kWh cost reduction

Radovan Kopecek et al.

International Solar Energy Research Center (ISC), Konstanz, GERMANY

Radovan Kopecek, bifi PV PSDA Workshop, Antofagasta, 14-15 January 2015 2

THANKS!!!!


Summary of first day

- Chile has a huge potential

- but also great scientists and R&D

- that makes the cooperation between Germany and Chile extremely fruitful


Photovoltaics in 2014

feed in tariff in Germany

2014 CAPACITY: production 45GW, installed 48GW >> cumulative 187 GW, (60GW expected in 2015) COSTS: modules for 0.55-65€/Wp, systems for 1.20-1.40€/Wp >> in Germany: 8-10ct/kWh


“new bifacial history” and future

2000

2015

2020+

monofacial bifacialBIFACIAL!!

monofacial

- No albedo!!- Too expensive!>> NONSENSE

- up to 30% gain- save BOS>> FUTURE TECHNOLOGY

?

Radovan Kopecek, bifi PV PSDA Workshop, Antofagasta, 14-15 January 2015

bifiPV workshops and publications in 2014/2015

6


bifiPV workshop in May 2014

7


bifiPV workshop: STANDARTISATION

8


EUPVSEC in September 2014

9


PV international from December 2014

10


PV tech Blog 13th January 2015

11



12

We are very confident that bifaciality will become an extremely important technology, for the following reasons:

1) High-efficiency solar cell technologies are getting bifacial anyhow (passivated rear-side of advanced concepts make this possible);2) Many module producers are introducing or even completely switching to glass-glass modules (thin glass becomes cost effective and glass-glass leads to longer lifetime of a module);3) Balance of system (BOS) costs are approaching a level that is hard to be further reduced and consequently high power modules (smaller area of system lead to lower costs) are the only way to achieve a further reduction of the total system cost.



13

In order to reach the same energy yield (kWh/kWp) as a bifacial PV system based on modules with 20% efficient bifacial solar cells, operating with a bifacial gain of 15%, a standard monofacial PV system requires the use of expensive 23% efficient monofacial solar cells.



14

Advanced c-Si solar cell technologies with boron back surface field or emitter offer the possibility of making and using these devices in bifacial mode. In other words, future technologies (based on p- and n-type Si) exceeding 20% efficiency will be or can be easily made bifacial.



15

The largest enemy of bifaciality is the old-fashioned “Wp thinking” of customers instead of a modern “kWh mentality”.


Industrialisation with MegaCell/MegaGroup in

2014/2015

16


ISC and MegaCell/MegaGroup

Italy 2014/2015

Egypt 2015

Chile2015/2016


MegaCell/MegaGroup

18


MegaCell/MegaGroup

19


ISC and MegaCell: ITALY

20

• set up of 80MW cell and R&D factory• first BiSoN out in March 2015 (ZEBRA end 2015)>> education and creation of green jobs


ISC and MegaGroup: EGYPT 2015

21

• installation of bifacial systems• set up of 120MW cell and module factory>> education and creation of green jobs


ISC and MegaGroup: EGYPT 2015

22


ISC and MegaGroup: CHILE 2015

23

• installation of bifacial systems• set up of module factory>> education and creation of green jobs


PV system in Atacama


daily energy production: N direction

27

P

tmonofacial 250W



P

tmonofacial 250W

monofacial 250W

daily energy production: N directionPV system in Atacama


P

tmonofacial 280W

monofacial 250Wmonofacial 280W



P

tbifacial 280W (e.g. BiSoN)

monofacial 250Wmonofacial 280W

bifacial 280W

up to 30% gain



bifacial gain in dependence of albedoPV systems world wide


P

t

daily energy production: E-W

bifacial 280W: east-west


energy same to monofacial 280W in N

bifacial 280W: east-west


P

t

daily energy production: E-W

bifacial 280W: east westsingle axis tracking

up to 50% gain


bifacial 280W: east westsingle axis tracking


lifetime energy productionstandard mc-Si versus BiSoN


- bifacial history

- bifacial present

- bifacial future

what is the goal of this presentation?

35


THANKS FOR THE PERFECT ORGANISATION!



history of glasses

monoclePV present



history of glasses

glassesPV future

monoclePV present



history of glasses

monoclePV present

glassesPV future

googlePV future



history of glasses

monoclePV present

googlePV future

star treckPV future

glassesPV future



history of glasses

monoclePV present

googlePV future

star treckPV future

glassesPV future

- high efficient- bifacial and - smart module

e.g.BOSCH, LG electronics,Sunpower, Meyer-Burger, Nexolon (Mission Solar,) MegaCell, Motech, …


bifacial history


bifacial present


THANKS FOR THE PERFECT OGANISATION!

http://www.solarbuzz.com/news/recent-findings/multicrystalline-silicon-modules-dominate-solar-pv-industry-2014

who rules the PV world in 2014



http://www.solarbuzz.com/news/recent-findings/multicrystalline-silicon-modules-dominate-solar-pv-industry-2014


BIFACIAL

bifacial

bifacial


ITRPV roadmap




40%

40%BIFACIAL

bifacial




40%

40%BIFACIAL

bifacial

sunpowerPanasonicSolarwindYingliPVGS LG electronicsNexolonMegaCellMotechMeyer-Burger

SolarwindbSolar3D Solar RCT (mc PERCT)


R. Kopecek et al., PV international, December 2014

bifacial n-type technologies


A

BCFD EG

2

1

34

n-type technologies in production 2014

7

8 910

11

5

6

H

I

SOLAR CELL PRODUCERSA sunpower (IBC) 1993B Panasonic (HIT) 1997C Solarwind (NN) 2005D Yingli (Panda) 2010E PVGS (EarthOn) 2011F LG electronics (Neon)2013G Misson Solar (Nexolon)H MegaCellI MegaGroupWAFER AND INGOTPRODUCERS1 SunEdison2 Norsun3 Pillar4 BOSCH5 FerroTec6 China7 GTAT8 Comtech9 Longi10 Solargiga11 M Setek… (non exhaustive list)


present n-type screen printed, “diffused” technologies

n-type technologies in 2014

R. Kopecek et al., PV international, December 2014


BiSoN: certified I/V measurement at Fraunhofer ISE CalLab

Area[cm2]

Isc[A]

Voc[mV]

FF[%]

Pmpp[W]

Eff[%]

239 9.4 652 79 4.841 20.25

− implied Voc ≈ 690 mV− room for even higher efficiencies with improved metalization (reduced

contact area and new metal pastes)

� Typical I/V parameters of a BiSoN solar cell


roadmap of BiSoN technology

high implied Voc > 690 mV:• high quality of the process and device design

• high emitter quality and its surface passivation

� significant room for improvements using current process sequence and equipment by various optimizations

50 μm fingers

fine line print

Jsc: 40.1 mA/cm2

20.6%

FF: 79.5%

20.8%

double print

improved FF

Voc: 660 mV

21.0%

reduced contact area,

improved metal pastes

Current status

η 20.3%

JSC 39.4 mA/cm2

VOC 652 mV

FF 78.9%


(e.g. Sunpower IBC, Panasonic HIT, ..)

ZE

BR

A-I

BC

Mo

du

les

(exp

ecte

d C

oO)

2013 Standard Module

High efficiency Module

MWT

Data from: Pvinsights, Photon, ITRPV 2013, Eurotron, owncalculations (CoO depending on location of manufacturing site)

Highest efficiencyHigh cost

High efficiencyLow cost

Sta

nd

ard

eff

icie

ncy

Low cost

sales price range (Q4/2014)

avg. estimated CoO

ZEBRA

CoO 60 cell modules

BiSoN


“standard bifi installation”: quantitative

58Dr. Radovan Kopecek, What is behind a solar cell?, June 2013

30°

white board

Conditions

- module embedded in black frame (1x0.5) m2

- placed on white board

- inclined by 30° and facing to the South

- measured in bifacial and monofacial (rear side

covered) arrangement

10 12 14 16 180,0

0,2

0,4

0,6

0,8

1,0

bifacial monofacial

Pm

pp [a

rbitr

ary

units

]

time during one day in August [h]10 12 14 16 18

20

30

40

50

60

70

80

average gain in P of 33%

time during one day in August [h]

gain

in P

[%]

outdoors measurement on roof of PV lab at UKON

(southern Germany)

bifacial modules: standard orientation

2002


LCOE for large systems in Germany

from 1GW study 2014, FHG IPA and ISE


bifacial BiSoN and ZEBRA cells

Cell type illuminationJSC

[ mA/cm2 ]

η

[ % ]

Pmax

[W]

Metallization area

[ % ]

front 39.3 20.1 4.8 6.3 ± 0.24

rear 34.7 17.6 4.2 7.7 ± 0.32

front 40.8 20.9 5 0

rear 30.5 n/a(15.6*) n/a(3.7*) 17.5 ± 0.64

IV measurements of best cells (front and rear side illumination):

- on a black coated chuck

*Estimated value assuming the same Voc and FF from front side illumination

ISC Konstanz, bifiPV workshop, 2014


bifacial BiSoN/ZEBRA mini-modules4 cells modules with transparent back sheet:

STC indoor measurements (25°C, 1 sun)

illuminationPmax

[W]

Prear/Pfront

(module)

Prear/Pfront

(best cell)

Front 17.68

0.88 0.87

rear 15.71

front 18.22

0.65* 0.75**

rear 11.84*

Front side photograph

Front side photograph

* with 4 mm wide ribbons (≈29% shaded area)** estimated from JSC(rear)/JSC(front)



outdoor test results of mini-modulesOutdoor test conditions of the 4-cells modules:

• ground reflectivity → ≈ 70% (300-1200nm) (white back sheet)

• orientation and inclination → South, 30°

• measurement interval → every 5 min. (10 sec. module measure time)

• all modules assumed to have the same temperature during an IV scan

• front glass taped black outside cell area

• one additional module was used to measured the back side light intensity

Photograph of the outdoor setup



One day yield comparisons (bifacial versus monofacial):

0.26

0.28

0.30

0.32

0.34

0.36

En

erg

y yi

eld

(W

h/W

p)

BiS

oN

bla

ck B

S

BiS

oN

tran

spar

ent

BS

ZE

BR

Ab

lack

BS

ZE

BR

Atr

ansp

aren

t B

S

+ 15.1%

+ 19.8%

08:00 10:00 12:00 14:00 16:00 18:005

101520253035404550 Bifacial gain:

BiSoN ZEBRA

Irradiance: Indirect/Direct

time (HH:mm)

(%)


outdoor test results of mini-modules


outdoor test results of 60 cell modulesresults from ISC‘s test site in el Gouna

Front (indoor): 298Wp

Outdoor total: 420Wp-e*

*peak effective power output


simulations with real data of bSolar

bSolar, bifiPV workshop, 2014

single module in el Gouna

real systems in el Gouna


the largest bifacial system


the largest bifacial system

PVGS, bifiPV workshop, 2014

>> even in not optimised system bifaciality offers large kWh increase


summary

69

- solar cells in near future will be bifacial anyhow

- many modules in future will be glass-glass

- the system kWh can be extremely increased by using bifacial cells and bifacial modules

>> bifacial systems have to be set up and the advantage monitored

>> measuring standards and good bifacial system simulations have to be introduced


Hosted by Linked to Conference Organization

March 23-26, 2015

1 radovan kopecek, bifi pv psda, antofagasta (chile) 2015

Presentations & Public Speaking

Transcript of 1 radovan kopecek, bifi pv psda, antofagasta (chile) 2015