by Arvind Shah, Professor (Emeritus) at Neuchâtel University & EPFL – Founder of PV-Lab

« Thin-film silicon solar modules: a technology for the future»

In 1985, we founded the PV Lab Neuchâtel ,with the goal of lowering the production costs of solar cells. We chose to work on thin-film silicon, because of the following reasons (WHICH ARE STILL VALID): a)  Silicon is an abundant

material (constitutes 28% of the earth’s crust)

b)  Silicon is NOT a toxic material

c)  Thin-film silicon solar cells allow for reductions in cost and in production energy as compared to the conventional wafer-based silicon solar cells

Let us now look at the Development of Thin-film Silicon Modules in the past And Make from this Projections for the Future

Since 1975, amorphous silicon had been introduced by the group of Prof. Walter Spear as low-cost material for large-area applications, such as solar panels and displays.

Somewhere between Scotland and the USA

And they continue to talk

Around 1980: Chris Wronski and Dave Carlson of RCA Labs had introduced

the p-i-n solar cell structure, Yukinori Kuwano of Sanyo had made the first commercial amorphous silicon solar cells, for calculators  

1985 our group at IMT Neuchâtel started with just 3 members 1987 we introduced VHF high-rate plasma deposition 1993 we pioneered microcrystalline silicon as absorber layer 1994 we introduced the «micromorph» tandem solar cell

Light

amorphous silicon e

microcrystalline silicon n

Back Reflector (BR) e

amorphous silicon absorbs blue and green light

microcrystalline silicon absorbs red and infrared light

The «micromorph» solar cell Is a sandwich of a slice of amorphous silicon and a slice of microcrystalline silicon

1994-2006: the «micromorph» tandem solar cell is taken up by many Industries in the whole world (Switzerland, EU; USA; Japan; China,...)  

2003 IMT signed a licensing contract with OERLIKON 2007—2009 OERLIKON sold 20 production lines 2012 OERLIKON SOLAR became TOKYO ELECTRON SOLAR

Since 2012 TOKYO ELECTRON is selling the 2nd generation ThinFab™ achieving: •  Manufacturing cost of “micromorph modules” à € 0.35/Wp, •  Stabilized efficiency 10.8% •  154 Wp module performance (for ≈ 1.4 m2 total area)

àIt took almost 20 years from Lab Concept (1994) to real Production Line (2012)

The result is: Automated, Large-scale, High-cost High-Performance Equipment

1999-2009: Germany introduced Feed-in Tariffs for solar electricity, leading to a 4% share of PV current

2002-2009: China reduced fabrication costs for PV panels by 50%

2008-2009: World-wide financial crisis

In the Year 2009

Solyndra, a production unit for CIGS-type thin-film modules, was built with the support of a $535 million federal loan guarantee ;

it closed down in 2011

Solyndra, a Californian panel manufacturer abruptly ceased all operations on 31.8.2011

The largest manufacturer of flexible thin-film silicon solar modules, Uni-Solar, closed down in 2011

SHUT DOWN

On February 14, 2012, Uni-Solar, a Michigan-based solar panel manufacturer filed for bankruptcy

CLOSED DOWN

The Swiss manufacturer of flexible thin-film silicon solar modules, Flexcell/VHF-Technologies S.A.,

goes bankrupt in September 2012

Thin  Film  2012–2016:  Technologies,  Markets  and  Strategies  for  Survival  –  MJ  Shiao,  Senior  Analyst,  Solar  Markets  |  GTM  Research  

IN 2012 ALL TYPES of Thin-film solar cells have “gone crashing down” and with them the «micromorph» tandems

 

Module Price Trends

0.1  

1  

10  

1980   1990   2000   2010   2020   2030   2040  

Mod

ule  Price    in  USA

     $/Wp    

Year  

Séries1  

Expon.  (Séries1)  

Price  crash  due  to  overcapacity        

Module  Price    in  (USA)  $/Wp    

(not  corrected      for  infla4on)    

Price  increase  due  to  silicon  shortage        

Source:  1985-­‐2010  Data  from  Navigant  (Paula  Mints)  

In the future we expect module prices to increase again à 0.90 $/Wp for 2017-2020 At about 0.50 $/Wp module prices will reach a minimum level given by materlal costs      

LITTLE HOPE FOR THIN-FILM-SILICON? NOT TRUE!!

àFor special NICHE applications. We need flexible, low-weight, unbreakable thin-film panels

Here, heavy breakable conventional modules are being transported-- in a very precarious manner

Here, flexible, low-weight, unbreakable thin-film panels would be much better!

16

But what about Replacing Nuclear Energy by Photovoltaics ? (This would be a VERY large market for PV)

EXAMPLE OF SWITZERLAND In Switzerland today 60% of electric current is from hydroelectric power stations

40 % from Nuclear Reactors Nuclear Current should be replaced in 2034 by renewable energy §  Solar (photovoltaic) §  Wind §  Biomass, Geothermal

Harry  Truman  

Energy Payback Times (EPBT) (this is an aspect which will play an increasing role in the future)

2010

AssumpRons:    •  1700  kWh/  m2  solar  

radiaRon  (Southern  Europe)  

•  OpRmal  module  inclinaRon  

Source:  Mariska  deWild  Scholten,  European  PV  Conference  2011  

: u  Modules

produced with Chinese polysilicon à  slightly

higher EPBT values,

à  much higher carbon footprints

u  Future thin-film silicon modules with improved laminates

should have strongly reduced values of EPBT

Replacing Nuclear Electricity in CH by Renewables, by 2034: EXAMPLE OF SWITZERLAND Let us think of using Electricity from the Swiss Nuclear Reactors, to produce Swiss solar modules: 1.  Half of Nuclear to be replaced

by Wind, Biomass, etc.

àWith present Technology: NO problem at all!

2.  Other Half by Solar (PV) à With present c-Si PV Technology

(EPBT 4 years): we would need 20% of our Nuclear Current

à With future thin-film PV Technology (EPBT 0.4 years): we would need 2% of our Nuclear Current

2013-2017: we expect stabilization of the PV market à increase of module market prices by 10 t0 20%

à renewed interest in thin-film PV modules  

The Future

0.01  

0.1  

1  

10  

100  

1000  

10000  

100000  

1985   1990   1995   2000   2005   2010   2015   2020   2025   2030   2035   2040  PV  M

odule  Prod

ucvR

on  in  GWp  

Year  

Séries1  

Expon.  (Séries1)  

Annual  PV    Module    ProducRon  in  GWp      

ProjecRons  >2010:  EPIA  Scenarios  Global  Annual  New  Installed  PV  Capacity,  2000  to2015  

Module Production Trends

Global PV Production Capacity versus annual PV market

Almost  factor  2  overcapacity  

End  of  overcapacity:  2017  

Source:  EPIA:  “Global  Market  Outlook  for  Photovoltaics”  (published  June  2013)  

Conclusions •  Since 2009 PV module prices have crashed

–  (gone down by a factor of three) •  This is due to two effects:

–  Production capacity is twice as high as market volume –  World Financial Crisis

•  Until 2017 the situation will be stabilized, At 80 GWp market demand, 75 GWp prod. capacity and 0.90 $/Wp module price

•  At that moment thin-film modules will be very competitive, But their efficiency will always be lower and they will therefore be suitable for only a part of the applications

•  As we go over to replace Nuclear Electricity (partly) with PV, Production Energy (and Energy Payback Time) will become important Materials Availability will also be a decisive factor •  At that moment “micromorph” solar modules

will be again ONE OF THE WINNING TECHNOLOGIES

Conclusions for Greensolar (GS) à  There will definitely be a large market for GS-type equipment by 2015-2017 ü  Until 2015, the present small GS team can bring out record micromorph cells on a low-cost machine