Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

12 mihailetchi ok

ZEBRA: bifacial IBC technology

  • Login to see the comments

12 mihailetchi ok

  1. 1. ZEBRA: bifacial IBC technology Valentin D. Mihailetchi, Andreas Halm, Corrado Comparotto, Severin Aulehla, Radovan Kopecek International Solar Energy Research Center e.V., Konstanz, Germany
  2. 2. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 Outline 2 General • Bifacial cells and modules • ISC Konstanz bifacial cell concepts • BiSoN: n-PERT cell technology • ZEBRA: IBC cell technology Indoor STC results (front vs. rear illumination) • IV data • Spectral Response • Comparisons, predictions, … • BiSoN and ZEBRA modules Outdoor test results • ZEBRA vs. BiSoN (IBC vs. n-PERT) Summary
  3. 3. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 3 n-type solar panels producers on the market: Producer Cell technology Cell efficiency Module efficiency SunPower IBC (Maxeon) >24% 21.5% Monofacial cells Panasonic HIT 22.0% 19.4% Bifacial cells Yingli n-PERT (Panda) 19.5% 17.1% Bifacial cells PVGS n-PERT (EarthOn) 19.5% 16.2% Bifacial cells and panels LG n-PERT (NeoN) 21.3% 18.3% Bifacial cells Bifacial cells and modules Screen printed metallization
  4. 4. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 4 n-type solar panels producers on the market: Producer Cell technology Cell structure SunPower IBC (Maxeon) Monofacial cells Panasonic HIT Bifacial cells Yingli n-PERT (Panda) Bifacial cells PVGS n-PERT (EarthOn) Bifacial cells and panels LG n-PERT (NeoN) Bifacial cells Bifacial cells and modules All (produced) bifacial cells have both sides contacts (BSC) !!
  5. 5. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 5 Is BSC the ultimate bifacial cell technology ? Bifacial cells and modules front side rear side
  6. 6. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 6 ISC’s bifacial cell concepts BiSoN (n-PERT) • BSC cell technology • n-type 6-inch Cz Si • homogeneous p+ and n+ diffusions • front side textured, rear side flat • IBC cell technology • n-type 6-inch Cz Si • homogeneous p+ and n+ diffusions • front side textured, rear side flat or textured ZEBRA (IBC)
  7. 7. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 7 ISC’s bifacial cell concepts BBr3 diffusion, p+ emitter POCl3 diffusion, n+ BSF Saw damage etching, alkaline texturization, cleaning steps SiO2/SiNx passivation & ARC Screen printing and firing of p and n fingers, busbars PECVD masking Laser ablation BiSoN (n-PERT) ZEBRA (IBC)
  8. 8. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 8 ISC’s bifacial cell concepts BiSoN (n-PERT) ZEBRA (IBC) What if both cell concepts cost the same (in €/Wp)?
  9. 9. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 9 IV data Cell type area [ cm2 ] JSC [ mA/cm2 ] VOC [ mV ] FF [ % ] h [ % ] Pmax [W] 239 39.4 652 78.9 20.3* 4.85 239 41.2 646 79.1 21.0 5.03 IV measurements of best cells (front side illumination): - on a reflective chuck *Independently confirmed by CalLab PV cells at Fraunhofer ISE
  10. 10. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 10 IV data Cell type illumination JSC [ mA/cm2 ] h [ % ] 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 Is ZEBRA cell concept interesting for bifacial applications? ?OK *Estimated value assuming the same Voc and FF from front side illumination
  11. 11. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 11 IQE data IQE measurements from front and rear side: 1. front side response: ZEBRA  BiSoN 2. rear side response: ZEBRA < BiSoN 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 BiSoN (front) BiSoN (rear) ZEBRA (front) ZEBRA (rear) IQE(-) Wavelength (µm)
  12. 12. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 12 Comparisons, predictions IV measurements of best cells (front and rear side illumination): ƞ rear / ƞ front = 75 %ƞ rear / ƞ front = 87.5 % 1. ZEBRA is the best for front side illumination 2. BiSoN has the best bifacial ratio BiSoN ZEBRA 15 16 17 18 19 20 21 Efficiency(%) rear illumination front illumination (5 W) (4.8 W)
  13. 13. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 13 BiSoN and ZEBRA modules STC indoor measurements (25°C, 1 sun) illumination Pmax [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* 4 cells modules with transparent back sheet: Front side photograph Front side photograph * with 3 mm wide ribbons (24% shaded area) ** estimated from JSC(rear)/JSC(front)
  14. 14. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 14 Comparisons, predictions Calculated modules performance with additional rear side illumination: 1. ZEBRA is as good as a dedicated bifacial module for rear side light intensities <0.3 sun. 2. ZEBRA has the advantage of generating more power in monofacial or at low albedo contributions 0.0 0.1 0.2 0.3 0.4 0.5 17 18 19 20 21 22 23 24 25 26 rear side light intensity (suns) 4cellsmodulepower(W) BiSoN, 2mm ribbons (Prear /Pfront =88%) ZEBRA, 3mm ribbons (Prear /Pfront =65%) ZEBRA, 2mm ribbons (Prear /Pfront =75%)
  15. 15. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 15 Comparisons, predictions Cells (or modules) fabrication: • can have asymmetric front/rear performance • should be optimized based on front side performance Reflected sunlight Direct sunlight Slanted Reflected sunlight Direct sunlight Horizontal Direct light Reflected light> Typical outdoor installation of a bifacial module: rear side irradiance ≤ 0.3 × front side irradiance !?
  16. 16. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 16 Outdoor test results Outdoor 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 ZEBRA black BS ZEBRA transparent BS ZEBRA (rear irradiance) BiSoN transparent BS BiSoN black BS ZEBRA (2) transparent BS
  17. 17. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 17 Outdoor test results 15-May-14 16-May-14 17-May-14 18-May-14 19-May-14 20-May-14 21-May-14 0 200 400 600 800 1000 1200 1400 Directirradiance(W/m 2 ) One sunny day chosen for modules comparison ! Outdoor test conditions of the 4-cells modules:
  18. 18. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 18 Outdoor test results Outdoor modules performance (bifacial versus monofacial): Module temp. at noon: 48°C !!! 1. Monofacial modules: ZEBRA = BiSoN 2. Bifaical modules: ZEBRA ≤ BiSoN 08:00 10:00 12:00 14:00 16:00 18:00 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 ZEBRA (transparent BS) ZEBRA (black BS) Bison (transparent BS) Bison (black BS) Direct irradiance (suns) Indirect irradiance (suns) time (HH:mm) Pmax /Pmax(STC) (-)
  19. 19. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 19 Outdoor test results One day yield comparison (bifacial versus monofacial): 0.26 0.28 0.30 0.32 0.34 0.36 Energyyield(Wh/Wp) BiSoN blackBS BiSoN transparentBS ZEBRA blackBS ZEBRA transparentBS + 15.1% + 19.8% 08:00 10:00 12:00 14:00 16:00 18:00 5 10 15 20 25 30 35 40 45 50 Bifacial gain: BiSoN ZEBRA Irradiance: Indirect/Direct time (HH:mm) (%) ZEBRA is a bifacial IBC technology !!!
  20. 20. Mihailetchi et.at., bifiPV workshop, Chambery, May 2014 20 Summary Best cell efficiency:  20.3%, n-PERT BiSoN  21.0%, IBC ZEBRA Bifaciality ratio (@ cell level):  87.5%, n-PERT BiSoN  75.0%, IBC ZEBRA Bifacial/Monofacial yield gain:  19.8%, n-PERT BiSoN  15.1%, IBC ZEBRA Acknowledgements: The project HERCULES has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement No 608498.

×