Identification of Technical Risks in the PV Value Chain and Quantification of the Economic Impact on the Business Model

Transcription

1 32 nd EU-PVSEC, Munich, Germany 5.DP June 2016 Identification of Technical Risks in the PV Value Chain and Quantification of the Economic Impact on the Business Model David Moser Matteo Del Buono, Ulrike Jahn, Magnus Herz, Mauricio Richter, Karel de Brabandere Funded by the Horizon 2020 Framework Programme of the European Union

2 Disclaimer What you will not learn today - What is the best module or inverter manufacturer? - How does a PV plant of a specific market segment perform in specific climatic conditions? - How can I mitigate failures? (keynote presentation next year?) What you will (hopefully) learn today - Methodology to assess the economic impact of failures during operation and maintenance (cost FMEA applied to the PV sector) - Analysis from a database of failures collected in the field - The need for standardisation in failure collection and creation of failure database EU PVSEC

3 Project Overview European Union Horizon 2020 Work Programme 24 months (March 2015 February 2017) 5 consortium partners: Main Objective: Develop and establish a common practice for professional risk assessment which will serve to reduce the technical risks associated with investments in PV projects. Solar Bankability EU PVSEC

4 Modules O&M INTRODUCTION ON TECHNICAL RISKS TASK13: Review of Failures of Photovoltaic Modules, M. Köntges et al Failure description Failure mechanisms and detection Performance loss Failure statistics <2 years* Failure statistics after 8 years** *D. DeGraaff, et al, Presentation at PV Module Reliability Workshop, NREL, Denver, Golden, USA, (2011) Solar Bankability **A. Richter, 8. Workshop "Photovoltaik-Modultechnik", 24/25. November 2011, TÜV Rheinland, Köln 4

5 Modules O&M INTRODUCTION ON TECHNICAL RISKS % of modules returned (5 years of average deployment time, 3 million module years*) 1) 66% problems with laminate cell/ribbon/solder failures 2) 20% problems with backsheet or encapsulant - Degradation of modules dominated by a loss of short circuit current (discolouration and/or delamination)** Majority of returns associated with failures that can be detected visually (underestimation of other type of failures?) Systematic use of visual inspection Large dataset of failures * Hasselbrink et al, 2013 **Jordan et al, 2013 Solar Bankability 5

6 Inverters O&M INTRODUCTION ON TECHNICAL RISKS First results based on inverter replacements since 2010Q1 (population: inverters) Data from monitored plants Solar Bankability General Meeting 2 Sep 2015 Cologne DE 6

7 Inverters O&M INTRODUCTION ON TECHNICAL RISKS Replacement rate - initial phase of bathtub curve Solar Bankability General Meeting 2 Sep 2015 Cologne DE 7

8 How to assess Technical Risks: Risk Matrix Product Development Assessment of PV Plants Product testing Planning Transportation / installation O&M Decommissioning Modules..... Insulation Inverter test Soiling.. Module mishandling. Hotspot.. Undefined product Incorrect cell Shadow diagram (glass breakage) Delamination recycling procedure soldering Mounting structure Modules. mismatch. Module mishandling. Glass breakage.. Undersized bypass Modules not certified (cell breakage) Soiling diode Connection & Flash report. not. Module mishandling. Shading.. Junction distribution box boxes available or incorrect (defective backsheet) Snail tracks adhesion Special climatic Incorrect connection Cell cracks Delamination Cabling at the conditions. not. of modules. PID.. edges considered (salt Bad wiring without Failure bypass diode Arcing Potential spots on equalization the corrosion, &. ammonia,. fasteners List of. failures and junction. box. module grounding, LPS...) Visually detectable Incorrect assumptions junction box hot spots Weather station, of module... Theft of modules.. Incorrect communication, power rating (flash monitoring test issue) degradation, light induced degradation Module degradation Slow reaction time for Uncertified unclear warranty claims, vague components Infrastructure or & Module quality. unclear.. or inappropriate.. production environmental line influence (lamination, soldering) definition of procedure Storage system Simulation parameters for warranty claims (low irradiance,... Spare modules. no. Miscellaneous temperature.) longer available, costly unclear,. missing PAN.. string reconfiguration.. files Solar Bankability 8

9 Technical Risk Matrix Product Development Assessment of PV Plants Modules. Insulation test.... Inverter Incorrect. cell soldering.... Mounting structure Undersized. bypass diode.... Junction Connection &. box.... adhesion distribution boxes Delamination at the Cabling edges. Arcing spots on the.... Potential equalization & module..... Visually detectable grounding, LPS Weather station, communication, monitoring Product testing List of failures hot spots Incorrect. power rating.... (flash test issue) Uncertified components or Infrastructure & production. line.... environmental influence Storage system..... Miscellaneous..... Uncertainty Solar Bankability 9

10 Technical Risk Matrix Product Development Assessment of PV Plants Planning Modules..... Soiling Inverter. Shadow. diagram... Modules mismatch Mounting structure. Modules. not certified... Flash report not Connection &. available. or incorrect... distribution boxes Special climatic conditions not Cabling. considered. (salt... corrosion, ammonia, Potential equalization &....). List of. failures.. grounding, LPS Incorrect assumptions of module Weather station,. degradation,. light... communication, induced degradation monitoring unclear Module quality unclear Infrastructure &. (lamination,. soldering). environmental influence Simulation parameters.. Storage system. (low irradiance,. temperature.)... Miscellaneous. unclear, missing PAN.. files.. Uncertainty Solar Bankability 10

11 Technical Risk Matrix Product Development Assessment of PV Plants Modules..... Module mishandling Inverter.. (glass. breakage). Module mishandling. Mounting structure.. (cell. breakage). Module mishandling. Connection &.. (defective. backsheet).. Incorrect connection distribution boxes of modules Cabling.. Bad. wiring without.. fasteners Potential equalization & grounding, LPS..... Weather station, communication, monitoring Infrastructure & environmental influence Transportation / installation List of failures Storage system..... Miscellaneous..... Precursors Solar Bankability 11

12 Technical Risk Matrix Product Development Assessment of PV Plants O&M Modules..... Hotspot Inverter... Delamination. Glass breakage. Mounting structure... Soiling. Shading. Connection &... Snail. tracks. Cell cracks distribution boxes PID Cabling... Failure. bypass diode. and junction box Potential equalization &.. List of. failures Corrosion. in the. grounding, LPS junction box Theft of modules Weather station,... Module. degradation. communication, Slow reaction time for monitoring warranty claims, vague or inappropriate Infrastructure &... definition. of procedure. environmental influence for warranty claims Spare modules no Storage system... longer. available, costly. string reconfiguration Miscellaneous..... Quantifiable impact Solar Bankability 12

13 Technical Risk Matrix Product Development Assessment of PV Plants O&M Modules..... Hotspot Inverter... Delamination. Glass breakage. Mounting structure... Soiling. Shading. Connection &... Snail. tracks. Cell cracks distribution boxes PID Cabling... Failure. bypass diode. and junction box Potential equalization &.. List of. failures Corrosion. in the. grounding, LPS junction box Theft of modules Weather station,... Module. degradation. communication, Slow reaction time for monitoring warranty claims, vague or inappropriate Infrastructure &... definition. of procedure. environmental influence for warranty claims Spare modules no Storage system... longer. available, costly. string reconfiguration Miscellaneous..... Indirect impact Solar Bankability 13

14 Classification of technical risks Product testing Product Development Planning Transportation / installation Assessment of PV Plants O&M Decommissioning Risk Matrix Quantifiable impact Year 0 risks Uncertainty Precursors Indirect impact Solar Bankability 14

15 Quantification of economic impact of technical risks Risks to which we can assign an uncertainty (e.g. irradiance, degradation) Variance and uncertainty Link to financial probability parameters Risks to which we can assign a CPN (e.g. module and inverter failure) Failure collection and CPN table CPN value is an indication of preventive and corrective O&M (Euros/kWp/year) Solar Bankability 15

16 Planning O&M Quantification of the economic impact of technical risks Typical uncertainty values: 5-11%* 6-8%** Utilisation positively affected by reduction in uncertainty Link with business models and LCOE calculation >5% difference in yield at P90 *Reich, N., et al On-site performance verification to reduce yield prediction uncertainties, Solar 2015 Bankability PVSC IEEE 42nd **Richter, M, et al Uncertainties in PV Modelling and Monitoring. 31 st EUPVSEC

17 Yield [normalised value] Yield [normalised value] Planning O&M Calculation of uncertainty Risks to which we can assign an uncertainty (e.g. irradiance, degradation, temperature coefficients, etc) 120 Development of Risk scenarios Years Years Solar Bankability 17

18 Planning Quantification of the economic impact of technical risks Effect Overall uncertainty range (1 STD) Insolation variability POA transposition model ± 4-7% (see 5.1.1) ± 2-5% (see 5.1.1) Temperature coefficients and temperature effects ± 0.02%/ o C (5% relative error for crystalline silicon based modules) (lab measurements) Temperature deviation due to environmental conditions 1-2 o C (± 0.5-1%) (see 5.1.3) Up to ±2% if environmental conditions are not included How to reduce uncertainty? PV array and inverter model ±0.2% to ±0.5% (see 5.1.3) (up to 2% with e.g. PVsyst -> Mpp tracking and temperature dependency,) Degradation ± % (see 5.1.2) Shading Site dependent Soiling ± 2% (see 5.1.3) (Also site dependent) Spectral Missmatch (modelled) ± 0.01% - 9% (depending on PV technologies) 1 ± 1% for c-si Nominal power Up to ± 2% Overall uncertainty ± 5-10% 18

19 Quantification of economic impact of technical risks Risks to which we can assign an uncertainty (e.g. irradiance, degradation) Variance and uncertainty Link to financial probability parameters Risks to which we can assign a CPN (e.g. module and inverter failure) Failure collection and CPN table CPN value is an indication of preventive and corrective O&M (Euros/kWp/year) Solar Bankability 19

20 O&M Procedure for the calculation of CPNs Risks to which we can assign a CPN (e.g. module and inverter failure during O&M) a) Economic impact due to downtime and/or power loss (kwh to Euros) - Failures might cause downtime or % in power loss - Time is from failure to repair/substitution and should include: time to detection, response time, repair/substitution time - Failures at component level might affect other components (e.g. module failure might bring down the whole string) b) Economic impact due to repair/substitution costs (Euros) - Cost of detection to account for various techniques (IR for hotspots, EL for crack cells, Visual inspection, monitoring systems, etc) - Cost of transportation of component - Cost of labour (linked to downtime) - Cost of repair/substitution Solar Bankability 20

21 O&M Procedure for the calculation of CPNs Risks to which we can assign a CPN (e.g. module and inverter failure during O&M) 1. calculation of average downtime for a specific failure (h/failure) t down,fail =(t td + t tr/ts ) x PL x M + t fix x M PL = Power loss in % M = Multiplier to take into account impact at higher component level Failures Time to detect [h] Time to repair/substitution [h] Repair/substitution time [h] Power loss [%] Multiplier Hotspot ,00% 1 Delamination ,00% 1 Glass breakage ,00% 1 Soiling ,01 10,00% 1 Shading 8760 months 744 0,01 days10,00% hours 1 Snail 0 track ,00% 1 Cell cracks ,00% 1 Defective backsheet ,00% 1 Overheating junction box ,00% 1 PID = Potential Induced degradation ,00% 1 Failure bypass diode and junction box ,00% 1 Corrosion in the junction box ,00% 1 t t tr /t ts t EVA discoloration 8760 fix td ,0% 1 Theft of modules ,5 100,00% 1 Solar Bankability 21 Broken module ,00% ,00% 1

22 O&M Procedure for the calculation of CPNs Risks to which we can assign a CPN (e.g. module and inverter failure during O&M) n fail n comp Component Failures No. Tickets No. Cases No. Components Modules Delamination Modules Cell cracks Modules Snail track calculation of total downtime for the n number of components failures (h) t down = t down,fail x n fail 3.calculation of total downtime normalised by components (h/component) t down,comp = t down /n comp 4.calculation of occurrence over a time t ref (%) O = t down,comp /t ref t ref could be either the equivalent hours (specific yield), the total number of hours per year or the number of sun hours. Solar Bankability 22

23 O&M Procedure for the calculation of CPNs Risks to which we can assign a CPN (e.g. module and inverter failure during O&M) 5. calculation of production losses, L, due to downtime (kwh) L = O x S The severity, S, is calculated as the total plant(s) production over one year 6.calculation of downtime costs as missing production/savings C down = L x (FIT+PPA+RCE) For the calculation of the costs due to downtime, it is important to consider the missing income of feed in tariffs, the missing income from PPA, and/or the missing savings generated by PV plants installed on roofs/facades. RCE:Retail Cost of Electricity Methodology allows for geographical analysis and differentiation for PV plant typology and market segment Solar Bankability 23

24 O&M Procedure for the calculation of CPNs Risks to which we can assign a CPN (e.g. module and inverter failure during O&M) Methodology allows for the inclusion of the cost of detection C det t td Failures Rm (average cost of Rsu (average substitution cost Rr (average repair Rp (average transport costs per C detection/component) det C [ ] /component or unit) sub [ ] cost/component) [ ] component) C[ ] transp Hotspot 0,00 108,00 0,00 10,00 Delamination 0,00 108,00 0,00 10,00 Glass breakage 0,00 108,00 0,00 10,00 7. The costs related to fixing the failure results from the sum of the costs of repair/substitution, costs of detection, costs of transport and cost of labour Soiling 0,00 0,00 0,26 10,00 Shading 0,00 0,00 0,08 10,00 Snail track 0,00 108,00 0,00 10,00 Cell cracks 0,00 108,00 0,00 10,00 C fix = (C det + C rep/sub + C transp ) x n fail + C lab x t fix x n fail C rep Defective backsheet 0,00 108,00 0,00 10,00 Overheating junction box 0,00 108,00 0,00 10,00 PID = Potential Induced degradation 0,00 108,00 0,00 10,00 8. The calculation of the Cost Priority Number is then given by CPN = C down + C fix Failure bypass diode and Solar Bankability 24 junction box 0,00 108,00 0,00 10,00

25 Technical Risks collection CPN = C down + C fix O&M CPN is given in Euros/kW/year It gives an indication of the economic impact of a failure due to downtime and investment cost Tickets from O&M operators as corrective or periodic maintenance in paper or electronic form Visual and detailed inspection Solar Bankability 25

26 Technical Risks collection CPN = C down + C fix O&M CPN is given in Euros/kW/year It gives an indication of the economic impact of a failure due to downtime and investment cost Total number of plants Total Power [kwp] Average number of years TOTAL Components No. tickets No. Cases No. Components Modules Inverters Mounting structures Connection & Distribution boxes Cabling Transformer station & MV/HV Total Do all failures have a relevant economic impact? - Are data biased? Location / Technology / Monitoring system Biased site was surveyed due to a reported problem Unbiased site was surveyed as part of routine maintenance Extrapolated Only a part of the plant was surveyed and data extrapolated Solar Bankability 26

27 Definition of scenarios Never detected (CPN ndet ) Failure is undetected. Losses due to downtime over a time t td Failure fix (CPN failfix ) O&M 0 12 Failure is detected. 1 Month of lead time to repair/substitution t tr /t ts t fix t td Failures are equally distributed over time No increase in Performance Losses over time Yield is considered as an average at national level (not site specific) The real scenario would be a combination of the two EU PVSEC

28 O&M Technical Risks collection: occurrence and CPN no. cases no. Years OccurrenceOccurrence/ components year Modules 678,640 2,058, % 12% Inverters 2,474 11, % 8% CPN Occurrence never failuredetected fixin % Module Failure share Soiling 23.4% Shading 16.8% EVA discoloration 11.6% Glass breakage 6.5% PID 5.0% Inverter Failure share Fan failure and overheating 21.8% Fault due to grounding issues 4.9% Inverter firmware issue 3.8% Burned supply cable and/or socket 2.2% Polluted air filter 3.3% Inverter pollution 1.5% Solar Bankability 28

29 O&M CPN results - Components and market segments PV modules All market segments ~60 Euros/kW/y Who bears the cost? Who bears the risk? 29

30 O&M CPN results - Comparison studies Worst scenario vs base scenario for modules (higher PL) ΣCPN ndet = ~ 11 Euros/kWp/y ΣCPN ndet = ~ 19 Euros/kWp/y 30

31 O&M CPN results - Comparison studies Affected components vs total components: CPN ratio Failures calculated over the whole database Failures calculated over the affected plants EU PVSEC

32 O&M CPN results - Comparison studies Influenced components vs total components Defined as CPN ratio 0.08 /kwp/y 34 /kwp/y 6 /kwp/y 114 /kwp/y High CPN ratio for product failures or non technical factors EU PVSEC

33 Risk Evaluation of mitigation measures ΣCPNs = 120 Euros/kW/y 100% Intervening emergencies Minimizing downtimes Optimizing yield Guaranteeing performance Risk minimization 3rd Party Controlling ΣCPNs = XX Euros/kW/y 0% 33

34 Risk CAPEX OPEX Risk CAPEX OPEX Evaluation of Mitigation Measures Component testing, design verification, construction monitoring O & M, performance monitoring 100% ΣCPNs = ~ 120 Euros/kW/y 100% Who bears the cost? Who bears the risk? Risk minimization ΣCPNs = ~ XX Euros/kW/y 0% 0 /kwp 0 /kwp/a 0% 0 /kwp 0 /kwp/a CAPEX & OPEX depending on mitigation measures CAPEX & OPEX depending on mitigation measures 34

35 Outlook - Identification and quantification of mitigation measures during planning and during operation and maintenance (risk ownership) - Increase the portfolio with data collection for higher granularity (market segment, location, PV plant typology, climatic conditions, etc) - Assess the impact of the technical risks on business models on real cases - Assess the impact of uncertainties in the LCOE calculation (how can we reduce uncertainty?) - Assess the impact of technical risks on the initial yield assessment and long term yield assessment analysis Speaker Name Title of presentation 35

36 Project Reports Solar Bankability Workshop May 2016 Cologne DE 36

37 Acknowledgments EURAC would like to acknowledge: for their contribution to the database Speaker Name Title of presentation 37

38 Thank you PRESENTED BY David Moser This project has received funding from the European Union s Horizon 2020 research and innovation programme under grant agreement No The content of this report reflects only the author s view and the Commission is not responsible for any use that may be made of the information it contains Funded by the Horizon 2020 Framework Programme of the European Union

39 Product testing Quantification of the economic impact of technical risks deviations in 208 factory inspections average of 1.5 deviations per inspection Many deviations are related to determination of Pn (more than 20% of cases) Overestimation of output power is a problem Solar Bankability 39

40 Planning Quantification of the economic impact of technical risks Irradiance variability from various database Irradiance accuracy The Quality of Satellite-Based Irradiation Data for Operations and Asset Management 5AO.7.6 A. Woyte, K. De Brabandere, B. Sarr & M. Richter Solar Bankability 40

41 Planning Quantification of the economic impact of technical risks Uncertainty on degradation Environmental conditions and module temperature calculation Technical Risks in PV projects: Solar Bankability deliverable Solar Bankability 41

42 Planning Uncertainty Steps towards risk mitigation during planning Effect Overall uncertainty range (1 STD) How to reduce uncertainty? Through best practice Insolation variability ± 4-7% (see 5.1.1) POA transposition model ± 2-5% (see 5.1.1) - Probability distribution function of degradation rates Temperature coefficients and temperature effects ± 0.02%/ o C (5% relative error for crystalline silicon based - Check various models for the calculation of degradation modules) (lab measurements) - Understand the effect of high degradation tails to the Temperature deviation due to environmental conditions 1-2 o C (± 0.5-1%) (see 5.1.3) business models and LCOE Up to ±2% if environmental conditions are not included PV array and inverter model ±0.2% to ±0.5% (see 5.1.3) (up to 2% with e.g. PVsyst -> Mpp tracking and temperature dependency,) Degradation ± % (see 5.1.2) Shading Site dependent Soiling ± 2% (see 5.1.3) (Also site dependent) Spectral Missmatch (modelled) ± 0.01% - 9% (depending on PV technologies) 1 ± 1% for c-si Nominal power Up to ± 2% Overall uncertainty ± 5-10% Jordan et al, 2016 Volume 24, Issue 7 July 2016 Pages Solar Bankability 42

43 Propagation of technical risks Product testing Planning Transportation / installation O&M 7. Visually detectable hotspots - cells are overheating, which has a negative impact on the energy production of the module (module degradation). 1. Hotspot - overheating of cells etc. can cause burn marks. Temperature difference between neighbour cells should not be over 30 C. Infrared cameras can be used for imaging the defects of the modules. Hotspots can also identified by visual inspection from the rear side of the module. 8. Incorrect power rating (flash test issue) - sorting of the modules by performance will not be possible, PV modules mismatch losses undefined. High uncertainty of the nominal power of the PV plant and thus uncertainties of specific yield and performance ratio (PR). 3. Modules' mismatch - caused by interconnection of solar cells or modules without identical electrical properties or conditions (due to soiling, shadow, etc.). 5. Flash test report not available or incorrect - sorting of the PV modules not possible, mismatch losses undefined. unc unc 9. Uncertified components or production line - life cycle, reliability and quality of PV modules can be significantly reduced. 4. Modules not certified - no quality warranty, modules of unknown origin indir 8. Quality of module production unclear (lamination, soldering, etc.) indir 1. Soiling losses - less energy production due to soiling caused, amongst others, by pollution, bird droppings, and accumulation of dust and/or pollen. Its impact is strongly site dependent. 4. Soiling losses - due to operational conditions: e.g. smog, sand particles, bird droppings, etc. Its impact is strongly site dependent. Solar Bankability 43

44 CPN results - Components and market segments PV modules - Residential O&M Only failures detected by visual inspection most probably most of the PV modules, that belong to residential segment, have failures that have not been yet detected Solar Bankability General Meeting 3 Feb 2016 Bolzano IT 44

45 CPN results - Components and market segments Total Inverters O&M Highest risk is related to a group of installation failures Production losses are greater than the overall repair/substitution loss The same trend applies to the other market segments EU PVSEC

46 O&M CPN results - Components and market segments TOP 10 failures for all components EU PVSEC

47 CPN - Time & Cost Parameters Parameters t td t tr t fix PL M Failures Time to detect [h] Time to repair/substitution [h] Repair/substitution time [h] Power loss [%] Multiplier Hotspot ,00% 1 Delamination ,00% 1 Glass breakage ,00% 1 Soiling ,01 10,00% 1 Shading ,01 10,00% 1 Snail track ,00% 1 Cell cracks ,00% 1 Defective backsheet ,00% 1 Overheating junction box ,00% 1 PID = Potential Induced degradation ,00% 1 Failure bypass diode and junction box ,00% 1 Corrosion in the junction box ,00% 1 EVA discoloration ,0% 1 Theft of modules ,5 100,00% 1 Broken module ,00% 1 Damage by snow ,00% 1 Corrosion of cell connectors ,00% 1 Unsufficient theft protection ,00% 1 Improperly installed ,00% 1 Module damaged due to fire ,5 100,00% 1 Missing modules ,00% 1 Solar Bankability 47

48 CPN - Time & Cost Parameters Parameters LABOR COST ( /h) INVERTER COST ( /kw) TRANSFORMER COST ( /800kVA) 50,00 100, ,00 MODULE COST ( /W) PALLETE COST ( ) CLEANING COST ( /kw) TRIMMING COST ( /km 2 ) 0,50 150,00 1,20 50,00 Failures Rm (average cost of detection/component) [ ] Rsu (average substitution cost /component or unit) [ ] C rep C det C sub C transp Rr (average repair cost/component) [ ] Rp (average transport costs per component) [ ] Hotspot 0,00 108,00 0,00 10,00 Delamination 0,00 108,00 0,00 10,00 Glass breakage 0,00 108,00 0,00 10,00 Soiling 0,00 0,00 0,26 10,00 Shading 0,00 0,00 0,08 10,00 Snail track 0,00 108,00 0,00 10,00 Cell cracks 0,00 108,00 0,00 10,00 Defective backsheet 0,00 108,00 0,00 10,00 Overheating junction box 0,00 108,00 0,00 10,00 PID = Potential Induced degradation 0,00 108,00 0,00 10,00 Failure bypass diode and junction box 0,00 108,00 0,00 10,00 Corrosion in the junction box 0,00 108,00 0,00 10,00 EVA discoloration 0,00 0,00 0,00 0,00 Theft of modules 0,00 108,00 0,00 10,00 Broken module 0,00 108,00 0,00 10,00 Damage by snow 0,00 108,00 0,00 10,00 Corrosion of cell connectors 0,00 108,00 0,00 10,00 Unsufficient theft protection 0,00 0,00 0,00 0,00 Improperly installed 0,00 0,00 0,00 0,00 Module damaged due to fire 0,00 108,00 0,00 10,00 Missing modules 0,00 108,00 0,00 10,00 Solar Bankability 48