Cooperation on O&M and Life Cycle Cost anali ithVtt ... · Cooperation on O&M and Life Cycle Cost...

Chalmers University of Technology

Cooperation on O&M and Life Cycle Cost l i ith V tt f llanalysis with Vattenfall

François Besnard, Chalmers, PhD student Thomas Stalin, Vattenfall, Senior Project Manager

Deep Sea Offshore Wind R&D Seminar21 January 2011

Trondheim, Norway


Outline

• Background• Model overview• Model description• Results• Limitations• Conclusions

Photo: Lina Bertling

Besnard, Stalin21 January 2011

1/18Deep Sea Offshore Wind R&D Seminar, Trondheim, Norway


Background (1)• Previous works from PhD project:

– Optimization of maintenance planning– Cost benefit study of vibration condition monitoring systemCost benefit study of vibration condition monitoring system– Optimization of condition based maintenance for blades

• Inspired by the literature, no real “inside” from industry• Lack of reliability, maintenance and cost data → Sensitivity analysis• Interesting but no feedback on “practicality” • Licentiate thesis at the end of 2009

• Thomas Stalin from Vattenfall shows his interest in getting involved in the project with the idea of a cooperation on life cycle cost and profit analysisproject, with the idea of a cooperation on life cycle cost and profit analysis for offshore wind farm




Background (2)Life cycle cost and profit analysis is a method to evaluate the economic of a y p y

project by considering all the costs over the lifetime and taking into account the value of money through time.

• Investment (CAPEX)• O&M (OPEX)• Incomes• Incomes• (Repowering)• Decommissioning

Applications:• Cost benefit analysis of a project Source: ”The economics of wind energy”, EWEA, 2009Cost benefit analysis of a project• Continuous evaluation of the economic value of a project• Analysis of O&M: Reliability/maintainability, maintenance strategies, design

i t t bilit t /i / i t t t



improvement, supportability, warranty/insurance/maintenance contracts


Background (3)

• What are the cost-efficient maintenance strategies for each failure modes/causes?• Alternative: Re design (reliability improvement redundancy)



• Alternative: Re-design (reliability improvement, redundancy)


Background (4)The basis for the LCC model is the ECN O&M tool implemented in Excel • Model forecasting yearly O&M costs• Certified by Germanischer LloydCertified by Germanischer Lloyd

Vattenfall bought a license in 2007• First case study for Horns Rev (Baudish, 2007-2008)• Multiple scenario analysis for comparison of wind farms, wind turbines,

vessels and accommodation (Baudish, 2010)• Extended to life cycle cost and profit analysis, and updated case study

Horns Rev (Stalin, Besnard, 2010)

The model was developed in parallel with the data collection and analysis for Horns Rev from work orders, SCADA data and interviews

Model ↔ Case study



Model ↔ Case study


M d l O iModel OverviewThe model focuses especially on the O&M phase:• Simple investment and decommissioning model• Simple energy yield model (based on capacity factor + availability)Simple energy yield model (based on capacity factor + availability)• Simple electricity price scenarios (incentive system + prognosis)

O&M cost structure:• Corrective maintenance• Service/Preventive maintenance Direct costs: Staff, material,

l/ i t• Retrofits• Catastrophic/serial failures• Fixed costs (administration t t ti logistic O&M facilities

vessel/equipment

Indirect costs: Revenue losses• Fixed costs (administration, transportation, logistic, O&M facilities,

insurance, maintenance contracts…)Insurance/Warranty/Maintenance contracts cover part of the costs




Model Description (1)Corrective maintenance:• Frequency maintenance events (repair, replacement, preparation)• Seasonal distribution (i.e. planning with condition based maintenance)( p g )• Maintenance procedure:

– Spare part logistic timeV l d i t d d ti f d i i– Vessels and equipment, and duration of use during repair

– Number of technicians– Repair times– Splitting activity

• Cost for the material and spare part• Applicable retrofit (defined in a similar way in a separate worksheet)Applicable retrofit (defined in a similar way in a separate worksheet)• Applicable Warranty/Insurance (spare part, vessels, production losses)



Data structured according to RDS-PP, VGB, 2007


Model Description (2)Vessel characteristics and costs:Vessel characteristics and costs:• Weather constraints (wind and waves)• Logistic and travelling times• MOB/DEMOB costs and daily rate• ClusteringThe accessibility is modeled as a waiting time depending on the weather y g p g

constraints. It is calculated based on wind and wave statistics

Preventive maintenance activities:Preventive maintenance activities: • Seasonal distribution• Duration• Staff, equipment,

General wind farm data (capacity factors/seasons, staff costs and working



( p y , ghours, number of wind turbines) and overhead costs


• Examples of some input data for corrective and preventive maintenancep




• Examples of data for pvessels and waiting time defined by a polynomial function




Model Description (3)The life cycle cost scenario:• Investment costs (development, installation, WTs, foundations, grid),

d i i i t WF lif tidecommissioning costs, WF lifetime• Real discount rate• Electricity price scenarios• Failure distribution for each corrective maintenance activity:

– Constant failure rate (cf. “failure description”)– Continuous improvement

+ RetrofitsContinuous improvement

– Renewal process with Weibull distribution– Alternative for flexibility: Defined for each year

• Service/preventive maintenance activities defined for each year• Service and corrective maintenance, contracted availability during warranty• Possibility to use historical costs (overwrite calculated costs)



Possibility to use historical costs (overwrite calculated costs)


Results• Cost distributions with/without

warranty and insurances• Cumulative income and costCumulative income and cost

Project performance indicators:• N t P t V l (NPV)• Net Present Value (NPV)• Internal Rate of Return (IRR)• Profitability Index (PI)• Break-even year• Levelized Cost of Energy (CoE)

• Remaining economic value• Possibility to focus on a specific year




• Examples of results fromExamples of results from O&M life cycle cost and profit, and total life cycle cost distributioncost distribution




LimitationsBasis model:Basis model:• Production losses during waiting time are underestimated (ECN OMCE*)• Only fixed transportation strategies (i.e. not depending on wind/wave

condition at failure) → Complex, need time-series and simulation tool to consider number of failures and weather prognosis *

• No constraints on availability of staff, vessel, spare part, equipment → Limited evaluation of supportability *

For LCC:For LCC:• Detailed investment costs and driving factors (depends on application)• Scenarios for material, staff and vessel costs• Risk analysis *• Impact of condition based maintenance assessed subjectively, or

estimated in a separated model *




Conclusions• A tool for life cycle cost and profit analysis with special focus on O&M

• A successful project thanks to a close cooperation between Vattenfall and p j pChalmers:– Mutual interests– Weekly meetingsWeekly meetings – Access to reliability and cost data (NDA)– Hard work on data analysis

→ Need for structured and automatized reliability and maintenance data collection (implementation in SAP system at Vattenfall) and training maintenance personnel

• Future case studies: Continuation Horns Rev, Lillgrund, Kentish Flats, Egmond aan Zee



g


Thank you for your attention!

Questions?




Contact Information

François BesnardFrançois Besnard

• Institutionen för Energi och Miljö • Avdelning för ElteknikAvdelning för Elteknik• Chalmers tekniska högskola• SE-412 96 Göteborg, Sweden

• [email protected]

• http://www.chalmers.se/ee/SV/personal/besnard-francois




Previous WorksReferences

• F. Besnard and L. Bertling, “An Approach for Condition-Based Maintenance Optimization Applied to Wind Turbine Blades”, IEEE Transaction on Sustainable Energy, 1(2):77-83, 2010

• F. Besnard and al., “An Optimization Framework for Opportunistic Maintenance of Offshore Wind Power System”, In Proc. of IEEE PowerTech 2009

• F. Besnard, J. Nilsson and L. Bertling, “On the Economic Benefits of using Condition Monitoring Systems forF. Besnard, J. Nilsson and L. Bertling, On the Economic Benefits of using Condition Monitoring Systems for Maintenance Management of Wind Power Systems”, In Proc. of PMAPS 2010

• F. Besnard, K. Fischer, L. Bertling, “Reliability-Centred Asset Maintenance – A step towards enhanced reliability, availability, and profitability of wind power plants”, In Proc. IEEE ISGT Europe 2010

• K. Fischer, F. Besnard, L. Bertling, “Reliability-Centred Maintenance Analysis Applied to Wind Turbines”, to be presented at EWEA 2011presented at EWEA 2011

ECN O&M and OMCE Tools• L.W.M.M. Rademakers and al., “Tools for Estimating Operation and Maintenance Costs of Offshore Wind Farms:

State of the Art”, In Proc. of EWEC 2008• L W M M R d k d l “O ti d M i t C t E ti t Fi l t” T h i l t ECN E• L.W.M.M. Rademakers and al., “Operation and Maintenance Cost Estimator – Final report”, Technical report, ECN-E-

-09-037, 2009

Life Cycle Cost Analysis and Economics of Wind Energy• “Guide to Cost Benefit Analysis of Investment Projects”, Technical Report, European Union Regional Policy, 2008• “A Guide to an Offshore Wind Farm”, Technical Report, The Crown Estate, 2010• “The Economics of Wind Energy”, Technical Report, EWEA, 2009• “UK Offshore Wind: Charting the Right Course – Scenarios for offshore capital costs for the next five years”,

Technical Report, Garrad Hassan, 2009• “Offshore Wind Assessment for Norway” Technical Report Douglas Westwood 2010



• Offshore Wind Assessment for Norway , Technical Report, Douglas Westwood, 2010• “Offshore Wind in Europe - 2010 Market Report ”, Technical Report, KPMG, 2010

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