Quantifying risk through a rigorous analytical approach to the real world challenge of offshore wind construction – downtime, constraints and sequencing. Nick Baldock Garrad Hassan and Partners Ltd

Contents  Problems Facing Offshore Wind Farm Construction  Garrad Hassan Approach  Validation Case Study  Conclusions  Summary

Risk Marginal economics Complex & costly Few EPC offerings Contractual interface risks Offshore Wind Farm Construction

Questions? Managing Contractors Capturing Project Restrictions Assessing Weather Delay Supply Chain Risks Optimal Vessel Strategies Time & Budget Contingency

Garrad Hassan Approach O 2 C (Optimise Offshore Construction) Model - Structure DEFINE OPERATIONS LONG-TERM WEATHER DATA TIME DOMAIN SIMULATIONS OPERATION DURATION DISTRIBUTIONS DEFINE SEQUENCE RULES DEFINE PROJECT DEFINE OTHER CONSTRAINTS DEFINE BUILD SEQUENCE MONTE CARLO ENGINE PERTURB SEQUENCE OPTIMAL SEQUENCE TOTAL DURATION DISTRIBUTION STAGE 1 STAGE 2

Stage 1 – Time Domain Simulations - Operation Duration Distribution - For each defined offshore operation - Monthly basis DEFINE OPERATIONS LONG-TERM WEATHER DATA TIME DOMAIN SIMULATIONS OPERATION DURATION DISTRIBUTIONS Monopile & Transition Piece Installation Ideal Duration 50hrs

Garrad Hassan Approach O 2 C (Optimise Offshore Construction) Model - Structure DEFINE OPERATIONS LONG-TERM WEATHER DATA TIME DOMAIN SIMULATIONS OPERATION DURATION DISTRIBUTIONS DEFINE SEQUENCE RULES DEFINE PROJECT DEFINE OTHER CONSTRAINTS DEFINE BUILD SEQUENCE MONTE CARLO ENGINE PERTURB SEQUENCE OPTIMAL SEQUENCE TOTAL DURATION DISTRIBUTION STAGE 1 STAGE 2

- Project Build Duration Distribution - For each defined activity sequence Weather Downtime Logistical Downtime Stage 2 – Programme Modelling & Optimisation DEFINE SEQUENCE RULES DEFINE PROJECT DEFINE OTHER CONSTRAINTS DEFINE BUILD SEQUENCE MONTE CARLO ENGINE PERTURB SEQUENCE OPTIMAL SEQUENCE TOTAL DURATION DISTRIBUTION Total Project Build Duration Distribution

Model Validation Case Study Egmond ann Zee Offshore Wind Farm

- Modelled Construction Operations: Monopile & TP Installation - Svanen (36 Units) Turbine Erection – A2SEA ‘Sea Energy’ (36 Units) Export Cable Installation (3 Units) Inter-Array Cable Installation (33 Units) Turbine Commissioning Wind Farm Reliability Testing Validation Case Study

Egmond ann Zee Case Study Stage 1 Results - Monopile Foundation Installation Duration Distributions (Single Unit per Trip) Duration [hrs] (March) Duration [hrs] (June) Duration [hrs] (September) Duration [hrs] (January) Iterations

Egmond ann Zee Case Study Stage 1 Results - Turbine Erection Duration Distributions (2 Turbine Units per Trip) Duration [hrs] (March) Duration [hrs] (June) Duration [hrs] (September) Duration [hrs] (December) Iterations

Egmond ann Zee Case Study Stage 2 Egmond ann Zee project definition - Segregated into 10 construction zones - Single contractor per zone at any one time - Construction sequence: 1. Foundation Installation 2. Sub-Sea Cable Installation 3. Cable Terminations 4. Wind Turbine Erection 5. Cable Testing 6. Wind Turbine Testing 7. Wind Turbine Commissioning

Egmond ann Zee Case Study Stage 2 Results - Monopile & Transition Piece Installation O2C Predicted P(50) Project Build Duration Egmond ann Zee Total Project Duration O2C Predicted P(90) Project Build Duration 4 Days P (50) P (90)

Egmond ann Zee Case Study Stage 2 Results - Wind Turbine Erection O2C Predicted P(50) Project Build Duration Egmond ann Zee Total Project Duration O2C Predicted P(90) Project Build Duration 65 Days P (50) P (90)

Egmond ann Zee Case Study Stage 2 Results - Wind Turbine Erection (without logistic downtime) O2C Predicted P(50) Project Build Duration Egmond ann Zee Total Project Duration O2C Predicted P(90) Project Build Duration 1 Day P (50) P (90)

Egmond ann Zee Case Study Stage 2 Results - Total Project Build Duration O2C Predicted P(50) Project Build Duration Egmond ann Zee Total Project Duration O2C Predicted P(90) Project Build Duration 38 Days P (50) P (90)

Egmond ann Zee Case Study Conclusions - Good level of agreement (weather downtime modelling) - Modelling of project zones results in artificial delay (Egmond) - Modelling as an EPC contract would result in a better agreement - Complete project build duration within model’s P(50) to P(90) limits

Summary The value of O 2 C Modelling - Allows resourcing sensitivity studies - Allows cost benefit analysis - Allows developer to assess & reduce contract interface risks - Importantly allows for a novel visualisation of the project build

Thank You for Your Attention Nick Baldock - Garrad Hassan Main Stand Hall 2. No Contact details: (UK) (UK) (France) References: Offshore Wind Farm Egmond ann Zee General Report,