Description and contextualization of the subject

The module deals with the techniques commonly adopted for a safe design of offshore facilities, applied to the specific issues related to the deployment of offshore renewable energy arrays, focusing on operations and maintenance activities required throughout the lifecycle of the project.

The course will provide a wide perspective on main cost drivers of offshore renewable energy projects, focusing on the operational expenditure, the logistics requirements and planning for carrying out the operations at sea for the main subsystems (electrical cables, substations, mooring, foundations and offshore devices). The different maintenance strategies (corrective, preventive and predictive) will be defined and investigated. A probabilistic approach to maintainability and reparability will be used for the assessment of the reliability of the system. Approaches and concepts such as Fault Tree Analysis (FTA) and Failure Mode, Effects, and Criticality Analysis (FMECA) will be defined. The students will also learn methods for evaluating the site accessibility in time domain.

Four keynote lectures conducted by experts from Tecnalia R&I or other companies will complete the course. The topic of the lectures will depend on the availability of the instructors and they will tackle real operational experiences at sea, tools for designing offshore renewable energy devices and subsystems, novel offshore renewable energy technologies (as floating photovoltaic energy), advances towards the marketability of offshore wind projects, etc… A visit to a field site test facility (BiMEP) would complete the course, depending on weather or other restrictions.

Learning outcomes of the subject

After attending the course, the students will be able to:

1. Analyse the different phases of development of a offshore renewable energy array (installation, maintenance, decommissioning, etc.) and identify failure modes, operations and subsequent logistics requirements;

2. Estimating the reliability of a marine energy system;

4. Provide an estimate of the site accessibility and availability of the array;

5. Identity the main cost drivers for operation and maintenance activities and evaluate their impact in the assessment of the viability of the project

Ordinary call: orientations and renunciation

The assessment of the course during the ordinary examination period will be based on the proactive attendance of the course, an individual multiple choice exam and a final group presentation:

- The Class attendance and active participation will count for a maximum of 50% and a minimum of 30 % of the total mark.

- The individual multiple choice test will count for a maximum of 40% and a minimum of 20% of the total mark.

- The group assignment and presentation on findings from the keynote lectures will count for a maximum of 40% and a minimum of 20% of the final mark.

Extraordinary call: orientations and renunciation

The assessment of the course during the ordinary examination period will be based on the proactive attendance of the course, an individual multiple choice exam and a final group presentation:

- The Class attendance and active participation will count for a maximum of 50% and a minimum of 30 % of the total mark.

- The individual multiple choice test will count for a maximum of 40% and a minimum of 20% of the total mark.

- The group assignment and presentation on findings from the keynote lectures will count for a maximum of 40% and a minimum of 20% of the final mark.

Temary

4 Theoretical Lectures:

- Lecture 1 Introduction (2 hours)

- Lecture 2 Logistic Requirements, Cost Drivers and Maintenance strategies (3 hours)

- Lecture 3 Functional Decomposition and reliability of an offshore renewable energy system (3 hours)

- Lecture 4 Maintainability, reparability and accessibility of ocean energy arrays with applications (4 hours)

4 Keynote Lectures (according to the availability of the experts, 3 hours each)

Examples of potential topics

- The experience of the OPERA project: the real deployment of a wave energy project

- An open-sea offshore laboratory: HarshLab

- Design tools for the supporting the decision making process of an ocean energy array

- Floating offshore wind energy: trends and marketability

- Novel technologies at sea: floating photovoltaic energy

- A cost-oriented approach for the design of mooring systems

- ...

1 Visit at BiMEP (6 hours)

Bibliography

Basic bibliography

For general concepts about offshore structures:

• Chakrabarti, S.K., 2005a. Handbook of offshore engineering Vol. 1. Elsevier, Amsterdam

• Chakrabarti, S.K., 2005b. Handbook of offshore engineering Vol. 2. Elsevier, Amsterdam

For offshore wind turbine, for example

• Kaiser, M.J., Snyder, B.F., 2012. Offshore Wind Energy System Components, in: Offshore Wind Energy Cost Modelling. Springer London, London, pp. 13-30.



For ocean energy systems, for example

• Equimar Project, 2011. Sea Trial Manual (No. D4.1). Grant Agreement 213380.

For reliability issues

• Kapur, K.C., Pecht, M. (Eds.), 2014. Reliability Engineering. John Wiley & Sons, Inc., Hoboken, NJ, USA.

Offshore standards and recommended practice

• Det Norsk Veritas, 2011, Standard for Classification of Wind Turbine Installation Units, DNV-OS-J301

• Det Norsk Veritas, 2011, Modelling and Analysis of Marine Operations, DNV-RP-H103

More information about operations and maintenance

• V. Nava, P. Ruiz-Minguela, G. Perez-Moran, R. Rodriguez-Arias, J. Lopez-Mendia, and J.-L. Villate-Martinez, "Installation, operation and maintenance of offshore renewables," Renew. Energy Oceans Wave Tidal Gradient Syst. Offshore Wind Sol., pp. 397–424, Jul. 2019, doi: 10.1049/PBPO129E_ch11.

• Bengtsson, M., 2007. On condition based maintenance and its implementation in industrial settings. Maples, B., Saur, G., Hand, M., van de Pietermen, R., Obdam, T., 2013. Installation, operation, and maintenance strategies to reduce the cost of offshore wind energy. NREL Denver.

• Obdam, T., Braam, H., Rademakers, L., Van De Pieterman, R., 2011. O&M Cost Estimation & Feedback of Operational Data. INTECH Open Access Publisher.

• Rademakers, L., Braam, H., Obdam, T.S., vd Pieterman, R.P., 2009. Operation and maintenance cost estimator (OMCE) to estimate the future O&M costs of offshore wind farms, in: Proc. of European Offshore Wind 2009 Conference, Stockholm, Sweden. pp. 14¿16.

• Rausand, M., Høyland, A., 2004. System reliability theory: models, statistical methods, and applications. Wiley-Interscience, Hoboken, NJ.

• SIS Förlag AB, Maintenance terminology - Svensk Standard SS-EN 13306. Stockholm, Sweden: Swedish Standard Institute, 2001.