Coating considerations for Asset Protection RINA Conference London Marine Renewable & Offshore Wind Energy 21 st - 23rd April 2010 Alan Guy / Rodney Towers Safinah Limited
Jan 15, 2016
Coating considerations for
Asset Protection
RINA Conference London
Marine Renewable & Offshore Wind Energy
21st - 23rd April 2010
Alan Guy / Rodney Towers
Safinah Limited
Offshore Wind Energy UK
UK target 2020
15% of energy from renewables
Estimated that the UK has 33% wind resources in Europe
Offshore to be primary expansion zone. Wind is more constant and predictable
Jan 2010
UK govt awards Round 3 wind farm zones / 9 successful bidders
£75bn programme for offshore wind farm projectsSource: BWEA
UK Round 3 Wind farm zones
Offshore Wind Energy UKMW Capacity Plan
MW Capacity 2010 ( Feb ) 2015 2020
Operational 688
Under construction & planned
6,000
Zones awarded 33,000
Number of turbine towers ( est )
228 2,000 ± 11,000
Total Operational Capacity 10 year plan 40,000 MW
Largest Offshore Capacity Plan in Europe
This is a major growth business sector
Source RenewableUK
Offshore Wind Towers
Typical 3 MW Tower structure External m2
Internal m2
Totalm2
Painting area per tower 1250 1250 2500
Painting cost per tower
EP / PU multi layer @ € 5 / m2 € 6250 € 6250 € 12,500
Total cost Paint + Application
up to € 25 / m2 *
€ 31,250 € 31,250 € 60 – 70,000 per tower
* Source JPCL / Muhlberg March 2010
Painting Offshore Wind Towers
Offshore Wind TowersStructural protection in relation to project costs
Installation cost per MW € 3.3 mill
Installation cost per tower / 3MW € 10 mill
Painting cost ( P+A ) per tower € 60 – 70,000
Paint + Application as % tower installation cost
0.6 – 0.7%
Typical Wind Tower Structure
Factory painting + site erection painting ˂ less than 1% of installed cost
Offshore Wind TowersStructural protection in relation to project costs
Tower structures 2010 ( Feb ) 2015 2020
No. of Tower structures 228 2,000 11,000
Painting areas
2500 m2 per 100m tower 0.57 mill m2 5 mill m2 27.5 mill m2
Painting costs
Paint + Application€ 60 – 70,000 per tower
€14-16 mill €120-140 mill € 660-770 mill
If the build specification fails to performfailure repetition can multiply by the number of towers in the field
Overview Painting areas & costs
Offshore Wind Tower Fieldsoffshore repairs
Coatings unfortunately can fail
Offshore Wind Tower Fieldsoffshore repairs
Cost Problem
Access to offshore location
...not by road
....but
... by boat or barge
Offshore Wind Tower Fieldsoffshore repairs
Cost Problem Access to repair the coated surface
Staging difficult to erect & dismantle
Coating repairs
repeat
repeat
repeat
Offshore Wind Towers The coating repair cost multiplier
Operational cost problem
likely to be out of proportion
Offshore Wind Towersoffshore repair costs
Tower structures 2010 ( Feb ) 2015 2020
No. of Tower structures 228 2,000 11,000
Total Painting area
2500 m2 per 100m tower 0.57 mill m2 5 mill m2 27.5 mill m2
Total Painting cost
Paint + Application€ 60 – 70,000 per tower
€14-16 mill €120-140 mill € 660-770 mill
Assume 3% area failure 17,100 m2 150,000 m2 825,000 m2
Offshore repair cost up to €1000/ m2 € 17 mill € 150 mill € 825 mill
To repair only 3% area failure could cost more than the total initial cost of painting
Coating Breakdown
Coating performance failures can occur because of one or more of the following:– Design
– Product specification/selection
– Product quality
– Management processes
– Preparation/application
– Maintenance
– Repairs
– Climate/environmental control
– Worker skill
Product quality is rarely the cause of failure
Coating breakdownproblems for Asset Owner / Field Manager
Design, applicationSpecification ? System selection ? Application issues ?
Coating breakdownproblems for Asset Owner / Field Manager
Bad spray application
Sharp edges
Stress cracking in dry film
Photos ABS, Houston
Considerations for achieving long term coating performance
Purpose of coating systemAdopt the Functional Specification concept in design phase
Key point – performance 15 - 20 years or 35 - 40 years
Choose between multi layer 3 – 5 coat epoxy / p/urethane system
thermally sprayed Zn/Al + sealer/epoxy topcoats
‘green’ product 2–3 coat solvent free epoxy system
Asset Owner / Field Manager undertake independent technical evaluation of Paint Specification in Contract proposal prior to Contract agreement
Offshore Wind Towers three different environmental zones
Upper section - atmosphericblades, turbine, housings & structureCoating - durable, anti-corrosive
Lower section – splash / tidaltower structureCoating - durable, anti-corrosive
Bottom section– tidal/immersed/buried tower structureCoating - anti-corrosive, anti-fouling
Splash zone is the most critical
Offshore Wind Towers Coating selection
Structures similar to rigs, platforms and
ships
Difference unmanned
difficult to monitor/assess
Requirementslong term performance
suitable for fabrication process
suitable for range of environment
ease of repair
Needscare in selection
quality application
Offshore Wind Towers Coating selection
Principal methodology
ISO 12944-2
Defines corrosion category of site by rate of steel loss
Combine category with required durability to select generic coating schemes
– Non-immersed areas C5-M applies
– Immersed areas Im-2 applies
– ISO 20340 further defines requirements for high durability systems
Zone mm / yrSplash 0.4
Tidal 0.25
Immersed 0.2
Offshore Wind Towers Coating selection
schemes selected should have proven track records in the field
C5 Category Im-2 Category
3-6 coats EP + PU Total 300-500 microns
1-2 coats of solvent free EP Total 800 microns
3-5 coats Zinc silicate + EP + PU Total 300-400 microns
2-3 coats high solids EP Total 800 microns
1-2 coats solvent free EP Total 800 microns
2 coats glass flake EP Total 1000 microns
Coastal / offshore areas with high salinity
sea or brackish water
Generic 15 year maintenance free systems
Offshore Wind Towers Coating system for 30-40 years protection
Metallization has now achieved 30 – 40 years low maintenance protection on offshore oil & gas structuresThe cost and application speed for systems which include this process
are now close to or the same as for multi layer organic coating systems
The reasons are a combination of
New alloy materials
New technology spray equipment
Contractors improved ability to control the application environment
The current trend in Europe is to
thermally spray Zn / Al (first coat) 60 – 100 mic dft
+ sealer coat
+ 2 x EP topcoats
Full exterior surface and internally 6-8 m up from bottom
Painting Wind Towersthe importance of quality application
Best Quality Application requiresSpecified Standards of secondary surface preparation for steel & appropriate QC
Trained and skilful spray painting personnel
Applicators to conduct own DFT & QC work for multi layer coating systems
Applicators to have control over environmental conditions during the application process
The application contractor controls about 75-85% of the costThe importance of good application is fundamental for success
Painting Wind Towersfor long term coating performance
Photo Muehlhan Herning, Denmark
Optimum approach
Purpose built Wind Tower coating factory
Painting Wind Towersfor long term coating performance
Series of blasting & coating cells
Auto blasting / more consistent Rz and surface cleanliness
Some robot painting / internals
Two component spray equipment
Dust free environment
Climate & temperature regulation
Relative Humidity control
Photo Muehlhan GmbH
Painting Wind Towersfor long term coating performance
Spray application
epoxy / p/urethane multi layer
systems or topcoats
Photo Muehlhan GmbH
Painting Wind Towersfor long term coating performance
Thermal spraying
Zn / Al alloy
metallization PhotoMuehlhan GmbH
Painting Wind Towersfor long term coating performance
Finish painting internal areas
Photo Muehlhan GmbH
Wave & Tidal devicesPrototype design - testing – scaling up
Some differing environmental conditionsBut same considerations for long term coating performance
Offshore Marine Renewablesimpact of fouling
Wind Towerswill occur but impact on power generation and coating performance generally small
will be confined to tidal & immersed areas
Wave & Tidal devicesImpact could be significant. Issues may be
how to minimise fouling adhesion
differences between exposed surfaces
steel & composite materials
static or moving
possible impact of greater hydrodynamic loads on tethered devices from fouling build up
Offshore Marine Renewablestidal devices
In locations of ‘useful’ tidal range and flow, abrasion resistance of coatings and materials may be an issue
Coating Considerations for Asset Protection & Structural Integrity
Coating product quality failures are unusual. Specification failures are not
Three recommended actions for Client / Asset Owner / Field Manager
which can reduce risk
1. Apply the Functional Specification approach
Coating system suitability for performance requirement
Coating system suitability for the application process
Coating system suitability for the field environment
Coating system suitability for repair & maintenance
2. Make an independent technical evaluation of coating specification within
design phase and prior to Build Contract
3. Audit the coating process independently during construction phase
Post ISO 9000 wrong coating specification cases have doubled ! * * Source JPCL / K.Muhlberg Mar 2010
Unmanned structures
...deserve wise protection !
Sources & References
Sources of info & PhotosNaREC, Blyth, Northumberland
EMEC, Stromness, Orkney
Muehlhan GmbH, Hamburg
ABS, Houston
PapersK.Muhlberg / JPCL March 2010
‘ Corrosion Protection of Offshore Wind Turbines’
A. Momber / JPCL Apr 2008 & Apr 2009
‘ Investigating Corrosion Protection of Offshore Wind Towers Parts 1 & 2 ’
‘ Thank you ‘