The Turbine Supply Agreement (‘TSA’) is one of the most important contracts in any wind project. Despite being
predominantly a supply contract, there are several important elements which have an impact on the operational phase
of the project. As a wind farm owner (‘Owner’) with long-term exposure to the operational performance of the asset,
you need to ensure that the right level of detail is given to the “post take-over” sections of the contract.
Too often we see Owners and Operators with OEM service and maintenance agreements (‘SMA’)* that do not fully provision for alternative asset operational management strategies. In some respects, this is understandable considering that TSA, as well as the SMA, are normally signed many years before Owners have their focus on driving efficiencies in operational management. However, having the option to deploy an alternative operational strategy in
the future can be secured up-front by building in the right contractual clauses in the key supply agreements. This doesn’t just necessitate having commercially manageable “right to terminate” clauses in the SMA but also ensuring that technical and regulatory documentation required to bring in a 3rd party operator is contractually secured in the TSA.
*Some OEMs refer to SMA as SAA (Service Availability Agreement) or SWA (Service Warranty Agreement)
Some key focus areas which impact the operational phase that should be considered when negotiating the TSA are
summarised in figure 1 and explained in more details below.
Figure 1. Key focus areas within TSA impacting the operational phase
There is no standard way for defining Defect, Latent Defect or Serial Defect clauses in TSAs. When deploying new
technology as often the case in wind projects, the latter is of high importance. The TSA should place clear obligations
on the OEM regarding searching for Defects and the sharing of information from any technical RCA (Root-Cause
Analysis). In addition, a concise Defects liability section which clearly describes who bears the different cost elements
for Defect remediation is essential. This is especially pertinent for Owners seeking the flexibility to operate assets
themselves after an initial OEM Service Contract period.
Especially in offshore wind projects, the indirect cost of production loss during Defect remediation can be in the same
ball park as the direct costs associated with major retrofit campaigns (especially when main components / jack-up
vessels are not required). The Owner’s commercial position can be strengthened by concise contract wording which
leaves no room for interpretation regarding under which situations lost production is compensated for.
It is in the Owner’s interest to be able to measure the performance of the WTGs to ensure AEP (Annual Energy
Production) is in line with business case expectations. Whilst OEMs often provide warranted power curves, focus is
needed in the contract negotiation phase to ensure that the process for carrying out power-curve assessments is not
so cumbersome that any commercial claim becomes impossible.
Owners need to consider what their rights are in the event of OEM non-conformance during the warranty period.
Considering contractual disputes seldom end up in litigation cases, a carefully defined escalation process is necessary.
Having the potential to offset any outstanding TSA milestone payments against non-performed Defect remediation is
an extremely effective commercial tool for driving OEM performance and getting issues resolved quickly.
It is important to think-in the operational dimension to the design requirements of the turn-key TSA delivery. For wind
farms where turbine accessibility is costly and often restricted, reoccurring non-critical breakdowns or failures can
have a high impact on OPEX (OPerational EXpenditure) and lost production. Design requirements which describe
operational performance metrics for critical systems and components strengthen the Owner’s position when pursuing
Defect claims and lead to the implementation of correctly-engineered solutions that comply with industry best practice.
It is important that the documentation requirements of TSA contracts are fully elaborated. This is most effectively
done by a comprehensive list of documents that should be provided by the OEM at various milestones (for example,
before take-over or at the end of the Defects Notification Period). Owners need to think ahead: How can spare parts
be procured in year 15 of operation? Can spare parts be sourced more cheaply independently of the OEM? Has the
“as-is” documentation for the turbines been updated consistently throughout the period where the OEM is also
servicing the turbines? Are there obligations for handing over of documentation at the end of Defect Notification
Period (‘DNP’) or upon SMA contract expiry? For Owners who at some point wish to have the option to pursue
alternative operational strategies which don’t involve the OEMs, access to all the documentation required to service
and maintain the asset safely and in compliance with local regulation is critical.
Having full access to all aspects of the OEM SCADA system and park pilot, documentation which contains parameter
set-points and descriptions of the control philosophy is essential for Owners who wish to have the option to employ
3rd party service and maintenance contractors later in the operational lifetime. Turbine software and SCADA platforms
are evolving systems which are constantly updated, and Owners need to ensure that this is accounted for in the TSA
Owners often pay up-front for an extensive repertoire of spare parts from the OEMs based on OEM recommendations.
Consideration needs to be given to drafting of the contractual clauses to ensure that the Owner does not end up with
a stock of non-moving spare parts after several years of operation. Alternatively, one should ask the OEM why they
cannot hold the stock and provide a delivery guarantee.
There is a tendency for TSA and SMA contracts to become ever more intertwined with cross-references between the
two contracts. Owners need to ensure that any ambiguity cannot be used to the OEM’s advantage during the
operational phase. For example, if the Owner is responsible for the provision of HV switching or crew-transfer vessels
under the SMA/SAA, then who should bear the costs for these provisions for TSA Defect remediation work and at
what cost? More on SMA contracts in the next article upcoming in October.
Just reach out to us, we are always happy to get to answer your questions and get into discussions on optimized
operations and asset management!
Lars Conradsen | email@example.com | +45 23 25 50 70
Graham Henderson | firstname.lastname@example.org | +45 61 31 04 52