Wind Turbine Defects in Turkey: Manufacturer Liability, Warranty Claims and Lost Generation Damages – 2026 Updated Guide

Wind turbine defects in Turkey can cause major generation losses. Learn how foreign energy investors can pursue manufacturer liability, warranty claims, EPC contractor claims, repair costs and lost generation damages under the 2026 Turkish legal framework.

Wind turbine defects can create substantial financial exposure for foreign investors operating or acquiring wind power plants in Turkey. Blade damage, gearbox failures, generator defects, bearing problems, converter failures, transformer defects, control-system malfunctions and repeated turbine shutdowns may result not only in expensive repairs but also in months of lost electricity generation.

The financial significance of these disputes has increased alongside the expansion of Turkey’s wind energy market. According to the Ministry of Energy and Natural Resources, wind represented 12.1% of Turkey’s installed electricity capacity by the end of June 2026. Turkey had 413 wind power plants and total national installed electricity capacity had reached 126,113 MW.

For foreign wind energy investors, the central legal issue is usually whether the turbine manufacturer, EPC contractor, component supplier, operation and maintenance contractor, or another project participant is legally responsible for the defect. Establishing liability requires careful examination of contractual warranties, technical specifications, performance guarantees, defect notification requirements, limitation periods and the actual technical cause of the failure.

What Types of Wind Turbine Defects Can Create Legal Claims?

Wind turbines contain complex mechanical, electrical and electronic systems. A defect affecting a single critical component can substantially reduce turbine availability or result in complete shutdown.

Potential disputes may involve blades, blade bearings, gearboxes, main bearings, generators, converters, transformers, yaw systems, pitch systems, braking systems, towers, foundations, cables, control systems, sensors or SCADA infrastructure.

Blade defects may include cracking, delamination, bonding failures, erosion or structural weaknesses. Gearbox disputes may involve premature bearing or gear deterioration. Generator and converter problems can result in repeated shutdowns, while control-system defects may prevent a turbine from operating within the required parameters.

However, equipment failure does not automatically establish manufacturer liability. The technical cause must be identified before responsibility can be allocated.

Who Is Responsible for a Defective Wind Turbine?

Responsibility depends on the project’s contractual structure.

Some wind projects use a turbine supply agreement directly between the project company and turbine manufacturer. Others combine turbine supply with long-term service arrangements. In full-wrap EPC structures, the EPC contractor may assume responsibility for procurement, installation, testing and commissioning even where a turbine manufacturer supplied the underlying equipment.

Foreign investors should therefore review the complete contractual chain rather than focusing only on the turbine manufacturer’s warranty.

The turbine supply agreement, EPC contract, operation and maintenance agreement, long-term service agreement, component warranties, performance guarantees and warranty assignments should all be examined together.

A manufacturer may argue that the defect resulted from improper installation. The EPC contractor may argue that the component itself was defective. The maintenance contractor may argue that the problem existed before its services began. Technical root-cause analysis becomes essential in resolving these competing positions.

Manufacturer Liability for Wind Turbine Defects

A turbine manufacturer may be contractually responsible where equipment fails to comply with agreed specifications, warranties, quality standards or performance requirements.

Manufacturer warranties may cover defects in materials and workmanship, component failures, repair obligations, replacement obligations and specific technical performance requirements.

The precise warranty language is critical.

Investors should determine whether the manufacturer has merely agreed to repair defective equipment or has also assumed responsibility for transportation, crane costs, installation, dismantling, replacement components, labor and turbine downtime.

This distinction can materially affect recovery. Replacing a major turbine component may require specialist equipment and substantial mobilization expenses. A warranty that covers only the defective component may therefore leave the project owner with significant unrecovered costs.

EPC Contractor Liability

Where the EPC contractor assumed responsibility for turbine installation, balance-of-plant works, electrical systems, foundations, cabling, commissioning or overall plant performance, turbine problems may also create EPC claims.

An apparently defective turbine may actually be suffering from installation errors, foundation problems, electrical connection deficiencies or commissioning failures.

The EPC contract may contain warranties concerning workmanship, compliance with technical specifications, fitness for purpose, plant availability and overall performance.

Depending on the contractual allocation of responsibility, the project company may therefore pursue the EPC contractor even where the EPC contractor subsequently seeks recovery from the turbine manufacturer.

Warranty Claims Under Turkish Law

Turkey does not maintain a single statute exclusively governing wind turbine warranty disputes. Claims must therefore be examined under the applicable contract and the general framework of Turkish contract law, including the Turkish Code of Obligations where Turkish law governs the relationship.

Depending on the structure of the transaction, defective-work rules may become relevant where the contractor has undertaken to create and deliver a particular work. Sale-related warranty rules may also become relevant to equipment supply arrangements.

The applicable contractual classification should be determined carefully because it can affect available remedies, defect notification obligations and limitation periods.

Large wind energy contracts usually contain detailed negotiated warranty regimes. These contractual provisions should be examined together with any mandatory rules of Turkish law.

Defect Notification Can Determine Whether a Claim Survives

Foreign investors should act immediately when a turbine defect is discovered.

The relevant agreements may impose strict notification procedures requiring the project company to identify the defect, affected turbine, date of discovery and requested remedy within a specified period.

Informal telephone calls or technical discussions with the manufacturer should not automatically be assumed to satisfy contractual notice requirements.

A formal defect notice should generally identify the relevant turbine and component, explain the observed failure, refer to the applicable warranty provisions and reserve the project company’s rights regarding repair costs, replacement, downtime and generation losses.

Where the technical cause remains uncertain, the notice can reserve rights while an independent investigation continues.

Hidden and Systemic Defects

Some of the most valuable wind turbine claims involve defects that become apparent only after several years of operation.

A gearbox design weakness, blade manufacturing problem or bearing defect may initially appear in only one turbine. Similar failures may subsequently emerge across the entire turbine fleet.

Foreign investors should therefore investigate whether an individual failure is actually evidence of a systemic defect.

SCADA alarms, vibration monitoring data, oil analysis, maintenance records, inspection reports and failure histories across comparable turbines can be particularly important.

Where several turbines contain the same component or design, the investor should consider whether preventive inspection or replacement is required before additional failures occur.

Can the Investor Demand Repair or Replacement?

Potentially. The available remedy depends on the contract, warranty and applicable law.

A turbine manufacturer may reserve contractual discretion to repair or replace defective components. However, repeated repairs may become commercially unacceptable where the same problem continues to cause shutdowns.

The investor should determine whether the agreement contains escalation mechanisms for recurring defects, serial defects or fleet-wide defects.

Well-drafted wind turbine contracts may contain specific provisions dealing with serial defects. These can become extremely valuable where the same technical problem affects multiple turbines.

Can Wind Farm Owners Claim Lost Generation Damages?

Potentially, and lost generation can become one of the largest components of a turbine defect dispute.

A defective gearbox may keep a turbine offline for several months. Although replacing the gearbox may cost a substantial amount, electricity revenue lost during the shutdown can be even more significant.

Establishing lost generation requires a reliable counterfactual calculation showing how much electricity the turbine would probably have generated if the defect had not occurred.

This calculation should not simply multiply rated turbine capacity by the number of hours of downtime.

Wind conditions vary continuously. Technical analysis may therefore use wind measurements, turbine power curves, neighboring turbine output, SCADA information, historical production, availability data and other evidence to estimate expected generation.

Calculating Lost Electricity Revenue

After technical generation loss has been calculated, the financial value of that loss must be established.

Turkey’s Ministry of Energy confirms that electricity generated by licensed producers can be sold through the electricity market or bilateral agreements. Qualifying renewable facilities may also benefit from the applicable renewable energy support framework.

For 2026 specifically, EMRA determined the licensed facilities participating in the renewable support mechanism through its final 2026 renewable energy list adopted by the Energy Market Regulatory Board on December 30, 2025.

The appropriate revenue calculation may therefore depend on the project’s market sales, bilateral power purchase agreement, applicable support mechanism or other commercial structure.

Balancing consequences and additional replacement electricity costs may also require examination.

Grid Curtailment Must Be Separated From Turbine Defects

Lost generation caused by turbine defects must be distinguished from generation that would have been lost because of grid restrictions even if the turbine had been fully operational.

Suppose a defective turbine remained offline for ten days, but the wind farm was subject to grid curtailment during part of the same period. The project company cannot simply assume that all theoretical production during those ten days resulted from the turbine defect.

Similarly, unusually low wind conditions may reduce the amount recoverable.

A credible damages model should isolate the electricity that would actually have been generated and delivered but for the responsible party’s breach.

Availability Guarantees and Liquidated Damages

Wind turbine supply and long-term service agreements frequently contain availability guarantees.

Instead of requiring the owner to prove actual lost revenue for every period of downtime, the contract may establish minimum turbine or wind farm availability and provide predetermined liquidated damages where availability falls below the guaranteed threshold.

Investors should examine how availability is calculated.

Certain downtime may be excluded, including grid outages, force majeure events, owner-caused downtime or scheduled maintenance. Disputes often arise over whether particular shutdown periods should be included or excluded from the availability calculation.

The contract should also be reviewed to determine whether availability liquidated damages constitute the owner’s exclusive remedy or whether additional damages can be claimed.

Liability Caps and Lost Profit Exclusions

A strong technical claim does not necessarily mean that the investor can recover the entire economic loss.

Wind turbine contracts frequently contain liability caps and exclusions of indirect, consequential or lost-profit damages.

The contract may impose an overall liability cap and separate sub-limits for warranty claims, availability damages or performance damages.

Foreign investors should determine whether lost generation revenue is expressly recoverable, expressly excluded, or covered through an agreed liquidated damages mechanism.

The enforceability and interpretation of liability limitations must also be considered under the governing law.

Performance Bonds and Parent Company Guarantees

Recoverability is as important as liability.

A turbine manufacturer or EPC contractor may become financially distressed during a major defect dispute. Investors should therefore identify all available security before beginning lengthy proceedings.

Performance bonds, warranty guarantees, retention amounts, parent company guarantees and other security instruments may materially improve recovery prospects.

Expiry dates should be monitored carefully.

An investor may possess a valid multimillion-euro claim but lose significant leverage if the relevant guarantee expires while negotiations continue.

Insurance and Wind Turbine Defects

Insurance should also be reviewed immediately after a major turbine failure.

Operational all-risk, machinery breakdown and business interruption policies may potentially respond to certain physical damage and resulting revenue losses, depending on policy terms and exclusions.

However, insurance coverage and manufacturer liability are separate issues.

An insurer may pay a covered loss and subsequently pursue responsible parties through subrogation. The project owner should therefore coordinate warranty notices, insurance notifications and evidence preservation carefully.

Preserving Evidence Before Repairs

Major turbine repairs can destroy crucial evidence.

Before removing a failed gearbox, blade, bearing or generator, the investor should consider independent inspection and documentation.

Photographs, videos, serial numbers, SCADA data, vibration records, oil samples, maintenance records and damaged components should be preserved where appropriate.

The manufacturer or contractor may also need to be invited to participate in the inspection.

This is particularly important where the dispute may ultimately proceed to arbitration or litigation.

Wind Farm Acquisition Due Diligence

Foreign investors acquiring an operating wind farm should investigate turbine defect history before closing.

Turkey’s wind sector is substantial: as of the end of June 2026, wind represented 12.1% of national installed capacity, and 413 wind power plants were recorded in the country’s electricity generation portfolio.

Due diligence should examine turbine models, commissioning dates, manufacturer warranties, availability history, component replacements, gearbox and blade inspection reports, SCADA information, recurring alarms, outstanding warranty notices, long-term service agreements and unresolved manufacturer disputes.

The buyer should also determine whether existing claims remain with the project company or require assignment.

The share purchase agreement should include appropriate representations concerning known defects, warranty claims, serial defects, equipment condition and undisclosed downtime.

2026 Regulatory Context for Foreign Wind Energy Investors

Turkey’s licensed renewable electricity sector continues to operate under Electricity Market Law No. 6446 and the applicable licensing framework. Renewable generation projects generally require the relevant regulatory approvals, and licensed electricity may be sold in the electricity market or under bilateral arrangements.

Wind remained a major component of Turkey’s renewable capacity in 2026. This increasing investment scale makes equipment reliability, warranty enforceability and generation-loss allocation particularly significant for investors, lenders and purchasers of operational assets.

Equipment disputes remain principally contractual and technical matters, however. Changes in electricity market regulation do not automatically modify manufacturer warranties. Each claim must therefore be assessed under the contract applicable to the particular project.

Arbitration and Litigation Against Turbine Manufacturers

International wind turbine supply agreements frequently contain arbitration clauses, while other contracts may provide for proceedings before Turkish courts.

The governing law and dispute-resolution clause should be reviewed before formal action is taken.

Some contracts require negotiation, technical expert determination or other pre-arbitration procedures.

Because turbine disputes are technically complex, independent engineering experts frequently play a decisive role. Legal counsel and technical experts should coordinate from the beginning so that the liability theory and damages model rely on the same factual evidence.

Frequently Asked Questions

1. Can a foreign investor sue a wind turbine manufacturer for defective turbines in Turkey?

Potentially, yes. The investor’s rights depend on the turbine supply agreement, warranties, governing law, cause of the defect and dispute-resolution provisions.

2. Can lost electricity generation be claimed after a turbine failure?

Potentially. The claimant must establish liability, causation and recoverable damage. Technical evidence is normally required to calculate the electricity the turbine would have generated without the defect.

3. Who is responsible for a defective gearbox?

Responsibility depends on the root cause. A manufacturing or design defect may support a manufacturer claim, while improper installation, maintenance or operation may shift responsibility to another party.

4. What is a serial defect in a wind turbine fleet?

A serial defect generally refers to the same or substantially similar defect appearing across multiple turbines or components. Contract-specific definitions and remedies should always be checked.

5. Can an investor claim for repeated turbine downtime?

Potentially. Availability guarantees, liquidated damages provisions and general damages clauses may provide remedies depending on the agreement.

6. Can the manufacturer exclude lost generation damages?

The contract may contain exclusions or limitations concerning lost profits, consequential damages or generation losses. Their wording and enforceability under the governing law must be examined carefully.

7. Does replacing the defective component end the investor’s compensation claim?

Not necessarily. The investor may potentially have additional claims for recoverable downtime, repair-related expenses or generation losses depending on the contract and applicable law.

8. What evidence should be preserved after a major turbine failure?

Important evidence may include SCADA data, alarm histories, vibration records, maintenance reports, photographs, damaged components, wind measurements, inspection reports, correspondence and electricity generation records.

9. What should a foreign investor do immediately after discovering a major wind turbine defect?

The investor should preserve technical evidence, review warranty and notification deadlines, notify relevant contractual parties and insurers, obtain an independent root-cause assessment and quantify potential generation losses before substantial repairs alter critical evidence.

Legal Support for Wind Turbine Warranty and Generation Loss Claims in Turkey

Wind turbine defects can expose investors to substantial repair expenses, extended turbine downtime and significant lost electricity revenue. Successful recovery requires coordinated analysis of manufacturer warranties, EPC obligations, long-term service agreements, technical evidence, damages provisions and Turkish law.

Fırat Fesih Kaya Law Office provides legal assistance to foreign energy investors, international companies, wind farm owners, project developers and lenders in turbine manufacturer disputes, EPC contractor claims, warranty enforcement, serial defect claims, availability disputes, lost generation damages, renewable energy acquisitions, arbitration and litigation in Turkey.

If your wind farm is experiencing repeated turbine failures, gearbox or blade defects, abnormal downtime or generation losses attributable to defective equipment, you may contact our office for a project-specific legal assessment. Early involvement of experienced legal counsel and independent technical experts can help preserve warranty rights, secure evidence and improve the prospects of recovering compensable losses from responsible parties.

Phone: +90 312 434 22 22
Mobile Phone: +90 532 769 22 22
Email: info@firatfesihkaya.av.tr
Address: Mevlana Boulevard No: 221, Yildirim Tower No: 148, 06520 Balgat, Cankaya, Ankara, Turkey