Repowering a Damaged Combined-Cycle Power Plant with Four New Frame 5 Gas Turbines

PRIOS supports the recovery of an approximately 130 MW combined-cycle power plant in Ghana through owner’s engineering, OEM coordination and the facilitation of specialist work packages.

The project involves the removal of four damaged gas turbines, the planned reuse and reinstallation of the existing generators on new foundations, and the integration of four new GE Frame 5 gas turbines into the existing power plant infrastructure.

Recovering a Stranded Power-Generation Asset

A power plant does not necessarily lose its value because its prime movers have failed.

Where generators, steam-cycle equipment, electrical systems and other balance-of-plant assets remain technically recoverable, targeted repowering can offer a faster and more economical route back to generation than constructing an entirely new plant.

In this case, four gas turbines had suffered extensive damage, leaving the combined-cycle plant unavailable for an extended period. The central question was therefore not simply how to replace four machines, but how to integrate new gas turbines into an existing plant while retaining as much usable infrastructure as technically and commercially reasonable.

The resulting concept combines new Frame 5 gas turbines with selected existing plant assets, including the generators intended for reuse.

Repowering Is More Than an Equipment Purchase

Replacing gas turbines in an existing plant is a complex brownfield integration project.

New turbines introduce different dimensions, operating characteristics, dynamic loads, auxiliary requirements and mechanical interfaces. At the same time, existing equipment must be assessed against its actual condition after a prolonged shutdown.

The project also involves multiple parties with closely connected responsibilities:

• Gas turbine manufacturer
• Plant owner and project developer
• Dismantling and heavy-lifting contractors
• Civil and foundation specialists
• Mechanical and electrical installation contractors
• Generator and balance-of-plant specialists
• Logistics providers
• Commissioning and start-up teams

Without structured coordination, gaps between these individual work packages can quickly become schedule delays, technical disputes or costly variations.

PRIOS’ role is to create the connecting structure between the parties and ensure that technical information, responsibilities, decisions and deliverables are managed as part of one integrated repowering programme.

Owner’s Engineering and Project Governance

PRIOS was engaged to support the project through owner’s engineering and project-management services, beginning with the procurement, manufacturing and delivery phase of the four new gas turbines.

Our responsibilities include organising and supporting the coordination between the client, plant owner and turbine manufacturer. This involves regular OEM meetings, action tracking, schedule and deliverables monitoring, risk management, document control and the escalation of open technical or organisational issues.

A structured communication and responsibility matrix provides clarity over:

• Who is responsible for each technical input
• Which information must be supplied by the existing plant
• Which interface data are required by the turbine manufacturer
• Which decisions affect foundations, generators, auxiliaries and installation
• When deliverables are required to protect the overall schedule
• Which risks require early mitigation or management intervention

PRIOS does not replace the OEM, engineering contractors or specialist subcontractors. Our function is to make their individual scopes connect and to represent the project’s overall interests across the various interfaces.

Dismantling Four Damaged Gas Turbines

The existing damaged turbines must be removed without compromising equipment and systems intended to remain part of the repowered plant.

The dismantling concept therefore has to consider more than lifting and removing the turbine packages. It must define clear battery limits and address:

• Mechanical and electrical isolation
• Disconnection of fuel, lubrication, cooling and auxiliary systems
• Protection of adjacent equipment and structures
• Removal sequences and temporary access requirements
• Heavy-lifting and transport arrangements
• Identification and preservation of reusable components
• Documentation of the condition after removal
• Handover of cleared areas for subsequent civil works

PRIOS supports the definition and coordination of these requirements so that the dismantling package is aligned with the future installation concept rather than treated as a separate demolition activity.

Reusing the Existing Generators

The planned reuse of the four existing generators is a central element of the repowering strategy.

Generator reuse can preserve substantial asset value and reduce both capital expenditure and delivery time. It must, however, be supported by appropriate condition assessment and detailed interface verification.

Relevant considerations include the condition of the stator, rotor, bearings, cooling systems, excitation equipment and protection systems. The shaft train, coupling arrangement, alignment tolerances and electrical compatibility must also be assessed against the requirements of the new gas turbines.

The generators cannot simply be declared reusable because they already exist. Their technical condition and their compatibility with the new turbine configuration must be demonstrated before they are incorporated into the final installation concept.

New Foundations for the Repowered Units

The new Frame 5 turbines cannot automatically be installed on the foundations of the original machines.

Differences in equipment footprint, mass distribution, dynamic behaviour, shaft height and operational loads require a dedicated civil and structural solution. At the same time, the new foundations must accommodate the planned reinstallation and precise alignment of the existing generators.

This creates a critical interface between:

• The new gas turbines
• Existing generators
• Baseframes and coupling arrangements
• Foundation design
• Existing underground services
• Turbine-hall access and lifting provisions
• Inlet, exhaust and auxiliary systems

PRIOS facilitates the exchange of information between the relevant specialists and helps ensure that equipment data, civil requirements and installation planning develop together.

Integrating Four New GE Frame 5 Gas Turbines

The four new Frame 5 gas turbines form the core of the repowering programme.

During the manufacturing and delivery phase, PRIOS supports the client through structured OEM coordination, milestone tracking and review of the information required for site integration.

The focus is not limited to the turbines themselves. Successful integration also depends on the timely coordination of:

• Fuel-gas interfaces
• Lubrication and cooling systems
• Air-intake and exhaust arrangements
• Control and instrumentation systems
• Electrical and generator interfaces
• Existing heat-recovery equipment
• Fire and gas protection
• Installation and commissioning requirements
• Transport, lifting and site-readiness planning

Each turbine package must ultimately operate as part of the existing combined-cycle plant. The surrounding systems therefore have to be considered from the beginning of the replacement project.

Facilitating the Specialist Work Packages

Projects of this nature rarely fail because no capable contractor can be found. They fail when capable contractors work against incomplete scopes, conflicting assumptions or unclear interface responsibilities.

PRIOS helps the project owner and developer structure the required packages, identify dependencies and establish a consistent sequence from dismantling through to installation and commissioning.

This includes supporting the coordination of specialist companies for:

• Existing-plant condition assessment
• Gas turbine dismantling
• Generator inspection and rehabilitation
• Civil and foundation works
• Mechanical and electrical installation
• Heavy transport and lifting
• Balance-of-plant modifications
• Controls integration
• Testing and commissioning

The objective is not to place every activity under one oversized contract. It is to create clearly defined scopes that can be procured and executed individually while remaining part of one controlled project structure.

Turning Plant Failure into a Controlled Recovery Programme

The project has progressed from an equipment-replacement concept into a structured multi-package repowering programme.

PRIOS has established the coordination framework for the manufacturing and delivery phase of the four new turbines while supporting the preparation and alignment of the work packages required at site.

The project demonstrates how a damaged power plant can be approached as a recoverable industrial asset. By combining new rotating equipment with technically suitable existing infrastructure, owners can potentially restore generation capacity faster and with lower capital requirements than through a complete greenfield replacement.

The decisive factor is disciplined interface management. Every retained asset, new equipment package and contractor scope must fit into one technically coherent and commercially controlled execution plan.

Fast-Track Power Plant Repowering

Demand for new generation equipment is increasing while OEM manufacturing capacities and delivery schedules remain under pressure.

Repowering existing plants can provide an alternative route to additional generation capacity. It allows usable infrastructure, grid connections, utilities and selected plant equipment to remain in service while the critical technology is replaced or upgraded.

Such projects require an experienced owner’s engineering team that understands both the existing asset and the requirements of modern equipment suppliers.

PRIOS combines technical project experience, OEM coordination and international contractor management to support power plant owners and developers from the initial recovery concept through manufacturing, construction and commissioning.