FAQ: Addressing hyper load growth challenges with 7F upgrades

GE Vernova is observing widespread growth in gas turbine orders across regions such as SERC, MISO, ERCOT, and PJM, driven by demand growth, including increased electrification, and power needs from data centers to support artificial intelligence. These plants aren’t only being installed to meet capacity needs but are also being built to provide more flexible, dispatchable power to better complement renewable energy. To help enhance plant flexibility and aiming to allow thermal plants to effectively complement with increased renewable energy while maintaining grid reliability, Axial Fuel Staging (AFS) is available for 7F units. Customers are increasingly adding AFS because this technology improves turndown within emissions standards.

We recommend planning for your next outage 2-3 years in advance if you are considering an upgrade. Due to high demand, especially in North America, lead times for major upgrades like DLN 2.6+ and AGP Tech are now up. This increased demand reflects the growing adoption of these advanced technologies. To help ensure alignment with delivery schedules and to avoid bottlenecks, it is critical to plan early and engage with your GE Vernova account manager as soon as possible.

Variable Peak Fire and OpFlex Robust Extended Peak can be applied across all HGP and DLN hardware configurations. Super Peak, however, requires AGP or AGP Tech hardware to manage higher peak temperatures and associated loads safely. Keep in mind that any version of Peak Fire has maintenance factors that impact long-term part life (see GER-3620 for details) as well as potentially increased emissions that need to be considered. Contact your GE Vernova account manager for further details.

Yes, Axial Fuel Staging (AFS) is an option for DLN 2.6+ on simple and combined-cycle units. AFS enhances turndown flexibility, allowing plants to operate efficiently over a much more extensive load range while maintaining emissions compliance down to as low as ~25% gas turbine load. This feature is particularly beneficial in regions with a high penetration of renewable energy, where cycling duty has become more frequent.

OpFlex AutoTune protects the unit against high dynamics when using Robust Extended Peak on the DLN 2.6 or any peak fire operation on the DLN 2.6+. Combustion dynamics measurements are used as feedback signals to tune the physics-based models and actively adjust the fuel splits to mitigate risks of higher combustion dynamics during peak fire modes. While combustion dynamics may change slightly at elevated temperatures, the systems are engineered to manage these within acceptable thresholds. While there is a slight trade-off with higher NOx levels, the overall system stability and reliability are aimed to be maintained through these technologies.

Unflared units will experience a similar percentage improvement in output as flared units, but the absolute MW delta improvement will be smaller due to the lower baseload output of unflared units. While absolute gains vary based on initial configurations, operators can anticipate meaningful improvements regardless of flare status. Factors such as altitude and ambient conditions also influence the magnitude of these gains. The 7F roadmap below is for flared units only. Contact your GE Vernova account manager for unflared unit's output.

The baseline reference model is a flared 7F.03 equipped with DLN 2.6 and Enhanced Compressor Package 3 or higher. This model is used because it represents most of the fleet and serves as a consistent performance benchmark.

The higher the megawatt (MW) increase from an upgrade, the greater the exhaust energy and the potential impact on the Balance of Plant (BOP) systems, including the HRSGs. Inlet Airflow and filtration systems may also require evaluation to manage increased demands. Other systems that may require assessment include electrical systems such as the generator and generator step-up transformer. GE Vernova can conduct comprehensive BOP engineering studies on any site to assess the impact of one or more AGP upgrades and make recommendations to help ensure compatibility and maintain system integrity.

The maximum approved shaft limits for the 7F fleet are as follows: 

• 7F.03 is 197 MW.
• 7F.04 with Advanced Gas Path (AGP) hardware is 207 MW, while recent load coupling and hardware enhancements increase this to 214 MW.
• The 7F.04-200 configuration supports up to 225 MW. 
• The 7F.05 reaches up to 250 MW.

If a unit already has an Advanced Gas Path (AGP) with OpFlex AutoTune DX and Robust Extended Peak (REP), then only a software upgrade is needed to add Super Peak. You may need to assess if your BOP can accommodate the increased power at Super Peak firing temperatures.

No, a new HRSG is not generally required. A BOP impacts study is conducted to evaluate the capability of all BOP components to handle the increased output delivered by these upgrades. If the results of this study suggest that the full output increase would exceed the capability of existing equipment, then hardware upgrades to that specific limiting BOP equipment may be required, or the gas turbine output increase can be restricted to match the plant's capability if upgrading the BOP equipment is not economically viable.

While higher firing temperatures can reduce component lifespan, proper operations and maintenance practices can help ensure reliability. OpFlex AutoTune helps maintain combustion dynamic stability, balancing higher output with wear on combustion and Hot Gas Path components. Hardware upgrades enable increased baseload firing temperature and enhance performance without compromising reliability, thanks to better materials and technologies that improve repair and replacement intervals.

Peak firing options offer higher temperatures for improved performance but come with faster parts life consumption, as noted in GER-3620. Turbine owners have the flexibility to weigh increased output revenue against higher repair costs. An odometer can help track accelerated parts life in peak firing scenarios. In addition, the Capacity Trader product is an available option from GE Vernova’s Electrification Software business, which allows for “banking” hours during part-load operations, that can be used for peak firing without impacting maintenance scheduling, enabling maintenance-free peak firing.

There are several upgrade paths for the 7F.04 units including Advanced Gas Path (AGP) tech conversion with DLN 2.6+, followed by upgrading to the 7F.04-200 configuration and then to a full 7F.05 flange-to-flange (F2F) with optional Wet Compression. For existing 7F.04-200 units, the upgrade path includes adding Wet Compression before transitioning to a full 7F.05 flange-to-flange replacement. When planning these upgrades, operators should evaluate site-specific conditions and system requirements in a BOP study. This process might be completed differently depending on your needs. The best path for your plant is specific to your configuration, sector, and desired output increase. Contact your GE Vernova account manager to learn the next steps for your plant.