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Extreme weather events continue to expose the limits of modern power systems. Periods of severe cold or heat place simultaneous stress on electricity demand, fuel supply and generating equipment, turning routine operational weaknesses into grid-level risks.
Recent winter conditions in the United States offered a reminder that when demand surges and intermittent generation underperforms, grids fall back on power sources such as coal, gas, biomass, waste-to-energy and nuclear to maintain continuity of supply. In several regions, grid operators were forced to take emergency measures, including demand-reduction requests and temporary regulatory waivers, to keep generation online and avoid widespread outages.
These events are becoming more common and reflect a structural reality facing many power systems, that the grid increasingly depends on ageing thermal units, in some cases operating well beyond their original design expectations. As new capacity additions lag demand growth, reliability is determined less by capacity and more by whether existing assets can perform under stress.
When operating reality exceeds design parameters
During system stress events, dispatchable thermal units do more than supply capacity. They stabilise frequency, provide inertia and absorb rapid load changes at moments when the grid has minimal tolerance for deviation.
Many of these assets, however, were not designed for the operating profiles they now face. Increased cycling, longer run times and tighter operating margins have accelerated degradation mechanisms that reduce tolerance to transient stress.
As a result, grid emergencies are less often caused by major plant failures than by accumulated integrity losses across boilers, turbines and other systems that are revealed only when the system is under maximum strain and recovery options are limited.
Boiler tube failures causing unplanned power plant outages
During extreme weather events, boiler systems experience sustained high loads and rapid thermal transitions, increasing the likelihood that existing degradation will progress to failure at precisely the moment when the unit is most needed.
Boiler tube failures remain one of the leading causes of forced outages in thermal power plants, accounting for an estimated 60% of boiler-related shutdowns. Even small leaks require an emergency outage, resulting in production losses and secondary damage that affects other equipment components.
Boiler tubes operate under extreme thermal and pressure conditions that accelerate several degradation pathways. These typically fall into three categories:
- Water/steam-side mechanisms — corrosion, scaling and deposition that restrict heat transfer and create localised hotspots
- Fireside corrosion and erosion — accelerated metal loss from high-velocity flue gas, abrasive ash or corrosive species, especially in thermal, biomass and waste-to-energy units
- Thermal and mechanical stresses — creep, fatigue cracking and weld deterioration driven by prolonged overheating, cycling and vibration
Because early signs of tube deterioration are often subtle, faults can progress unnoticed until a leak forms. Proactive inspection — ultrasonic testing, temperature monitoring and condition-based assessment — is therefore essential to identifying at-risk sections before failure occurs. Advanced diagnostic approaches, such as PCA-based anomaly detection, have demonstrated that precursor signals can be detected hours before a trip, providing operators with a narrow but valuable window to intervene.
Why minor surface damage in gas turbines can lead to major outages
In large-frame gas turbines, relatively minor surface damage can escalate into efficiency loss, hot-spot formation and unplanned mid-cycle outages, often with limited early warning.
Surface damage in LF gas turbines, whether from spallation in the hot-gas path or oxide flaking in the compressor section, presents a significant yet sometimes under-recognised reliability risk. These issues typically develop in three ways:
High-temperature oxidation
- Loss of protective surfaces: oxide layers detach under thermal and mechanical stress, exposing base metal and accelerating deterioration
- Migration of debris downstream: flakes can plug cooling passages, erode vane surfaces and thermal-barrier coatings and contribute to hot-spot formation
- Late detection: because early-stage damage is difficult to identify, operators often discover the problem only after efficiency drops or hardware distress becomes visible, leading to unplanned mid-cycle outages
Strengthening critical components for longer, more reliable operation
Addressing these degradation mechanisms requires solutions that can be applied within existing outage windows, withstand aggressive environments and materially reduce failure risk without introducing new operational complexity.
As such, field-installed and OEM-validated protective claddings play an increasingly important role in maintaining the reliability of boilers, gas turbines and other high-temperature components in thermal power generation. HVTS is one such approach, applying a dense, corrosion-resistant and erosion-mitigating alloy layer that shields base metal from aggressive operating environments.
Flakes can plug cooling passages
In practice, the technology has been used to stabilise components experiencing accelerated wear, such as boiler tubes and turbine casings, by maintaining wall thickness and preventing localised thinning or pitting. The cladding’s durability supports longer run lengths and reduces reliance on reactive repairs, while its relatively short application time fits within planned outage windows without extending turnaround durations. These combined effects have allowed operators to reduce forced outages and manage lifecycle costs more effectively.
Case study: Restoring reliability at scale in the Philippines
The Philippines has one of the world’s highest concentrations of CFB boilers, many of which are ageing in parallel and exhibiting similar erosion and corrosion challenges. At one multi-unit site, boiler tube leaks were occurring once or twice per year despite previous mitigation efforts. These failures increasingly disrupted plant operations, undermined outage planning and created avoidable instability for the regional grid.
From reactive repairs to a predictable reliability strategy
HVTS application in the CFB boiler
As failures became more frequent and the financial impact of repairs and replacement power increased, the operator reassessed its protection strategy. The priority was no longer simply fixing leaks but reducing the likelihood of leaks occurring at all, within the constraints of normal outage windows and with a method robust enough for aggressive CFB conditions.
As part of this review, the plant engaged IGS to evaluate HVTS for the most affected boiler areas. The focus was on selecting a protection approach that could be executed consistently and repeatedly, while improving visibility into boiler condition and enabling clearer maintenance prioritisation.
The operator began with a single boiler, applying HVTS to the highest-risk areas identified during the outage. This first deployment provided structured insight into degradation patterns and created a clearer basis for deciding what to address immediately versus what could be deferred to future cycles. Following the success of the initial outage, the operator expanded HVTS across the remaining boilers and later formalised a long-term service arrangement, shifting from reactive interventions to a repeatable, long-term reliability programme.
Results and reliability improvements
Over multiple maintenance cycles, the site has achieved:
- Zero tube leaks in cladded areas
- No weld repairs and tube replacements in cladded areas
- Outages that run to plan
- A predictable generation profile for both grid and industrial customers
Their maintenance representative summarised:
“We used to plan for tube leaks, now we plan for uptime. Our outages run to schedule and we’re far more confident in the commitments we make to the grid and to our industrial customers.”
Case study video: www.youtube.com
CFB Boiler Reliability: How a Plant Stopped $300,000 Daily Losses
How improved asset integrity supports grid stability
During extreme weather events, grid stability depends not only on available generation capacity but on how consistently that capacity can be delivered. For operators managing ageing thermal assets, strengthening the integrity of boilers and gas turbines directly stabilises system performance. Improved asset condition supports grid resilience in several ways:
- Fewer forced outages reduce reserve-margin shocks and make dispatch more predictable
- Lower reliance on emergency shutdowns limits exposure to high-cost replacement power
- Consistent performance reduces the likelihood of politically sensitive load-shedding events
Together, these effects show how maintenance strategies that extend run lengths, slow degradation and reduce unplanned downtime contribute not just to plant-level reliability but to wider grid stability. As operators increasingly shift from reactive repairs to structured, long-term reliability programmes, the cumulative benefit becomes measurable at the system level.
Strategic recommendations for plant directors
1. Embed boiler and gas turbine integrity into reliability programmes
Plant directors should integrate tube condition, hot-gas-path health and degradation mechanisms such as oxidation, spallation and erosion into core reliability and root-cause analysis frameworks. Embedding these factors early enables clearer identification of high-risk circuits and more targeted intervention planning.
2. Extend run lengths and reduce O&M expenditure
Using protective technologies in suitable areas can slow corrosion and erosion, allowing longer intervals between major outages. Extending run lengths improves unit availability and helps moderate ongoing maintenance costs.
3. Optimise CAPEX through targeted protective measures
Directing protective cladding to areas with known wear risks can delay or avoid large-scale component replacements. This allows operators to shift part of their integrity strategy from capital expenditure to planned operational expenditure, reducing budget volatility.
4. Strengthen grid reliability and commercial performance
Lower forced-outage rates enhance dispatch compliance and improve key metrics such as AF, NCF and FOR. More predictable generation also improves competitiveness in power-supply tenders and long-term service agreements.
Extreme weather continues to test the limits of ageing thermal assets and grid resilience. For operators focused on reducing forced outages, extending run lengths and improving predictability under stress, proactive integrity strategies are becoming essential.
For more information, visit integratedglobal.com.
