High humidity, salt-laden sea air and persistently high fine-dust concentrations — under these harsh conditions, three GE FA.03 gas turbines experienced severe performance degradation. A targeted filter retrofit using EMW® (H)EPA gas turbine filters turned the situation around.
Performance losses were cut by more than half — delivering clear benefits in operational efficiency, lower operating costs, and tangible CO₂ reductions. Best of all: the retrofit was achieved without any structural modification to the existing filter house.
A detailed assessment of site conditions and operating data provided the foundation for this success.
The combined-cycle power plant (CCPP) is equipped with three GE 6FA.03 gas turbines, each rated at 77 MW, located directly in a tropical coastal port. Consequently, the turbines are exposed to extremely harsh environmental conditions:
| Category | Details |
|---|---|
| Tropical climate | Average temperature: approx. 25–28 °C |
| High humidity | Constantly around 80–89 % |
| Salt-laden sea air | Causes plant corrosion and high filter loading |
| Fine dust (PM₂.₅) | - On average approx. 10 µg/m³ above WHO limit - Air Quality Index around 53 = moderate load |
| Local emission sources | - Ship traffic and harbor industry - Local emissions lead to PM₂.₅ peaks |
The air filters originally in use were unable to cope with these extreme conditions. Frequent filter changes and poor particle retention severely affected turbine performance. After around 8,000 operating hours, individual units already suffered up to 1.30 % power loss — with a noticeable impact on plant efficiency and operating costs.
EMW® implemented an (H)EPA filter upgrade in Unit 3 – achieving a clearly measurable performance increase and lasting operational benefits. In the following case study, you’ll discover how a technical upgrade turned into a genuine success story.
Despite these environmental challenges, EMW® set a clear target: reduce operating costs and optimize turbine performance — without any structural changes to the existing filter house.
For several years, the turbines were operated with a filter configuration consisting of G4 pocket filters and F9 compact filters installed on separate filter stages. The G4 prefilters had to be replaced every few months due to limited service life, causing repeated operational interruptions.
Operating data analysis showed that the existing filtration system could not withstand the extreme site conditions. The most critical issue: compressor fouling reoccurred shortly after every turbine wash.
Key performance challenges:
| Challenge | Details |
|---|---|
| Declining compressor efficiency | ≈ –2 % within 6 months |
| Increasing fuel consumption | +65 Btu/kWh additional specific fuel use per year |
| Power loss per turbine | 2.5 MW per unit within 6 months → approx. 60,000 MWh annual total loss (3 turbines) |
Analysis showed that compressor fouling accounted for approx. 60 % of total performance loss — clearly linked to the inadequate performance of the previous filters. Pressure drop contributed about 9 % of the losses.
To address these weaknesses, EMW® developed an (H)EPA filter upgrade precisely tailored to the site’s demanding ambient conditions.
| 1st stage | 2nd stage | 3rd stage |
|
ISO ePM10 70 % |
ISO T8 |
ISO T11 |
Key features of the optimized configuration
The result: a customized filtration solution addressing the site’s climatic challenges — implemented without any modifications to the existing filter house.
The pilot turbine fitted with the EMW® (H)EPA upgrade showed a clear performance advantage within weeks compared to the two units still operating with the old filters.
Technical improvements
✔ Performance loss reduced by 60 %
✔ Stable compressor efficiency → equivalent to +2 MWh gain
✔ No compressor cleaning required for the first time in operating history
Filter life and differential pressure were significantly improved:
✔ GT pocket filters achieved 1 year service life (previous prefilters required earlier change).
✔ GT compact filters T8 also operated > 1 year without issue.
✔ GT (H)EPA compact filters T11 reached 3 years — triple the lifetime of the previous system.
Operational reliability increased notably: the new system handled peaks in humidity and dust load with ease — a decisive advantage under tropical conditions.
Pressure drop and economic balance
A common concern with (H)EPA systems is their higher initial pressure drop. However, field data clearly confirmed: the financial savings from reduced compressor fouling exceeded the additional cost of higher pressure drop by a factor of 14.
All three GE 6FA.03 have now been equipped with the EMW® (H)EPA upgrade — with outstanding results.
Economic benefits
✔ Total annual savings: ≈ USD 2,4 million (incl. filter replacement costs)
✔ High reproducibility: Results from the pilot plant can be reliably transferred to other sites
✔ CO₂ reduction: ≈ 3,500 tons per year = annual emissions of ≈ 1,500 average passenger cars
In summary, the EMW® gas turbine filter upgrade achieved multi-million-dollar savings while simultaneously enhancing operational reliability and extending filter service life.
The EMW® (H)EPA upgrade proves that even under extreme site conditions, efficiency can be safeguarded, costs reduced, and emissions lowered — without structural modification of the existing filter house.
Interested in boosting your gas turbine performance sustainably?
Contact us — EMW® provides tailor-made filtration solutions for your site.
