The total power exported by the plant in 2015 (Phases I and II) amounts to 1,293.9 GWh. The cumulative energy exported by the plant from initial commissioning is 21,216 GWh.
The aggregate average plant guaranteed net output (PGNO) for the reporting period was 91.8 MW for Phase I, and 204.3 MW for Phase II at an average ambient temperature of 29.87°C. The use factor (No. of fired hours as a percentage of the hours that the units were made available) was 15.0% for Phase I and 84.9% for Phase II.
Manah recorded 98.8% Reliability of the total Plant (phase I & phase II units) with 440.0 hours of Forced Outages in 2015.
Evolution of these figures from commercial operation date is as under:
|Year||Year Available energy
(*)COD Phase 1: 15th October 1996
(**) COD Phase 2: 19th May 2000
Maintenance and Operation methodology
The PPA and its additional agreements lay down norms for operation and maintenance of the station and expect certain minimum levels of performance. However, in formulating the strategy for operation and maintenance, UPC strives to meet the highest industry standards.
Gas turbines are highly reliable power generating machines, provided they are operated and maintained under certain norms. Efforts have been constantly put in to further improve reliability.
During the initial years of service of the gas turbines in Manah, valuable experience has been gained and used to establish unique signature for each machine. This experience is used in evolving better operations and maintenance methodologies.
For Phase I, UPC entered in November 1997 into a Spare Parts Supply & Repair Contract with EGT (now GE) the term of this contract ended on 31st December 2005. Following a competitive bidding process, UPC entered in September 2005 into a Long Term Parts and Repair Agreement (LTPRA) with GE the term of this new contract is 15 years.
For Phase II, UPC entered in December 2000 into a Long Term Service Agreement (LTSA) with GE. This agreement secures the procurement of the spares needed for the whole commercial life of the 2 new Frame 9 units (20 years).
In 2009, UPC changed the structure of its O&M Contracts and entered into an agreement with Suez-Tractebel Operation & Maintenance Oman (STOMO). With this agreement in place, UPC has a single point of contact for O&M services as opposed to multiple contractors in the earlier structure. STOMO now co-ordinates all the O&M activities (including the LTSA with GE) and procurement of parts through the LTPRA Contract.
According to the terms of these contracts, a suitable and sufficient stock of spares is maintained in order to avoid unplanned outage of the gas turbines.
The combined efforts of UPC and its contractors – GE and STOMO – have produced best results in terms of reliability, efficiency and best value for resources used.
Phase I Scheduled maintenance:
The total maintenance time consumed for the year was 1,071 hours, i.e. 4.08% of total calendar hours or an availability factor of 95.92%.
Annual maintenance carried out on all GTs.
Phase II Scheduled maintenance:
The total time consumed for maintenance was 907.6 hours in the reporting period, i.e. 5.18% of total calendar hours during reporting period or an availability factor of 94.82%.
Combustion Inspection undertaken on GT2A.
Performance tests were conducted during December 2015 for Phase I and II in the presence of OPWP. The test results were satisfactory, all machines have higher electrical output capacity and lower heat rate values (gas consumption) when compared to the guaranteed values as per contract.
UPC and its O&M contractor STOMO pay the greatest attention to respect the requirements of the Power Purchase Agreement in matters of Omanization: at the end of the year 2015, Omani employees comprised 80.85% of the plant staff of STOMO.
In order to address the Omanization issue, our operator, STOMO, had put in place in 2009, training programs for young graduates from Oman Universities. This effort is paying dividends with a number of these trainees being inducted into the operation & maintenance personnel of the Plant after undergoing training.