With increasing connectivity across the country, and Jakarta’s position as the nation’s hub for business, finance, transport, education, technology and more, a serious blackout in the capital could potentially, bring down banking, IT, transport, and other critical services in Jakarta, and beyond.
Given this risk, constant modernization of equipment to minimize outages and boost plant performance, is a top priority for Indonesia’s electricity suppliers, including PT Pembangkitan Jawa-Bali (PT PJB) which owns, and operates, six power stations providing electricity in Jakarta, as well as East and West Java.
Enhancing Plant Performance and Energy Security
In Jakarta, PT PJB operates the 1600 MW Muara Karang (MK) combined-cycle power plant. Opened in 1979, and located in the northern suburbs, the MK plant is included in the 150 KV network which generates, and supplies electricity to some of Jakarta’s busiest business, retail, and government sector districts.
To reduce outage risk, while also boosting the performance and productivity of plant assets, the PT PJB management team initiated a major overhaul program last year, said, Rahmat Azwin, General Manager, PT PJB, Muara Karang.
“The upgrade focused on our block one 500 MW combined cycle plant that is powered by three GE gas turbines installed in 1992. Our overhaul objectives were improvements in plant readiness, reliability, and efficiencies, and reducing operating and maintenance costs,” said Azwin.
In early 2016, PT PJB appointed GE’s Power Services team to upgrade MK’s gas turbine combustion systems – where fuel combustion takes place – and the “hot gas path” components of the turbines (which are exposed to extreme heat). A state-of-the-art digital On Site Monitoring system was also installed.
Re-powering Muara Karang
A major part of the overhaul was the installation of GE’s 9E.03 gas turbine Advanced Gas Path (AGP) solution to existing turbines. AGP combines new components, with GE’s OpFlex analysis software which enables better control of turbines – in particular, the capability to adjust capacity more quickly when energy demand rises and falls.
“Performance-wise we have seen big improvements. During the day, our net capacity has increased to 106.8 MW from 90.5 MW previously. While at night, net capacity is now 110 MW – a 19.5 MW improvement from before,” said Azwin.
The AGP solution also maximizes turbine performance to reduce fuel consumption. In terms of heat rate - the amount of energy used by a power plant to generate one kilowatt of electricity - the MK heat rate (post upgrade) dropped from 10,985 BTU/kWh to 9,827 BTU/kWh – a 10.54% improvement.
Installing GE’s Advanced Extendor (AE) 32K hardware was the second part of the upgrade. The new AE parts, combined with AGP software reduce component wear, and combustion repair costs.
Commenting on this, Azwin said “The plant revitalization will make a big impact on the downtime needed to maintain our gas turbines in the future. Over a 12-year cycle, we expect to spend around 80 days on turbine maintenance compared to 198 previously. This includes 10 days for combustion inspection, 21 days for hot gas path checks, and 38 days for full inspections.”
Before and After
Azwin said the success of the Muara Karang overhaul has set the standard for PT PJB’s asset improvement programs in the future.
“The Muara Karang program demonstrates very well, how improved operational excellence produces a host of long-term benefits for the plant including further minimization of outage risk. In addition, our new capability to produce more energy from existing assets, is a great way to support the government’s goal of producing an additional 35,000 MW of power by 2019.”
Repowering MK was a milestone project for the GE Power Services team in Indonesia said Putu Ascita, Country Sales Leader, GE Power Services.
“Muara Karang is a stand out project for GE as it represents the first time that our Advanced Gas Path and Extendor 32K solutions have been installed by a customer in Indonesia.
“More important however, the upgrade exceeded the customer’s expectations. Post-overhaul tests, and trials, across key performance benchmarks show better than expected results and savings, and based on these, we hope to replicate this success with energy customers in other parts of Indonesia.”