Jakartans will have to suffer a series of black outs indefinitely after the state electricity company PT PLN announced that it is facing budget constraints to procure new transformers to help ease the capacity overload.

Nur Pamudji, PLN's general manager of the Java-Bali load control center and distribution, said Thursday that his office had planned a project worth Rp 5.6 trillion (US$583.3 million) to strengthen the city's electricity by 2012.

"The project was initiated in 2006, but we have made little progress due to funding constraints," he said during a workshop about the Cawang powerhouse in East Jakarta on Thursday.

He said the company could only spare Rp 800 billion from its budget, or 14 percent of the estimated cost, leaving a mammoth Rp 4.8 trillion deficit.

"We are still seeking other sources of funding, including from export loans, the state budget and the World Bank," Nur said, adding the company had just asked for permission from the government to look for Rp 3 trillion from export loans.

He said the projects included the procurement of eight power transformers, and the enhancement and looping of the 150-kilovolt capacity network.

The eight transformers, which cost Rp 200 billion each, would be installed to fortify existing transformers in some powerhouses, including Bekasi, Balaraja in Tangerang, Muara Tawar in Bekasi, Gandul in South Jakarta, Kembangan in West Jakarta and Cawang.

"The transformer procurement for Gandul is set to be complete by the end of 2010," Nur said.

He said the installment of two transformers for Balaraja was scheduled to be finished by mid-2011.

Only when the project is completed in 2012, will Jakarta be safe from any blackouts, he claimed.

Large swathes of Greater Jakarta suffered blackouts that lasted from Monday night until Tuesday evening because of lingering trouble at the Muara Karang and Gandul powerhouses.

The load in most city powerhouses was under pressure following the exploding transformer at the Cawang powerhouse on Sept. 29.

The Agency for Assessment and Application of Technology (BPPT), which is in charge of the investigation of the incident, announced the blast was triggered by dielectric losses and thermal instability in the transformer.

"The explosion was caused by the transformer's continuous and long exposure to high temperatures due to an overloading of the Cawang powerhouse, which reached over 90 percent of capacity," said Hamzah Hilal, a senior researcher in the agency.

He said Cawang powerhouse, which currently had two transformers, should acquire an additional two transformers to be used to share the load burden and for backup.

"The safe load burden is 60 percent of the transformer capacity."

Nur also said that black outs were inevitable with the limited number of transformers available to share the load.

City transformers had to shoulder up to 90 percent of its load capacity recently, higher than PLN's safety standard of 85 percent.

According to Nur, electricity demand in the city has risen by 5 percent annually.