‘Cofiring’ Power Plants Hindered by Raw Materials Supply

KOMPAS/ISMAIL ZAKARIA

The coal feeder area of the Jeranjang Steam Power Plant (PLTU) in Taman Ayu Village, Gerung District, West Lombok Regency, West Nusa Tenggara, Monday (11/10/2021).

JAKARTA, KOMPAS — State electricity company PT Perusahaan Listrik Negara (PLN) started using the cofiring method at a number of coal-fired power plants (PLTUs) in 2020 to reduce the use of coal. This method uses 5-10 percent biomass with coal. However, it has been hindered by the problem of sustainable biomass supply in the field.

Indonesia has 52 cofiring PLTUs with a total installed capacity of 2,000 megawatts (MW). The biomass they use varies from rice husks, to wood pellets, and to oil palm shells. The biomass is supplies by the local community or entrepreneurs in the area of operation.

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Kompas' observation in the field last week revealed a problem in the lack of biomass supply at a number of cofiring power plants. This occurred at the 3x25 MW PLTU Jeranjang in Gerung district, West Lombok regency, West Nusa Tenggara. The coal supply for operating this PLTU reaches 500 tons per day.

PLTU Jeranjang senior supervisor of primary energy management Slamet Supriyanto said that cofiring using rice husks had stopped because of the biomass’s seasonal nature. In addition, the calorific value of rice husks was low at around 2,000 kilocalories per kilogram (kcal/kg), far below the calorific value of coal, which is around 4,000 kcal/kg.

"After running for a year, the supply of biomass continued to be limited, unable even to meet the needs of a 3 percent blend, which is equivalent to 15 tons per day per generator," said Slamet.

KOMPAS/ISMAIL ZAKARIA

Heavy equipment operator in the Coal Yard area of the Jeranjang Steam Power Plant (PLTU) in Taman Ayu Village, Gerung District, West Lombok Regency, West Nusa Tenggara, Monday (11/10/2021)

A similar issue occurred at the 2x7 MW PLTU Ropa in Ende regency, East Nusa Tenggara. This plant uses biomass in the form of pellets made from dried grass in a 5 percent biomass blend. The pellets contribute 15 tons of the 300-ton daily fuel supply that is needed, with the rest coming from coal. However, the two existing biopellet manufacturing machines are not sufficient to fulfill the daily demand of 15 tons of biomass.

According to the secretary of the Ende Environmental Office, Petrus Djata, the regency has an organic waste (biomass) potential totaling around 70 percent of the 110.86 tons of waste produced per day. The waste can be used as raw materials to produce biopellets. The key lies in procuring the biopellet manufacturing equipment.

Meanwhile, the 3x7 MW PLTU Sintang in Sintang regency, West Kalimantan, uses oil palm shells (OPS) blended with coal. Using the cofiring method, PLTU Sintang burns 13,500 tons of coal and 1,500 tons of OPS per month.

In Sintang, there are two suppliers capable of producing up to 5,000 tons of OPS per month, with each ton of OPS costing Rp 750,000. However, it is feared that the OPS are being sold to foreign markets, where they are priced higher.

It was necessary to convince the suppliers that PLN was the best buyer for their oil palm shells, but the problem was that PLN was not the sole market for OPS.

Ince Anjas, the manager of the Singkawang Generation Control and Implementation Unit (UPDK) that oversees PLTU Sintang, said that the OPS supply was sufficient for the power plant’s cofiring needs. It was necessary to convince the suppliers that PLN was the best buyer for their oil palm shells, but the problem was that PLN was not the sole market for OPS.

Agung Murdifi, PLN’s executive vice president for corporate communications and CSR, said the company was synergizing with other state-owned enterprises (SOEs) and suppliers. PLN was cooperating with the SOEs Perum Perhutani, PT Perkebunan Nusantara, and PT Sang Hyang Seri to ensure long-term biomass supply and availability.

KOMPAS/RADITYA HELABUMI

Muara Karang Gas and Steam Power Plant (PLTGU), Jakarta, Monday (7/6/2021).

In addition, PLN was also encouraging the potential establishment of a biomass industry by developing energy plantations and waste utilization. "To fulfill the biomass supply, PLN is coordinating with SOEs, local governments, and the private sector to ensure supply chain readiness," he said.

Meanwhile, according to Institute for Essential Services Reform (IESR) executive director Fabby Tumiwa, the availability of a reliable supply of wood pellets for cofiring power plants was a vital issue. Manufacturing wood pellets should also not lead to forest encroachment. The cofiring method could indeed reduce the consumption coal at PLTUs. (ZAK/FRN/ESA/APO)

(This article was translated by Hyginus Hardoyo)