Prisoners at Pangkalpinang Prison Produce Compost from Coal Waste
Inmates at the Tua Tunu Class II A Prison in Pangkalpinang have successfully produced and sold compost fertiliser made from waste generated by burning coal at the steam power plant (PLTU), known as Fly Ash Bottom Ash (FABA).
The head of the Tua Tunu Prison in Pangkalpinang, Sugeng Indrawan, stated that the compost production capacity is carried out by eligible inmates under strict assimilation conditions, yielding 6 tonnes every two weeks.
“Production capacity is still small because it is done manually. Every two weeks, we produce 6 tonnes of compost. However, we have already received support from the Governor and local government for the development of this compost,” said Sugeng after the launching event for the shipment of compost produced by the Pangkalpinang Class II A Prison, under the guidance of PT PLN Nusantara Power Services PLTU 3 Bangka, on Thursday, 26 March 2026.
Sugeng explained that the raw materials for the FABA waste compost from the Bangka PLTU receive full support from PLN and are accepted by them without any payment. Abundant raw material stocks, he said, serve as capital to increase production capacity.
“We do not want the current product output to be limited to just a few tonnes. We want improvements in both quantity and quality. That is what we hope for in the future, so we need collaboration and synergy with various parties,” he stated.
According to Sugeng, the prison also provides agricultural extension services or Demonstration Plots (Demplot) to farmers in the field before using the prison’s compost product. From those trials, he said, farmers’ harvests have been significantly improved.
“We trialled it on palm oil plantations and the results were good. We are even struggling to meet farmers’ demands. The latest request from farmers in Kotawaringin was for six tonnes, which has not yet been fulfilled as we are still waiting. Our plan is to use it for durian and avocado orchards,” he added.
The Manager of the Bangka PLTU Unit at PT PLN Nusantara Power Services, I Gusti Ngurah Putra Astawa, stated that the Bangka PLTU currently produces 65 tonnes of FABA waste per day, with current stocks amounting to 39,000 tonnes. This waste, he said, must be disposed of within three years in accordance with the Minister of Environment Regulation.
“The PLTU waste that we are collaborating on with Pangkalpinang Prison is for processing and mixing into fertiliser for compost production. We all know that the soil in Bangka has low acidity levels or pH. So, the FABA turned into compost can neutralise the soil before it is used for plantation land,” said Astawa.
In addition to being a compost mixture, Putra noted that FABA waste is also utilised as a mixing material for making bricks as a cement substitute, backfill soil, and materials for creating artificial coral reefs or fish aggregating devices for waters around Bangka Island.
“Our hope is to realise a sustainable circular economy. However, this innovation certainly requires collaboration. We hope to continue providing creative ideas to produce new products from the raw materials we have. Our slogan is free; PLN never charges a penny for the utilisation and absorption of this FABA,” said Astawa.
The Governor of Bangka Belitung, Hidayat Arsani, added that the provincial government is supporting the development and increased production of compost from Pangkalpinang Prison by providing processing machines, clean water through borehole construction, and two water tanker units.
“We hope that the inmates at Pangkalpinang Prison can contribute to society after their release. With this economic empowerment, the inmates here can also generate their own income. We will fully support this effort to ensure its future success. Especially since I hear the results are very satisfactory. Of course, we must support it,” he said.