The central government has designated the Special Region of Yogyakarta as one of the priority areas in the national Waste-to-Energy (WTE) project. The facility, targeted to begin operations in 2027, is seen as a swift measure to address the mounting waste problem. However, according to Professor Wiratni, a bioprocess engineering expert from Universitas Gadjah Mada (UGM), the project’s success largely depends on technical readiness and behavioral changes among waste-producing communities.
Professor Wiratni emphasized that the waste-to-energy plant (PLTSa) can only operate optimally if accompanied by proper waste segregation.
The facility should primarily receive dry waste to maintain thermal efficiency and prevent damage to equipment.
“If the waste remains mixed between organic and inorganic materials, the process will incur losses, and the investment could be wasted. A PLTSa can indeed be equipped with a drying system, but that would raise operational costs and cause unpleasant odors,” she explained on Thursday, Oct. 1, 2025.
Furthermore, Professor Wiratni noted that the PLTSa should not be the sole solution for waste management.
The root of the problem, she said, lies with humans as the waste producers.
“This project is indeed an idealistic one within the context of renewable energy. The philosophy behind it is excellent, but economically, it cannot compete with conventional electricity. Therefore, a more innovative electricity utilization strategy is needed,” the expert stated.
According to her, selling electricity to the state company PLN alone cannot ensure the project’s economic viability.
The economic feasibility of PLTSa projects must account for realistic tipping fees or the waste disposal costs at processing facilities.
She stressed that society must adopt a shared understanding that waste management is a service industry, not merely a public service.
With this mindset, waste producers will bear greater responsibility for reducing waste at its source.
Professor Wiratni added that while organic fractions can be used as feedstock for energy after drying, the perishable and odorous nature of organic waste makes large-scale transport inefficient.
“The challenge with organic waste is not whether it can become energy, but rather the logistics of transporting it from the source to the processing site. Economically, large-scale transport is required, but that could create problems similar to those at the Piyungan landfill,” she explained.
For organic waste, she recommended maintaining decentralized processing at the household or community level, located close to the waste source, through practical small-scale treatments such as composting or maggot cultivation.
She further noted that wet organic waste is not recommended for renewable energy feedstock, primarily due to transportation issues that can cause odor and potential disease along the route to the processing site.
Like other large-scale facilities, PLTSa plants also pose environmental risks, particularly through emissions from combustion and residual ash that contain hazardous compounds.
However, these risks can be mitigated with the proper use of technology.
“There are already clear guidelines to prevent negative impacts, such as referring to the Ministry of Environment’s regulations on permissible compound levels, installing appropriate equipment, and employing monitoring instruments,” she said.
As a practical step, Professor Wiratni suggested implementing incentive and disincentive mechanisms to encourage the public to sort and reduce waste.
The government, she added, should also map waste sources and existing off-taker ecosystems, such as waste banks and recycling businesses.
“Through such mapping, the PLTSa’s capacity can be focused solely on residual waste that cannot be processed further. The economic calculation should not rely solely on electricity sales to PLN but must also include a tipping fee mechanism as a disincentive. The PLTSa should not end up requiring more waste, since our goal should be zero waste through a circular economy ecosystem,” she concluded.
Author: Lintang Andwyna
Editor: Gusti Grehenson
Post-editor: Lintang Andwyna
Photograph: Kompas