Processing Waste, Harvesting Energy

This reportage is the result of the workshop "Building the Narrative of Energy Transition" organized by Clean, Affordable and Secure Energy (CASE) for Southeast Asia and supported by the Institute for Essential Service Reform (IESR) on 30 January-1 February 2023.
Photo & Text:
Aisyah Hilal & Dwi Oblo
Tuesday, 21 February 2023

The rain is still pouring down on Yogyakarta in the second week of February. At one point in the week it rained for several days without a break. But today, the weather has changed. The sun is already stinging when the clock strikes nine when I arrive at Gemah Ripah Fruit and Vegetable Market in Gamping.

Gemah Ripah Market is a fruit and vegetable trading place for people from Yogyakarta, Kebumen, Purworejo, Banjarnegara, Cilacap, Majenang and even Cirebon. This market has moved several times. Initially on Jalan Sriwedani-south of Beringharjo Market, then moved to the Pelem Gurih intersection, Jalan Wates. Then, the Sleman Regency Government moved it again to the location I visited, Jalan Wates, Ambarketawang, Gamping. Pasar Gemah Ripah stands on 1.5 hectares of land with six blocks containing 154 stalls.

This market is famous for its success in running a pilot project for biogas power plant installation, which was carried out collaboratively by Gadjah Mada University (UGM), Sleman Regency Government, and Gemah Ripah Market Cooperative. The Gamping Biogas Power Plant in this market uses raw materials from fruit waste coming from stalls in the market.

The roar of a garbage truck can be heard from the southwest corner of the market. Inside the truck, two men arrange piles of garbage. Some of their coworkers are outside the truck waiting for instructions to proceed before covering the truck’s load with a tarpaulin.

Ari and Samijan -- two of the ten market cleaners -- go from stall to stall, selecting and transporting fruit waste. The current crusher is only capable of chopping soft fruits, such as melons, watermelons, apples and dragon fruit.

“Right now the Piyungan landfill is quite congested. Truck drivers have to queue for two to three hours to dump waste there,” says Diono. Diono is one of ten market cleaners who are tasked with loading garbage from the stalls every day. “Under normal conditions, the queue only takes a maximum of 15 minutes,” he continued.

The Integrated Waste Disposal Site (TPST), more commonly known as the Piyungan Landfill, is the final processing location for waste from Yogyakarta, Bantul and Sleman. There have been several times when the Piyungan landfill was temporarily closed due to overcapacity or for infrastructure improvements. Usually, the closure lasts less than a week. However, the impact of the temporary closure was very significant. Garbage piled up everywhere, not only on the roadsides and in the markets, but also in the villages of Yogyakarta.

At a time when the queue for garbage disposal is congested like today, the existence of the Gamping Biogas Power Plant has solved two problems at once: independent waste management and a source of energy for communal enjoyment.

Ari -- the biogas installation operator -- checks the pressure of the gas flowing through the pipe from the biodigester to the pipe installation to the generator as fuel.

The Beginnings of Collaborative Working

Suharsini’s figure cannot be separated from the Gamping Biogas Power Plant pilot project. She is a fruit trader, a member of a cooperative, and was the Chairperson of the Gemah Ripah Market Cooperative in the 2003-2015 period.

“In 2003, the garbage problem in this market was quite troublesome. Half of the market was filled with garbage,” said Suharsini (60 years old).

As a graduate of the Plantation Cultivation study program at the Yogyakarta Institute of Agriculture, he knew that waste could be processed. Feeling his knowledge was limited, he actively sought training in waste management. “The first thing I understood was the natural technique of composting. That’s what I did. Of course, this composting technique causes odor. The villagers protested to us,” she said.

How can Suharsini not be overwhelmed? Market waste can reach four tons per day. At that time, the cooperation between Pasar Gemah Ripah and the Sleman Regency Environmental Agency (BLH) was to transport waste two days a week. Two hauls in one day. This means that in one week, BLH can only transport 16 tons of waste from Gemah Ripah Market to Piyungan landfill. In fact, in a week these piles of garbage can reach 24 tons.

“The difference of eight tons of waste is certainly a problem. The remaining eight tons continue to accumulate and accumulate. BLH then asked the market to complete the composting process. All new waste was taken to the landfill. This was done while waiting for the waste management facilities and infrastructure in the market to be ready,” Suharsini continued.

Suharsini, fruit trader, kiosk owner, member who once served as Chairman of Gemah Ripah Gamping Cooperative (2003-2015). During her tenure, she pioneered and developed a Biogas Power Plant with UGM, Sleman Regency Government, and funding support from Borås City, Sweden.

In 2007, Rahman Sudiyo and Siti Syamsiah, two lecturers at the Department of Chemical Engineering, Faculty of Engineering UGM managed to convince the University of Borås and the Municipality of Borås, Sweden, to finance a pilot project for biogas energy management from waste. To run this interstate project, Sleman Regency Government needs partners who have experience in managing waste. This is where Suharsini got involved.

“At that time, UGM conducted a series of surveys,” Suharsini said. “They examined the combination of two types of fruit, to test how much methane gas is needed. For example, a combination of watermelon with fruit A, pineapple with fruit B, grapes with fruit C. There were students who were responsible for making the chopping machine. Some make the separating machine.”

During this process, Haris Joni Rimbawan, an academic team member from Faculty of Engineering UGM, exchanged ideas with Suharsini. Haris and his two colleagues-Anggun Tati Rahmada Wardani and Fajar Marendra-are the successors of the project initiated by Rahman Sudiyo and Siti Syamsiah, who passed away in 2015 and 2016.

“We put 16 trucks of cow dung into two biodigester units. The cow dung serves as a starter, a source of energy for the microbes. Two-three weeks later, we can put in fruit waste,” Haris explains. In theory, four tons of waste can produce 330 Nm³ of gas and potentially 550 kWh of electricity per day. Biogas production below 50% can only be used for cooking or lighting a petromax lamp. “Between the 60th and 70th day, it is proven that biogas can do it,” Haris continued.

Fruit waste is fed into the crusher. A capacity of 180 kilograms of waste can be shredded in 20 minutes.
Coming out of the crusher, the fruit raw material with a pulp-like texture is collected in a tub. With the help of a suction machine, the fruit pulp is flowed upwards through a pipe, to further enter the biodigester.

The UGM team observed that the biodigester was able to produce a lot of gas. The production continues to increase until it reaches 70-80%. “Entering the third or fourth month, it even exceeded 110%,” said Haris. “From there we concluded that this biogas has the potential to be upgraded into electricity.”

In 2011, this abundant biogas production successfully became a source of energy to power the generator. “It felt so good to see the lights come on,” Suharsini recalls.

Electricity from the Gamping Biogas Power Plant has been able to power two 10-watt LED light points in all 154 stalls. Furthermore, it has also been able to power nine public street lighting points inside the market, each with 50-watt LED lights.

In addition to reducing the cost of electricity, the consistency of processing waste such as in Pasar Gemah Ripah is actually a concrete step to reduce greenhouse gases.

Ari shows the biodigester control tank. The water in the control tank serves to determine if there is a leak in the biodigester. In producing biogas, the biodigester must be fully anaerobic. Leaking biodigester will disrupt the gas formation process.

Playing with Microbes, Understanding Their Character

Working with fruit waste feedstock requires extra diligence. This is one of the challenges of biogas management to reduce our dependence on fossil energy. “The quality of fruit waste raw materials is difficult to maintain. It’s different from coal. Coal will have the same quality today or next month,” Fajar said. “Meanwhile, the quality of fruit waste cannot be fully controlled. There is a capacity that must be met to achieve certain stability,” continued the UGM academic.

Currently, almost all year round, the available fruit material is oranges. The amount can reach 80% of the total fruit traded. “The initial design of the biodigester is not strong with the limonene element of oranges. Limonene gas can affect the methane gas production power. So the biodigester needs to be adjusted again,” Fajar said. The safe threshold for the Gamping biodigester is to process two tons of waste. The acceptable limonene content can start from 10%. This means that 200 kg of orange waste and its peels can be included.

A pile of rotten oranges and dragon fruits in front of a stall inside the market. The market cleaning team that collects the leftover fruit for biogas has been trained to select the ones that are still suitable for use as raw materials. Citrus fruits currently dominate the types of leftover fruits that end up in the waste basket. The microbes in the biodigester need time and habituation to be able to process limonene.

“We are playing with microbes. They are living things. If we give them habituation, they will learn and get used too,” Fajar continued. “Based on research, even if it is only oranges as raw material, it still produces biogas too. The concentration of methane gas produced is smaller.” Actually, there are microbes that are still resistant to this condition. If added with other fruits, activators, and so on, when continuously trained, Fajar believes this process can still reach the expected standard.

From the beginning, the Gamping Biogas Power Plant was designed with the concept of independence in its management, care and maintenance. Although the basic concept adopts the technology used in Borås City. The design in Gamping is adapted to the climate and types of waste in Indonesia. Gamping Biogas Power Plant uses bacteria from cow dung as a starter. While in Borås, they have used genetic engineering so that the organic waste decomposes quickly.

“They [Sweden] expect us to adopt the technology and buy the starter from them too. However, Mrs. Siti insisted on using technology and bacteria from our own place so as not to depend on resources from Sweden,” Haris recalls.

The atmosphere of the workers' rest area at Gemah Ripah Gamping Market.

Fruitful Success

When the Gamping Biogas Power Plant started, one of the surveys conducted was in anticipation of the planned closure of the Piyungan landfill in 2012. As the Chairperson of the Gemah Ripah Cooperative, Suharsini targets that by that year the Gemah Ripah Market will no longer dispose of waste to the Piyungan landfill. “Even if there is any, it will only be the remnants,” she said.

At the same time, Suharsini decided to continue her education at the Master of Engineering Systems, Department of Mechanical Engineering, Faculty of Engineering, Universitas Gadjah Mada. The study she chose was Urban Waste Management Interest. She did this because she felt that she needed additional knowledge to overcome waste problems and to broaden her knowledge about renewable energy. In her eyes, waste is a resource.

Suharsini feels lucky that the problems she faced in the market developed into UGM’s field laboratory. She was also lucky to meet partners with a similar vision, Heru Saptono, an employee of Bappeda DIY, and Siti Syamsiah, an UGM academic. However, what they were doing did not go entirely smoothly. The Sleman regency government predicted the project would stall.

He, Heru and Siti were increasingly challenged to prove that the doubts were unwarranted. “I stayed at the market until 11 p.m. watching the workers lift the fruit waste so that in the morning we could process it two to three times. I hired 25 scavengers from Magelang and paid them to process the waste,” Suharsini recalls.

The biodigester requires 24 hours to complete the process of producing gas. The control stove in the generator room is one of the indicators to determine the gas production pressure.
Ari Hermawan, one of the members of Gemah Ripah Cooperative, is responsible for operating the Biogas Power Plant, from the beginning to the end.

Suharsini fully understands that waste and environmental matters require the cooperation of many parties. Gamping Biogas Power Plant is able to run until now because there are parties who have agreed to share roles and support. Gemah Ripah Cooperative manages the waste. Technology mastery is provided by UGM, from design to maintenance. The Swedish state supports funding for processing raw materials into gas, building construction, installation of biogas installations, and equipment. Meanwhile, Sleman Regency Government provides assistance to process gas into electricity, starting from the installation of electrical installations, purchase of generators, to lighting.

“Working in the environmental field, the challenge is not just cost. It also takes a strong will, strong commitment, persistent struggle, and secure funding for an initiative to really succeed and operate consistently,” Suharsini said. For her, the role of government is vital. Environmental initiatives cannot work alone. She is happy and will remain confident that the local government will give attention and support to other projects like this.

People often ask Suharsini whether the investment of billions is worth the results achieved by the Gamping Biogas Power Plant.

“Keep in mind, if the market is clean, market residents have good health, how much can be saved because the frequency of going to the doctor becomes zero? If the market is clean, officials come in, socialite moms in beautiful toe shoes are happy to come and shop, it will affect the turnover of traders. So, we have to think that way,” said Suharsini.

The atmosphere of one of the stalls at Pasar Gemah Ripah. The Gamping Biogas Power Plant is able to provide electricity to power two light points in each stall (@10 watts LED light). Also nine public street lighting points inside the market, @ 50 watt LED lights. The lights will turn on automatically if the PLN electricity is off.

The success of the Gamping Biogas Power Plant has attracted people to come and learn about biogas processing from raw waste. From the Department of Transmigration, PD Pasar Jaya Jakarta, the UN Environment Agency, to citizens of Timor Leste, Vietnam, and a German organization. And Suharsini feels a moral responsibility to keep the power plant going. “If it continues to be maintained, it is not impossible that electricity in the market can be turned on 24 hours using this biogas resource. There is no need to worry about rolling blackouts or sudden power outages due to bad weather,” Suharsini said.

At the end of our conversation, Suharsini’s eyes wander. “I learned a lot from the spirit of the late Mrs. Siti Syamsiah. She dreamed that this project could also be implemented in transmigration areas, areas that are still difficult to reach by PLN electricity. That way, energy independence has been prepared from the start,” Suharsini says with teary eyes.

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