From Geothermal Waste to Gold: Indonesia’s Nanosilica Fertilizer Breakthrough

 From Geothermal Waste to Gold: Indonesia’s Nanosilica Fertilizer Breakthrough

In an era where sustainable agriculture and circular economies are no longer optional but essential, a remarkable innovation has emerged from Indonesia’s lush volcanic landscapes. Researchers at Gadjah Mada University (UGM), in collaboration with the country’s geothermal energy sector, have developed a groundbreaking process to transform silica waste from geothermal power plants into high-value nanosilica fertilizer. This innovation isn't just a scientific curiosity; it represents a tangible solution to several pressing global challenges, from food security and waste management to sustainable energy practices.

The Genesis of a Green Innovation

The story of this innovation begins not in a sterile laboratory, but in the geothermal fields of Indonesia, a country with some of the world’s most significant geothermal energy potential. For decades, geothermal energy has been lauded as a clean, renewable source of electricity, helping to power homes and industries while reducing reliance on fossil fuels. However, like all industrial processes, geothermal power generation produces byproducts.

One of the most abundant of these byproducts is silica, which precipitates from the geothermal fluids brought to the surface. For years, this silica was largely considered an unwanted waste, creating operational challenges and disposal costs. Researchers saw opportunity where others saw a problem. Professor Himawan Tri Bayu Murti Petrus, a faculty member at UGM's Faculty of Engineering, led a team that began processing this geothermal silica into nano-materials.

As Professor Himawan stated, "Geothermal silica has long been considered waste. We, on the other hand, view it as a strategic resource for sustainable agriculture".

The Science: How Geothermal Waste Becomes a Super-Fertilizer

The process developed by the UGM team is a masterclass in material engineering. Through careful processing and stringent quality control, they managed to convert raw silica deposits into stable, consistent nanosilica. The key lies in the word “nano,” as the silica particles are reduced to a size that makes them highly bioavailable to plants. The minute size of these particles allows for easy absorption, meaning plants can utilize the silica efficiently with minimal application.

The innovation doesn't stop at simple silica application. The researchers have created an integrated formulation that combines the nanosilica with humic substances and boron. This combination is crucial, as it doesn't just feed the plant but works to comprehensively improve overall soil health. This is a significant departure from conventional synthetic fertilizers, which often degrade soil quality over time.

The effectiveness of this innovation is backed by impressive field trial data. Across various commodities—from staple crops like rice and corn to high-value fruits like avocado, papaya, and grapes—crop productivity increased by a remarkable 30 to 50 percent. Perhaps even more astonishing is the efficiency of the product. The required dosage is exceptionally low, approximately 1-2 kilograms per hectare, a fraction of the amount needed for conventional macronutrient fertilizers like NPK.

A Story of Collaboration: From Lab to Field

This breakthrough is the result of a long and fruitful collaboration between academia and industry. The partnership between UGM and PT Pertamina Geothermal Energy (PGE) has been ongoing for years, predating PGE’s official formation as a company. This synergy is crucial, as it ensures that research doesn't remain confined to academic journals but is developed into practical, scalable solutions.

One of the key narratives of this collaboration centers on the Katrili booster. The innovation behind Katrili began somewhat serendipitously during the COVID-19 pandemic. A UGM geothermal expert, Dr. Pri Utami, visited PGE’s Geothermal Working Area and took samples for testing. "After analyzing the samples, I found they contained a wealth of materials. Silica was the main one, but there were also many other minerals. Its properties resembled volcanic ash. That’s when I thought, why not turn it into fertilizer?"

This initial thought sparked a major project. Dr. Utami and a nanotechnology expert from UGM, Dr. Ronny Martien, worked to transform the white silica powder into a plant-friendly booster. The formulation was further enhanced with chitosan, derived from shrimp and crab shell waste—another innovative use of waste material—which helps coat the plant surface, making it more resistant to pests and better at retaining water.

The collaboration extended to engaging local farmers. PGE provided training and support, understanding that this new type of booster required knowledge transfer for proper use. As Dr. Ngadisih, a soil and water conservation engineer from UGM, explained, "Katrili booster is new for most farmers because it works differently from the boosters, fertilizers, or pesticides they are used to. That’s why knowledge and skills transfer is crucial for proper and effective use. Like medicine, if used incorrectly, it won’t work as intended".

Beyond the Lab: Real-World Impact on Communities and Food Security

The true success of this innovation can be measured in its impact on the ground, particularly for farming communities. Farmers using the Katrili booster have reported significant improvements in crop quality and resilience.

For instance, farmers in Tonsewer Village, Minahasa, began using the booster on their tomato crops. The results were striking: "In terms of quality, the crops treated with Katrili booster were clearly superior to those using only chemical fertilizers. The fruits were larger and more resilient. Ripening was more consistent, with a much lower risk of rotting. The plants also withstand extreme weather better".

The positive feedback from farmers underscores a key advantage of this innovation: enhanced food security and farmer livelihoods. By improving yields, reducing vulnerability to pests and extreme weather, and offering a cost-effective alternative to chemical fertilizers, this technology supports the economic well-being of rural communities. Laboratory tests have also confirmed that crops treated with the geothermal nanosilica fertilizer are safe to consume, containing no heavy metals.

This success in Minahasa is not isolated. UGM and PT Geo Dipa Energi developed a similar liquid booster named "Sulasih-Sulanjana" for the Dieng Highlands in Central Java, after the gods and goddesses of fertility and plant protection in local Javanese mythology. The first potato harvest using this booster was conducted in July 2024, marking a key milestone in using this technology for horticultural crops in the region.

Geothermal Energy’s Multifaceted Role in a Sustainable Future

The development of this fertilizer is part of a broader trend of diversifying geothermal energy's benefits beyond just electricity generation. As Julfi Hadi, President Director of PGE, stated, "The use of Katrili Booster Fertiliser is concrete evidence that geothermal energy can contribute not only to energy self-sufficiency efforts, but also to strengthen national food security. This is an innovative step that is in line with our commitment to create added value from geothermal energy to support more sustainable and inclusive development in Indonesia".

This holistic view of energy is being embraced in other ways as well. PGE’s Geothermal Organic Fertilizer (GeO-Fert) initiative in the Kamojang area uses geothermal steam at 60–70°C to convert agricultural and household waste into solid and liquid organic fertilizer. This process, which won the ASEAN Renewable Energy Project Award, reduces drying time from two days to twelve hours, representing a 75% efficiency improvement and processing 57.6 tonnes of organic waste annually.

The Challenges and the Road Ahead

Despite its immense potential, challenges remain. The main hurdle for this technology lies in downstream processing and scaling up production. Moving from successful pilot projects and small-scale community use to industrial-scale, widespread adoption requires investment and infrastructure. Professor Himawan emphasized this, stating, "We want this innovation to truly enter the industrial value chain and provide tangible benefits". Expanding derivative product development is essential to ensuring the circular economy concept reaches its full potential.

The research is ongoing, with scientists exploring applications beyond agriculture, including the development of water vapor absorbent materials, biosensors, and biomaterials to support green technology.

A New Horizon for Sustainable Agriculture

The transformation of geothermal silica waste into nanosilica fertilizer is more than just an invention; it is a paradigm shift in how we think about waste and resources. It shows that with creativity, collaboration, and scientific rigor, we can address multiple challenges at once—reducing waste, boosting agricultural productivity, and strengthening food security.

This Indonesian innovation has the potential to be a game-changer for sustainable agriculture in the developing world. It offers a powerful, environmentally friendly alternative to chemical fertilizers and a solution to the pressing need for a circular economy in the energy and agriculture sectors. As the researchers at UGM continue to refine this technology and work towards wider implementation, it stands as a beacon of hope, proving that one nation's waste can truly become another's treasure.