[Insight & Opinion] Expanding Biogas Can Accelerate RE100 Implementation

Organic Waste Such as Food Scraps
Technology Verification for Utilizing Natural Gas Infrastructure
Key to Achieving a Circular Economy

There is a Korean proverb that says, "You avoid poop because it's scary, not because it's dirty." It is a euphemistic expression meaning not to deal with wicked or trivial people. Human waste is no longer something to avoid but rather a resource to be utilized as energy. Food scraps, livestock manure, and human excreta are called organic waste. Imagine a village powered without nuclear or coal energy, but by biogas produced from livestock manure. Near the village, a generator runs without noise or foul odor. In Schl?ben, a town not far from Berlin, such energy self-sufficiency is realized.

On the 20th of last month, a discussion on expanding biogas took place under the chairmanship of the Prime Minister. The focus was on strategies to promote biogas production and utilization for eco-friendly treatment of organic waste and achieving carbon neutrality. Biogas, as Renewable Natural Gas (RNG), is an important strategic resource for addressing climate change, waste management, and other sustainability goals. Since the enforcement of the Biogas Act last December, stable implementation of biogas production targets, expanded support for integrated biogas facilities, and efficient use of produced biogas have been key objectives. The revision of the Urban Gas Business Act enforcement regulations allowing biogas producers to increase supply volume is also welcome. Considering the following points will greatly aid in activating biogas as a pillar of renewable energy.

First, biogas is a carbon-neutral energy source that can utilize existing natural gas infrastructure to reduce greenhouse gases and serve as an RE100 (Renewable Energy 100%) resource. It is a crucial area in waste management and utilization, enabling long-distance transport without reinforcing existing infrastructure such as pipelines. However, to maximize greenhouse gas reduction benefits or secure more RE100 energy from biogas, its energy efficiency must be improved.

Second, the amount of gas produced at each biogas production center is not large, resulting in many small gas engines with low power efficiency (35-40%), and seasonal production fluctuations cause significant waste. By aggregating dispersed biogas to operate large combined-cycle gas power plants, energy efficiency can be improved to about 62-65%, eliminating wasted biogas. This approach can draw ideas from renewable energy VPPs (Virtual Power Plants). Biogas produced in small, dispersed units is collected by RE100 member companies to increase volume. These companies then use city gas networks to generate electricity via large combined-cycle gas plants. The collected biogas and city gas used for power generation are calculated to settle the RE100 implementation scale. Although structurally simple, this method requires policy and institutional support. It is essential to support how much volume can be collected at reasonable costs. Cooperation among government ministries, local governments, and the private sector is necessary.

Third, utilizing large volumes of biogas in combined-cycle power plants can secure large-scale RE100 and complement the intermittency of solar and wind resources, providing stable energy supply for semiconductor manufacturing processes.

A circular economy centered on organic waste is a core strategy for achieving RE100. The Ministry of Environment will rapidly increase production through biogas activation policies. Technology verification for utilizing existing systems such as city gas pipelines has been completed. Now, institutional improvements are needed to collect dispersed biogas. This will enable early RE100 implementation, stable power supply, early market establishment of biogas, and reduction of public support costs. It is a triple-win opportunity.

Jowon Kyung, Professor at UNIST & Director of the Global Industry-Academia Cooperation Center