Korean research team proposes optimal utilization strategy for hydrogen energy, the key to carbon neutrality

A joint research team, led by Dr. Sang Yong Park from the National Climate Technology Center at the Korea Institute of Energy Research (KIER) and Professor Dong Gu Choi from the Department of Industrial and Management Engineering at POSTECH, has developed an energy system model optimized for Korea's environment and proposed an optimal strategy for utilizing hydrogen energy.

Hydrogen is being highlighted as a key resource for achieving the government's "2050 Carbon Neutrality Scenario." It is not only a clean energy source in itself but can also be produced using surplus power from renewable energy and converted back into electricity when needed, making it highly suitable for managing variability and operating the power grid.

However, until now, there have been few studies that quantitatively and in-depth analyze the role of hydrogen energy at a national energy system level. Research that takes into account Korea’s specific energy environment is especially lacking, highlighting the need for a scientific approach to support national policy.

The research team successfully developed the KIER-TIMES model, which reflects Korea’s energy environment, based on TIMES (The Integrated MARKAL-EFOM System), an energy system analysis model by the International Energy Agency (IEA). Using this model, they predicted the optimal proportion of hydrogen energy needed to achieve national carbon neutrality by 2050.
^{* TIMES Model: A type of optimization model that identifies the cost-minimizing combination of energy technologies to meet the final energy demand of a country or region's energy system. It can analyze how changes in costs and efficiencies of various energy technologies impact the overall energy system costs and CO₂ emissions. As a result, it is widely used for assessing the economic and environmental impacts of energy and climate change policies.}

The KIER-TIMES model incorporates Korea’s current energy supply and demand, future energy needs, power supply plans, and energy prices. It specifically includes various assumptions, such as the final energy demand for 2050, as outlined in the government’s "2050 Carbon Neutrality Scenario Final Plan" (hereafter referred to as the "Scenario"), to ensure consistency with government policies. Additionally, sensitivity analysis was conducted to assess how changes in these assumptions affect the outcomes, thereby enhancing the model's reliability and applicability even when government policy conditions change.
^{*2050 Carbon Neutrality Scenario Final Plan (October 18, 2021, Carbon Neutrality and Green Growth Commission): This plan envisions the future state and sectoral transitions needed to achieve carbon neutrality by 2050, presenting two scenarios where the country's net carbon emissions reach zero. The scenarios are differentiated based on whether coal-fired power generation is completely phased out or partially maintained: Plan A (complete phase-out) and Plan B (partial retention).}

The findings from the model analysis indicated that in order to reach carbon neutrality at the national level by 2050, hydrogen energy needs to account for 27% of the overall energy supply. Furthermore, forecasts suggest that hydrogen energy's contribution to overall energy use is expected to rise to 25%.

In addition, the research team used the developed model to conduct an in-depth analysis of the proposed import share of hydrogen, improvements in water electrolysis technology efficiency, and the use of carbon capture technologies as outlined in the scenario.

The scenario sets the import share of hydrogen between 80% and 82%, considering the potential of domestic renewable energy. However, the research team's analysis indicates that at least 76% of hydrogen must be imported to achieve carbon neutrality, and a higher import share would increase the likelihood of achieving this goal.

The team also analyzed the reduction in power consumption achievable through improvements in water electrolysis technology efficiency. The national research and development target for water electrolysis efficiency is set at 94%. If this target is achieved, it is expected to reduce the country’s total power consumption by 6.4% and hydrogen consumption by 10.3%.

The research team also proposed a strategy for the use of carbon capture, utilization, and storage (CCUS) technology. Their analysis suggests that CCUS is more effective when applied to blue hydrogen* production facilities rather than being installed at natural gas power plants. Increasing the production of blue hydrogen can help reduce the reliance on green hydrogen**, which has higher production costs, making it a more cost-effective option.
^{* Blue Hydrogen: Hydrogen produced from fossil fuels such as natural gas, similar to gray hydrogen, but with a key difference: the carbon dioxide (CO₂) generated during the process is captured and stored rather than being released into the atmosphere, significantly reducing emissions.
** Green Hydrogen: Hydrogen produced by using electricity from renewable energy sources to split water through electrolysis, resulting in hydrogen production without any carbon dioxide emissions.}

Dr. Sang Yong Park Park, who led the joint research, stated, “This study is significant as it derives the role and optimal utilization strategy for hydrogen energy, taking into account Korea’s energy environment, using a methodology that aligns with international standards.” He further added, “We plan to expand the KIER-TIMES model to analyze the contributions of sector coupling technologies to carbon neutrality and to conduct research on their deployment and dissemination.”

Meanwhile, this research was conducted as part of the Sector Coupling & Integration (SCI) Convergence Research Group project, which was launched in July 2023 by the National Research Council of Science & Technology. The research findings were published on September 30th in Energy, a renowned international journal in the field of energy.