South Korea may need less than 30,000 t/yr of renewable or low-carbon hydrogen for the 500 GWh/yr of clean power generation that it seeks to subsidise in 2029-44 through a tender later this year, after Seoul sharply lowered its targeted volumes.
The government outlined its revised plans for a relaunch of a second clean hydrogen power generation bidding market tender on 8 June. It has shrunk the tender volumes to 500 GWh/yr from 3 TWh/yr after excluding ammonia co-firing as an option because of plans for an accelerated coal phase-out.
The amount of hydrogen required for the 500 GWh/yr will depend on the efficiency of the fuel cells or turbines used to generate the electricity.
Fuel cells typically have an efficiency of up to around 60pc and the most modern gas-fired plants — where hydrogen could be co-fired — can reach similar levels. At an average 60pc efficiency and based on hydrogen's lower heating value of 33.3 kWh/kg, around 25,000 t/yr of hydrogen would be needed to generate 500 GWh/yr.
In practice, achieved efficiencies could be lower. At an average of 50pc, roughly 30,000 t/yr would be needed to make 500 GWh/yr.
In any event, required supply is far below the 150,000-180,000 t/yr that would have been needed for the 3 TWh/yr considering hydrogen-based power generation only.
Hydrogen-equivalent volumes would have been even higher when assuming that much of the 3 TWh/yr would have been generated through ammonia co-firing with coal, given lower efficiencies. Around 1.45mn t/yr of ammonia, equivalent to roughly 250,000 t/yr of hydrogen, would have been needed for 3 TWh/yr of power when assuming an average efficiency of 40pc.
In a first round in 2024, all five bids submitted were based on use of imported ammonia.
Besides eliminating the ammonia option under the new design, the government is also shifting the focus for the hydrogen supply to domestic production as it wants to reduce dependence on imports.
The government notice states that the bid evaluation system will ensure that the process supports "the creation of a domestic clean hydrogen production ecosystem," indicating that selection criteria will be designed to favour domestic production over imports.
The carbon intensity of supply must again be below South Korea's clean hydrogen standard of 4kg of CO2 equivalent per kg of hydrogen.
Final rules will be set after a consultation with industry participants, the government said.
The government will also conduct a separate general hydrogen power generation tender for 950 GWh/yr of electricity output. This is open to any hydrogen without specific carbon intensity requirements and could involve use of supply made from fossil fuels without carbon abatement measures and of by-product hydrogen.
Based on the assumed efficiencies above, the 950 GWh/yr could require roughly 48,000-57,000 t/yr of hydrogen.
The government is planning more rounds going forward and will disclose volumes for these next year. This will take into account the 12th basic plan for energy supply and demand that is currently under development.
