KEPCO researcher proposes V2G for Korea's future grid flexibility
A Korea Electric Power Corporation (KEPCO) researcher, speaking on October 14, 2026, proposed that leveraging 1 million electric vehicles could provide approximately 10 GW of grid flexibility, addressing an anticipated 7.7 GW shortfall in long-duration flexible resources by 2035.
Our take
Is vehicle-to-grid (V2G) an investable flexibility resource in Korea yet?
Not yet: the fleet is large enough to matter, but Korean law defines only charging, not discharging to the grid, so there is no basis today to trade or settle V2G power; the business opens only when that rule and a settlement method are written.
In favour: the researcher's case is stronger than a capacity headline, because KEPCO's own trial found battery wear no worse than normal charging and most surveyed drivers said they would take part, which removes the two usual objections. Against: the barriers are rules, not technology, and there are several of them, from the missing discharge definition to possible double charging of VAT and the electricity industry fund and no type approval for bidirectional meters; and with most homes and cars in apartment complexes, who owns the charger and collects the revenue needs residents' agreement, with no overseas model to copy. On balance the rule changes decide it: the researcher cites Germany, where a commercial product followed three months after double grid fees on returned power were removed. All figures here are one researcher's estimates, not a government plan.
What the source says
- Domestic cumulative electric vehicle registrations exceeded 1 million units as of April 2026.
- Assuming 70-80 kWh battery capacity and 10 kW discharge output per EV, the total V2G capacity is 70-80 GWh, with an output of approximately 10 GW.
- Long-duration flexible resource supply is projected to shift from a 2.8 GW surplus in 2030 to a 9 GW shortfall by 2038.
- V2G capacity is estimated at 5-12.5 GW by 2035 and 8-20 GW by 2038, assuming a 10-25% continuous participation rate.
- The cost to secure 1 GW of flexibility is estimated at 934 billion to 2.8 trillion KRW for pumped hydro storage and 850 billion KRW for battery ESS.
- Current Korean laws define 'charging' but lack regulations for 'discharging' (reverse power flow), creating no basis for V2G transactions or settlement.
- V2G faces potential double taxation risks for VAT and electricity industry fund, along with a lack of type approval standards for bidirectional electricity meters.
- 60% of Korea's housing and 60% of its vehicles are concentrated in apartments, posing a unique challenge for V2G deployment compared to international single-family home or corporate models.
- Traditional battery diagnosis methods, requiring full charge/discharge, take 8-10 hours, cost 200-400 million KRW for equipment, and 2-3 million KRW per test, hindering the battery reuse market.
- Electrochemical Impedance Spectroscopy (EIS) can reduce battery diagnosis time to approximately 5 minutes by estimating State of Health (SoH) without full charge/discharge.
- Mandated 3-stage inspections for used batteries (pre-removal, post-remanufacturing, and periodic in-use) are expected to increase inspection volumes.
- The lack of public battery relay control protocols necessitates opening battery cases and directly connecting to cell modules for inspection.
- Integrating EIS into Battery Management System (BMS) AFE chips allows real-time internal cell temperature readings, improving accuracy for LFP batteries and extending thermal runaway warnings from 5 minutes to 2 hours (China's regulation).
- Wireless BMS can reduce costs by 5-6% compared to wired systems, ease maintenance, and facilitate used battery history management through integrated flash memory.
For investors — VPP operators / aggregators: there is no revenue route for EV discharge until the law defines it and a settlement method exists; track those two steps, then the apartment ownership question, before building a V2G offer.
Contracted storage investors: the 7.7 GW long-duration shortfall for 2035 is a researcher's estimate from the basic plan, not a procurement target; V2G is presented as a cheaper alternative, but without a settlement basis it does not compete for flexibility revenue today.
Watch: Legislative proposals or amendments defining 'discharge' in Korean electricity laws.
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