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Gapa Island

Current status, energy mix, organizations, suppliers, equipment, controls, reported specifications, and project updates—with source-level citations.

CoverageDetailed public record
Named organizations7
System facts17
Sources reviewed12
Evidence reviewed2026-07-20

Gapa Island is Gapado (가파도), Jeju's early Carbon Free Island demonstration. The original 2011-2016 system combined 500 kW of wind, roughly 141-174 kW of rooftop PV, three 150 kW diesel generators, and staged battery/PCS installations reported between 2 and 3.864 MWh. It demonstrated multi-day renewable-only operation, but Korean government and National Assembly material now describes the original project as unsuccessful because of maintenance, parts-supply, and owner/operator coordination failures. A new Gapado RE100 project is being designed to replace it with grid-forming controls, much larger storage, and new renewables.

Research status
Original system no longer functioning as intended. In 2025-2026, Korean government sources acknowledged that the first Carbon Free Island effort had failed or stopped operating properly and that Gapado was again supplied primarily by 1.2 MW of diesel generation plus household solar. A replacement project was still in design in March 2026, with renewable supplier selection anticipated as early as November 2026 and completion targeted for 2027. The latest report gives a revised 2026 budget of KRW 8 billion and total cost of about KRW 14 billion, which differs from the National Assembly's earlier KRW 22 billion one-year budget-plan description.
Historical classification
Island
Reported capacity
See component specifications
Coordinates
33.17002, 126.27152
Evidence note: “Every company” cannot be proven from public material alone. This page lists every organization found in the recovered record and reviewed sources, preserves unknown roles, and explicitly marks undisclosed controller or equipment details.
Report missing evidenceResearch methodology

Project delivery

Who was involved in Gapa Island?

7 publicly identified organizations. Where a recovered source named a participant without explaining its work, the role remains explicitly unspecified.

Organization

Hyosung Heavy Industries

Supplier/integrator associated with the original project's ESS, power-conversion, and microgrid systems. Its published 1 MW/2.3 MWh and 3.25 MW/3 MWh references describe vendor scope or different stages, not one reconciled total asset rating. [7][8][2]

Organization

Jeju Government

Publicly named participant; role not specified in the recovered record [1]

Organization

Jeju Special Self-Governing Province

Provincial sponsor of the original Carbon Free Island program and government partner in the replacement Gapado RE100 effort. [3][10][12]

Organization

KEPCO

Publicly named participant; role not specified in the recovered record [1]

Organization

Korea Electric Power Corporation

Led and operated the original Carbon Free Island microgrid and its control center; designated recipient/operator for core wind and storage components of the new RE100 project. [3][10][11][12]

Organization

Korea Energy Agency

Assigned the household-efficiency and distributed-energy portion of the replacement plan, including solar and heat pumps for 83 homes in the National Assembly's budget review. [11]

Organization

Korea South-East Power Co. (KOEN/KOSPO)

Owner/operator identified for the two original Siva 250 kW wind turbines. [9]

System evidence

Energy mix, capacity, and specifications

Values can describe different project phases, generation sources, storage systems, or other components. Source citations are attached to each figure so discrepancies remain visible.

Original wind generation
Two 250 kW Siva induction-generator turbines, 500 kW total, commissioned in September 2012 [9][5][6]
Original rooftop solar capacity
Sources report approximately 141-142 kW for 47-48 three-kW systems, 144 kW in another table in the same field paper, and 174 kW across 48-50 households in public project accounts. These are preserved as scope/date differences rather than forced into one value. [5][4][6][3]
Original diesel generation
Three 150 kW generator sets, 450 kW total, with research accounts commonly describing two operating and one reserve [5][4][6]
Original battery and PCS configuration
Final-stage field account: 3 MWh plus 864 kWh of batteries, served by three 1 MW PCS units plus one 250 kW PCS. Other studies simplify the system to 1 MVA/2 MWh or 3 MWh, while a 2020 review identifies 3.0 MWh lithium-ion plus about 0.85 MWh lead-acid. These appear to reflect stages and study boundaries. [5][4][6][7][8]
Original demand
Research sources report average demand around 119-120 kW and maximum demand around 230-300 kW [5][4][3]
Replacement wind and storage plan
National Assembly budget review: 2.3-4.2 MW wind and 20 MWh ESS, plus 249 kW household solar. March 2026 reporting confirms a grid-forming, storage-heavy design but does not yet establish awarded or as-built ratings. [11][12]
Current island demand and diesel supply
March 2026 report: average demand 227 kW, 2025 electricity use 1.99 GWh, and 1.2 MW of diesel generation providing the primary supply alongside household solar [12]

Controls and hardware

Equipment and controller details

Manufacturer and model are shown only when a source names them. Generic descriptions are not converted into guessed product assignments.

01

Original wind turbines

Siva

Two 250 kW induction-generator turbines commissioned in September 2012; the official wind inventory does not provide a model number. [9][4]

02

Original energy storage and power conversion

Hyosung Heavy Industries

Hyosung identifies Gapado as an ESS/microgrid reference and describes its role in microgrid development. Field literature reports multiple PCS and battery blocks added through 2016; public sources reviewed do not fully reconcile vendor, chemistry, or capacity by block. [7][8][2][5]

03

Original diesel generators

Model not publicly disclosed

Three 150 kW sets provided backup and restoration when battery state of charge was low. Manufacturer and model were not disclosed. [5][4]

04

Replacement grid-forming system

Model not publicly disclosed

The replacement is explicitly planned around grid-forming technology, a large ESS, wind, household PV, and heat pumps. Procurement was not complete by March 2026, so no manufacturer, model, or final rating is assigned. [11][12]

Technical record

Architecture, performance, and project updates

Concise technical facts, milestones, operating results, and later developments. Dated notes distinguish historical design claims from current evidence.

  • Original islanding architecture

    Battery PCS operated in constant-voltage/constant-frequency mode to form the island grid. Diesel generation reconnected at low state of charge, while wind output could be curtailed at high state of charge; the staged PCS blocks supported both grid formation and renewable smoothing. [5][4]

  • Demonstrated renewable operation

    A 2020 technical review reported periods of up to seven consecutive days supplied only by renewables and storage by 2018. This was a best operating interval, not proof of year-round diesel-free service. [6]

  • Power-quality constraint

    Research found that the two concentrated squirrel-cage induction wind turbines could create high inrush and voltage flicker when connected, placing unusual demands on ESS voltage support. A proposed medium-voltage DC link to Marado was a simulation/research concept, not a deployed asset established by the paper. [4]

  • Original-project failure

    Korean government and National Assembly accounts attribute the original project's poor outcome to inadequate maintenance funding, difficulty sourcing replacement parts, and divided ownership and operational responsibility. The National Assembly cites a 2011-2016 project period and says the system ultimately stopped operating properly. [10][11]

  • Replacement safeguards

    The government says the new project is meant to address the earlier failure through adequate ESS and backup capacity, an explicit operating-and-maintenance budget, clearer responsibility, household heat pumps, and modern grid-forming controls. [10][11][12]

  • Replacement schedule and budget conflict

    The National Assembly's late-2025 review described a one-year 2026 KRW 22 billion plan, including KRW 9 billion for wind and KRW 11 billion for ESS through KEPCO. March 2026 reporting instead said design and supplier selection would extend into 2026-2027 and gave KRW 8 billion for 2026 and about KRW 14 billion total, indicating a revised scope or budget. [11][12]

Provenance

12 sources

Primary owner, government, university, supplier, and engineering sources are preferred. Archived references preserve claims whose original pages moved or disappeared.

  1. [1]
    Recovered Microgrid Projects record

    Internet Archive · Archived source · captured 2020-07-06

  2. [2]
  3. [3]
    Gapado Island works toward carbon-free future

    Korean Culture and Information Service · Primary source

  4. [4]
  5. [5]
    Operational experience of the ESS-based microgrid in Gapado Island

    CIRED / Korea Electric Power Research Institute · Primary source

  6. [6]
    Republic of Korea Microgrids: Overview and Case Studies

    Nautilus Institute for Security and Sustainability · Secondary research

  7. [7]
    Microgrid Solution project references

    Hyosung Heavy Industries · Primary source

  8. [8]
    Hyosung Heavy Industries research and development history

    Hyosung Heavy Industries · Primary source

  9. [9]
    Korea South-East Power wind-generation facility inventory

    Korea South-East Power Co. · Primary source

  10. [10]
    Policy explanation of the new Gapado carbon-neutral project

    Government of the Republic of Korea · Primary source

  11. [11]
    2026 budget analysis: Gapado RE100 project

    National Assembly Budget Office, Republic of Korea · Primary source

  12. [12]

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