Island Grid Interconnection
The Philippines operates three main grids (Luzon, Visayas, Mindanao) plus approximately 500 off-grid island systems serviced by NPC -SPUG and local electric cooperatives. Interconnection projects physically link off-grid island systems to the main grids, eliminating the need for costly missionary generation and the UC-ME cross-subsidy that funds it [PEP 2023-2050 Vol. II, p.99, 2023]. See Universal Charge for Missionary Electrification (UC-ME) for the UC-ME graduation and rationalization policy context.
Major Backbone Transmission Projects
Infrastructure strengthening the three main grids as of mid-2023 [PEP 2023-2050 Vol. II, pp.81–85, 2023]:
| Project | Voltage | Capacity | Status (mid-2023) | Target |
|---|---|---|---|---|
| HSJ 500-kV — Heneral Sto. Niño–San Jose (Luzon backbone) | 500 kV | 2,000 MW loading | Energized 27 May 2023; 10 delays from June 2019 | February 2024 (full energization) |
| CNP 230-kV Stage 3 — Cebu–Negros–Panay (Visayas backbone) | 230 kV | 270 MW commissioned / 800 MW design | 97.2% complete; 7 delays from December 2020 | March 2024 |
| MVIP — Mindanao–Visayas Interconnection Project | — | 450 MW target | 99.3% complete; 10 delays from December 2020 | January 2024 |
MVIP connects Mindanao to the Visayas grid for the first time, realizing the “One Grid Philippines” vision. See Mindanao-Visayas Interconnection Project (MVIP) .
Island-to-Mainland Interconnection Projects
Four priority projects to graduate specific island systems from missionary electrification status [PEP 2023-2050 Vol. II, pp.101–102, 2023]:
| Project | Route | ERC Status | Target Completion |
|---|---|---|---|
| CCIP — Camarines Sur–Catanduanes 69-kV | Catanduanes → Luzon via Camarines Sur | Filed June 2022 (Case 2022-044 RC); awaiting ERC approval | December 2030 |
| BMIP — Batangas–Mindoro | Mindoro → Luzon via Batangas (Pinamucan 500-kV ↔ Calapan) | ERC approved November 2022 | Sept 2027 (NGCP accelerated target: 2025) |
| QMIP — Quezon–Marinduque | Marinduque → Luzon via Quezon | Filed July 2021 (Case 2021-049 RC); awaiting ERC approval | December 2030 |
| PMIP — Palawan–Mindoro (two-stage) | Mainland Palawan; future ASEAN Power Grid link | Filed March 2019, Stage 1 (Case 2019-022 RC); awaiting ERC approval | February 2033 |
The PMIP also aligns with the ASEAN Power Grid (APG) vision under the BIMP-EAGA regional interconnection framework. See ASEAN Energy Cooperation — Philippines Engagement .
DC2022-05-0016 Annex A — Full Indicative Project Pipeline
DC2022-05-0016 (May 2022) listed 18 indicative and potential interconnection projects drawn from TDP 2022-2040 Chapter 11 (pp.143–158). The 4 priority projects above (BMIP, CCIP, QMIP, PMIP) are the ones with ERC filings; the remaining 14 are “for further study” [DC2022-05-0016, Annex A, 2022-05]:
| Project | Distribution Utility | Target / Status |
|---|---|---|
| Batangas–Mindoro | ORMECO, OMECO | Feb 2026 — filed to ERC |
| Palawan–Mindoro | ORMECO, OMECO, PALECO | Feb 2028 — filed to ERC |
| Quezon–Marinduque 69kV | MARELCO | Dec 2025 — filed to ERC |
| Camarines Sur–Catanduanes 69kV | FICELCO | Dec 2025 — filed to ERC |
| Zamboanga–Basilan 69kV | BASELCO | Dec 2030 — for further study |
| Ticao Island | TISELCO | For further study |
| Masbate Island | MASELCO | For further study |
| Tablas Island | TIELCO | For further study |
| Lubang Island | LUBELCO | For further study |
| Busuanga Island | BISELCO | For further study |
| Bantayan Island | BISELCO | For further study |
| Siquijor | PROSIELCO | For further study |
| Camotes Island | CELCO | For further study |
| Semirara Island | ANTECO | For further study |
| Dinagat Island | DIELCO | For further study |
| Siasi Island | SIASELCO | For further study |
| Sulu Island | SULECO | For further study |
| Tawi-Tawi | TAWELCO | For further study |
Note: Two cooperatives share the abbreviation “BISELCO” — Busuanga Island EC and Bantayan Island EC. Both are distinct entities.
TransCo SIGSO Preparatory Role
The DOE designated TransCo as the System Operator (SO) for off-grid power systems with two or more suppliers under DC2021-11-0039. In August 2023, TransCo commenced stand-alone operations for the Mindoro Grid — a critical precursor to the BMIP interconnection. TransCo is finalizing the Mindoro Grid Protection Philosophy and Setting Guidelines and will formulate an SO exit/phase-out plan upon BMIP completion [PEP 2023-2050 Vol. III, p.48, 2023].
Off-Grid Electrification Hierarchy
Interconnection is the preferred, lowest long-run-cost solution for major island systems with sufficient load and a feasible submarine cable route. Where interconnection is not viable within the planning period, the government applies a tiered approach [PEP 2023-2050 Vol. II, p.103, 2023]:
- Grid interconnection — for islands meeting load and route feasibility criteria
- Microgrids — for geographically isolated areas with concentrated loads (see Microgrid Policy and Off-Grid Electrification )
- PV-SHS — for dispersed households where grid and microgrid are not cost-effective
Luzon–Visayas HVDC Enhancement
Beyond the existing 440+440 MW HVDC links, the DOE has proposed a Luzon–Visayas High Voltage Direct Current (HVDC) Bipolar Operation project to enable greater power import/export between the Luzon and Visayas grids. This is a long-term capacity upgrade — not yet in the TDP as a committed project — aimed at optimizing cross-grid dispatch as both grids develop large VRE portfolios [PDP 2023-2050, Ch.3 Sec.2.7, p.108, 2025].
Transmission Planning Framework
NGCP is required to incorporate island interconnection projects into the Transmission Development Plan (TDP) — submitted to and approved by DOE on a rolling basis. DO2017-04-0004 designated TransCo as Grid Owner to participate in TDP preparation, review, and evaluation. The Smart and Green Grid Plan (SGGP) — formulation commenced May 2023, target Q1 2024 — further informs grid expansion priorities and OSW connection requirements. See Transmission Development Plan (TDP) and Smart and Green Grid Plan (SGGP) .