Technical Manual · Power Grid
PLN Sumatera Grid Monitor — Methodology & Data Basis
Every topological choice, metric definition, node, voltage level, and data source behind the PLN Sumatera 150/275 kV interconnected grid monitor. This is a published-data reference monitor curated from RUPTL 2025-2034 and PLN AR 2024 — not a live SCADA feed, not an AC power-flow solver. All coordinates are city/plant centroids (approximate); all capacities are as published.
▶ Open the live grid monitor01 Purpose & engineering basis
The PLN Sumatera Grid Monitor is a published-data reference tool for data-center siting analysis. It answers three questions: where is high-voltage transmission capacity available in Sumatera, which major generating plants (coal, gas, hydro) serve each load zone, and how does the separate Batam-Bintan island grid connect to DC-relevant demand clusters (Nongsa Digital Park, Medan edge, Palembang edge).
The monitor renders a single-line diagram (SLD) approximation as an interactive Leaflet map. Nodes are substations, power plants, and DC clusters. Edges are transmission corridors at the published voltage level. No AC power-flow equations are executed; line impedances, short-circuit currents, and real-time loading are not modelled. The tool is a visual atlas and capacity reference, not a grid simulator.
Basis of content: RUPTL PLN 2025-2034 (Rencana Usaha Penyediaan Tenaga Listrik — PLN's 10-year power supply plan, publicly released), PLN Annual Report 2024, PLN UIP Sumbagut / Sumbagsel public capital-project filings, and public operator disclosures (Medco Power, b'right PLN Batam). Wikipedia plant infoboxes are used for geocoding cross-reference only — capacity figures always defer to RUPTL/PLN AR.
02 Inputs & user controls
The monitor exposes layer and region filters. Selections drive which node markers and transmission edges are rendered on the Leaflet map; the atlas table below always shows the full dataset.
| Control | Values | Effect |
|---|---|---|
| Voltage layer | 275 kV / 150 kV / Batam island / All | Filters edges to the selected voltage tier. 275 kV shows the north–centre–south backbone only; 150 kV shows regional distribution ties; Batam island isolates the separate islanded grid. |
| Node type | Substations / Plants / DC clusters / All | Filters circle markers by kind field (station, plant, dc). |
| Region / province | Aceh · North Sumatra · Riau · West Sumatra · Jambi · South Sumatra · Bengkulu · Lampung · Riau Islands | Highlights nodes in the selected province; map re-centres on the provincial bounding box. |
| Map click / popup | Any node marker | Shows node name, kind, voltage, capacity (MVA or MW), operator, province, notes, and confidence level from js/pln-sumatra-grid-data.js. |
| Scroll-wheel zoom | Enabled on first map click | Disabled on load to prevent accidental zoom during page scroll; activates on first map interaction. |
03 Methodology — topology & metric definitions
The grid is modelled as a node-edge graph stored in js/pln-sumatra-grid-data.js (window object PLN_SUMATRA_GRID). The schema mirrors the Java-Bali monitor for consistency. No power-flow mathematics are applied; all quantities are as published.
Topology structure
G = (V, E)
V — nodes: substations (GI/GITET), power plants (PLTU/PLTGU/PLTA), DC clusters
E — edges: transmission corridors tagged { from, to, voltage, island? }
North–centre–south backbone follows the published RUPTL corridor sequence: Aceh → Lhokseumawe → Pangkalan Susu → Binjai → Galang → Garuda Sakti (Pekanbaru) → Aur Duri (Jambi) → Muara Enim → Sutami (Lampung). Batam-Bintan edges are tagged
island:true and rendered as dashed cyan lines to visually separate the islanded system.RUPTL 2025-2034 · REFERENCE
Voltage level definitions (IEC 60038)
275 kV — Extra High Voltage (EHV): long-distance inter-regional bulk transmission backbone
150 kV — High Voltage (HV): sub-regional distribution and plant evacuation
20 kV — Medium Voltage (MV): on-premises DC campus intake (metered at PLN boundary)
Voltage nominal values per IEC 60038:2009 Table 1 (AC systems). PLN's 275 kV backbone is the highest-voltage public transmission tier in Sumatera; 500 kV is used in Java-Bali but not yet commissioned in Sumatera per RUPTL 2025-2034.IEC 60038 · STANDARD
Hydro availability factor (displayed metric)
Availability% = (Actual energy output [MWh] / (Installed capacity [MW] × 8 760 h)) × 100
Where shown in node popups, the availability figure is the RUPTL/PLN AR quoted annual availability rate for the specific plant. It is a published figure taken directly from PLN documents — the monitor does not compute it from hydrology data. Sumatera hydro plants (Asahan, Singkarak) quote ~45–60% annual availability given seasonal Batang Asahan / Singkarak inflow variability.PLN AR 2024 · REFERENCE
Tie-line flow (display only — no solver)
P_tie [MW] — not computed; displayed as directional annotation where published in RUPTL
Flow direction: South Sumatra (coal surplus) → North Sumatra (deficit) during peak demand
The monitor does NOT execute a DC or AC load-flow solver. Tie-line directions and approximate transfer limits are narrative annotations sourced from RUPTL congestion notes. Real transfer capacity is a function of line impedance, N-1 contingency limits, and real-time dispatch — none of which are modelled here.RUPTL 2025-2034 · REFERENCE
Reserve margin (displayed statistic)
Reserve margin% = ((Installed capacity [MW] − Peak demand [MW]) / Peak demand [MW]) × 100
The aggregate Sumatera reserve margin shown in the stats bar is sourced directly from RUPTL 2025-2034 projected figures for the Sumatera system. It is a planning margin, not a real-time operating reserve. PLN typically targets ≥ 30% planning reserve for the Sumatera system per RUPTL guidance.RUPTL 2025-2034 · REFERENCE
Node marker scaling
Plant radius [px] = max(5, min(12, sqrt(MW) / 2))
275 kV substation radius = 7 px · 150 kV substation radius = 5 px · DC cluster = 5 px
Marker radius is a visual encoding only — proportional to installed capacity for plants, fixed by voltage tier for substations. It is not a geographic scale.REFERENCE
04 Constants, node atlas & data provenance
The dataset contains 31 nodes across three system zones: North Sumatra (Sumbagut), Centre (Sumbagteng), South (Sumbagsel), and the separate Batam-Bintan (Barelang) island grid. Key plants and substations:
| Node | Kind | kV | Capacity | Fuel / type | Province | Confidence |
|---|---|---|---|---|---|---|
| PLTU Pangkalan Susu | Plant | 275 | 800 MW | Coal | North Sumatra | high |
| GITET Binjai | Substation | 275 | 500 MVA | — | North Sumatra | medium |
| GITET Galang | Substation | 275 | 500 MVA | — | North Sumatra | medium |
| PLTGU Belawan | Plant | 150 | 1 100 MW | Gas (CCGT) | North Sumatra | high |
| PLTA Asahan (Sigura-gura + Tangga) | Plant | 150 | 603 MW | Hydro | North Sumatra | high |
| GI Medan (metro) | Substation | 150 | 500 MVA | — | North Sumatra | medium |
| GITET Garuda Sakti (Pekanbaru) | Substation | 275 | 500 MVA | — | Riau | medium |
| PLTG Balai Pungut / Riau gas (Medco) | Plant | 150 | 130 MW | Gas | Riau | low |
| PLTA Singkarak | Plant | 150 | 175 MW | Hydro | West Sumatra | high |
| PLTU Ombilin | Plant | 150 | 200 MW | Coal | West Sumatra | medium |
| GITET Aur Duri (Jambi) | Substation | 275 | 500 MVA | — | Jambi | medium |
| PLTU Bukit Asam (Tanjung Enim) | Plant | 275 | 1 900 MW | Coal (mine-mouth) | South Sumatra | high |
| GITET Muara Enim | Substation | 275 | 500 MVA | — | South Sumatra | medium |
| PLTGU Gunung Megang / Sumsel gas (Medco) | Plant | 150 | 80 MW | Gas | South Sumatra | low |
| GI Palembang | Substation | 150 | 500 MVA | — | South Sumatra | medium |
| GITET Sutami (Lampung) | Substation | 275 | 500 MVA | — | Lampung | medium |
| PLTU Tarahan | Plant | 150 | 200 MW | Coal | Lampung | high |
| GI Bandar Lampung | Substation | 150 | 300 MVA | — | Lampung | medium |
| PLTGU Panaran (Medco Power) | Plant | 150 | 165 MW | Gas · island | Riau Islands | high |
| PLTU Tanjung Kasam | Plant | 150 | 110 MW | Coal · island | Riau Islands | medium |
| GI Batam Centre | Substation | 150 | 300 MVA | — · island | Riau Islands | medium |
| Batam DC cluster (Nongsa / data island) | DC | 20 | 40 MW | — · island | Riau Islands | medium |
Confidence levels: high = capacity from a published PLN filing or official operator disclosure; medium = area-geocoded from RUPTL/PLN AR regional data (coordinates accurate to city/district level); low = capacity or coordinate inferred from a province centroid or secondary industry source. All low-confidence entries are visually distinguished in the atlas notes column.
Batam-Bintan island grid: Operated by b'right PLN Batam (formerly Bright PLN Batam). System frequency and dispatch are fully independent of the mainland Sumatera interconnected system. Medco Power operates the Panaran I & II gas-fired peakers (165 MW combined) as the island's key dispatchable base-load. The Nongsa Digital Park subsea-cable DC hub is the primary large-load growth driver per PLN Batam's published capacity plans.
05 Outputs
| Output | Derivation | Unit | Interpretation |
|---|---|---|---|
| Substation count | Count of nodes where kind === 'station' | count | Total mapped 150/275 kV substations in the dataset. |
| Power plant count | Count of nodes where kind === 'plant' | count | Total mapped generation points (all fuels). |
| Mapped generation | Sum of node.mw for all plant nodes | MW | Total installed capacity represented in the dataset. Not a system total — only nodes curated from RUPTL are included. |
| 275 kV nodes | Count of nodes where voltage === 275 | count | Backbone EHV nodes in the mainland system. |
| Batam island generation | Sum of node.mw for nodes where island === true and kind === 'plant' | MW | Total mapped Batam-Bintan island generation capacity. |
| Medco-operated MW | Sum of node.mw for nodes where operator === 'Medco' | MW | Aggregate Medco Power generation footprint across Batam and Riau/Sumsel gas plants. |
| Interactive map | Leaflet.js render of node/edge graph | visual | Colour-coded by voltage (275 kV = dark blue, 150 kV = blue, Batam = dashed cyan) and node type (substation = blue, coal plant = red, hydro = cyan, gas = amber, DC = purple). |
| Atlas table | Sorted G.nodes array rendered as HTML table | visual | Full node list with capacity, province, and notes; province-sorted for regional scanning. |
06 Worked example — Batam-Bintan island grid reading
Reading the Batam-Bintan node cluster from published data, as the monitor presents it. This example shows how to interpret an islanded grid node set for DC-siting analysis.
- Identify the island cluster: Filter the map to "Batam island" layer. Four nodes appear: GI Batam Centre (150 kV, 300 MVA), GI Tanjung Uncang (150 kV, 250 MVA), GI Tanjung Uban / Bintan (150 kV, 120 MVA), and Batam DC cluster (Nongsa, 20 kV, ~40 MW estimated).
- Read generation: Two plant nodes — PLTGU Panaran / Medco Power (165 MW gas) and PLTU Tanjung Kasam (110 MW coal). Total mapped island generation: 275 MW.
- Isolation check: All island edges are tagged
island: trueand drawn as dashed cyan. No edge connects any Batam node to the mainland Sumatera 275/150 kV backbone — confirming the system is islanded (not synchronously interconnected). - DC load context: The Nongsa DC node is tagged
~40 MW estimated, confidence: medium— drawn from public DC operator filings. This represents the Singapore-adjacent AI/edge load footprint as of 2024. - Provenance check: Panaran / Medco Power =
confidence: high(Medco Power corporate disclosures + PLN Batam published capacity plan). Tanjung Uban =confidence: low— geocoded from Bintan island centroid, capacity from RUPTL regional estimate. - Planning reading: Island available capacity surplus ≈ 275 MW − 40 MW (DC) − other island loads ≈ constrained. The RUPTL 2025-2034 notes a Batam-island capacity addition programme to support the Nongsa data-centre cluster growth. This is a planning signal, not an operational dispatch figure.
Engineering reading: the Batam grid's islanded status means every MW of new DC load competes directly with the island generation base. Unlike the mainland Sumatera backbone, there is no synchronous import path. New subsea interconnection to the mainland or new gas/renewable capacity on Batam is the only relief — both are flagged in RUPTL 2025-2034 as medium-term projects.
07 References & standards
- RUPTL PLN 2025-2034 — Rencana Usaha Penyediaan Tenaga Listrik: primary capacity figures, plant commissioning schedule, transmission corridor plans (275 kV backbone, Batam capacity additions), and reserve margin projections for the Sumatera system.
- PLN AR 2024 — PLN Annual Report 2024: installed capacity totals by system (Sumbagut / Sumbagteng / Sumbagsel), plant-level operational performance including availability rates, and b'right PLN Batam island generation summary.
- PLN UIP Sumbagut / Sumbagsel filings — Unit Induk Pembangunan public project filings: substation coordinates, 275 kV backbone project status (Galang–Garuda Sakti corridor, Sutami upgrade).
- Medco Power corporate disclosures — Medco Power Indonesia public disclosures: Panaran I & II capacity (165 MW), Batam PPA counterparty (b'right PLN Batam), and Riau/Sumsel gas plant portfolio.
- b'right PLN Batam capacity plan — Batam island supply plan: Nongsa Digital Park load growth projection, PLTU Tanjung Kasam status, and new island generation pipeline.
- IEC 60038:2009 — IEC Standard Voltages: nominal voltage definitions for EHV (275 kV), HV (150 kV), and MV (20 kV) tiers used in node classification.
- IEC 60287 series — Electric cables — Calculation of current rating: referenced for MV (20 kV) feeder cable rating context at DC campus intake; not directly computed by the monitor.
- Dataset source —
js/pln-sumatra-grid-data.js(window.PLN_SUMATRA_GRID, dataset v2026-06-26): 31 nodes, ~20 edges, disclaimer tag embedded in the dataset object.
08 Assumptions & limitations
This is a curated visualization built from published PLN documents. The following limitations apply and are documented in the dataset's embedded disclaimer field:
Not a live SCADA feed. No real-time generation dispatch, line loading, voltage levels, or contingency status are shown. All data is static and sourced from documents published as of mid-2025.
Coordinates are approximate. Node coordinates are city/plant centroids from published addresses or geographic centroids — not precise GPS survey coordinates. Transmission line routes on the map are straight-line segments between node centroids, not actual tower-by-tower alignments.
Partial topology. The dataset covers major 275 kV backbone nodes and significant 150 kV substations. Not every 150 kV switching station, distribution substation, or 70 kV node in the Sumatera system is included. The atlas is a representative reference, not a complete network inventory.
Capacity figures are as published. Installed capacity (MW for plants, MVA for substations) is taken directly from RUPTL/PLN AR — it is not a net-available capacity figure, does not account for planned or forced outages, and does not reflect seasonal hydro derating. Low-confidence nodes are tagged explicitly.
No power-flow computation. The monitor does not run a DC or AC load-flow solver. Tie-line transfer directions and reserve-margin figures are narrative annotations from RUPTL — not the output of a network solver. For real power-system studies, use licensed PSS/E, PowerWorld, or PSCAD models with authorised PLN data.
This manual and the monitor are an engineering reference and data-centre siting aid; transmission adequacy assessments for a specific DC project require engagement with PLN's regional transmission unit (UIP/UID) and a connection study under PLN's published SPLN D3 connection standards.