Multi-region capacity expansion planning for the Southwest Power Pool (SPP) and ISO New England (ISO-NE) footprints — each a cut of the Eastern Interconnection PSS/E case, reduced via subgraph-based Ward reduction, then solved for multi-year generation and transmission expansion. Choose a region below to see its studies.
The analysis follows a six-stage pipeline, each producing intermediate files consumed by the next.
Explore the SPP capacity expansion results across three demand growth scenarios — pick a study below.
$298.5B total cost. 1,304 buses, 3,623 lines. DCOPF with Gurobi barrier. 1,843 MWh load shedding (economically optimal).
High demand scenario using the updated 1,304-bus network with 7% annual load growth.
Conservative demand scenario using the updated 1,304-bus network with 1.5% annual load growth.
The same pipeline applied to ISO-NE (PSS/E area 101): the New England network reduced to 440 buses, solved across three ISO-NE load-growth scenarios — pick a study below.
$76.2B total cost. 440 buses, 1,278 lines. 68.9 GW final capacity. ISO-NE 2024 CELT mid load growth. No load shedding.
$104.6B total cost. 117.3 GW final capacity. High-electrification demand path for the 440-bus ISO-NE network.
$66.8B total cost. 56.0 GW final capacity. Conservative ISO-NE demand path with 0.9% annual load growth.
The full Eastern Interconnection PSS/E model contains 92,511 buses — far too large for direct optimization. This project reduces the network to 1,304 buses using subgraph-based Ward reduction while preserving electrical fidelity, then solves a multi-year capacity expansion optimization using Gurobi.
Starting with the 2024 ITP PSS/E RAW file (92,511 real buses), the 10-step pipeline applies star bus area fix, SPP-23 filtering, island removal, subgraph consolidation (transformers + low-Z bus ties + short lines <2mi), radial absorption, degree-based retention (≥69 kV), and DC Ward reduction to produce 1,304 buses and 3,623 equivalent lines. Gen/load conservation is exact (77,910 MW gen, 58,438 MW load); generators are distributed to retained buses by load-flow (LF) weights.
The capacity expansion model optimizes generation and transmission investment across 6 planning years (2024-2049) and 17 time blocks. Technologies include wind, solar, gas CC/CT, coal, nuclear, and hydro. DC optimal power flow enforces network constraints.
The model covers 23 official SPP RTO areas (MMWG v43). Areas 511 (AECC) and 540 (GMO) are excluded (no retained buses). All external areas including 327, 330, 356, 635 are treated as boundary with tie-line fixed injections.
Detailed technical documentation covering every stage of the pipeline.
Complete reference: PSS/E parsing, Ward reduction, CEP dataset, optimization, and dashboards.
Visual overview of the SPP CEP project, methodology, and key findings.
ISO New England reference: area-101 reduction, gen-tech sources, capacity factors, and CEP results.
Visual overview of the ISO-NE CEP study, scenarios, and key findings.