Data vintage: Q1 2025 · Sources: MISO BPM-015 (Generator Interconnection) · MISO Tariff Attachments X & FF · DPP 2022 Group Study Results (pub. 2023)
MISO Network Upgrade Cost Framework
1
Stage 1 Direct Assignment
Costs at POI — substation work, gen lead, protection upgrades. Solely assigned to requesting project. No cost sharing. Typical: $3–25M for wind/solar, $5–40M for large thermal.
BPM-015, Section 4.2 Direct Costs
2
Stage 2 Shared Upgrades
Higher-voltage upgrades triggered by multiple projects in study group. Allocated via injection shift factor (ISF) analysis. Typical per-project share: $20–150M. MISO South averages 2–3× MISO North.
BPM-015, Section 4.3 ISF Allocation
3
Stage 3 Stability Upgrades
Series capacitors, dynamic reactive devices (SVCs, STATCOMs). Triggered by large wind farms or high ISC ratios. Rare but expensive: $15–90M. Allocated by sensitivity factor to the stability violation.
BPM-015, Section 4.4 Stability
4
Transmission Security Deposit
Posted at IA execution. Wind: $30/kW. Solar/Storage: $25/kW. Forfeited if project withdraws after construction milestone. Refunded pro-rata at COD. 50% refund at substantial completion.
MISO Tariff, Section 6.1.1 TSD
5
MVP Cost Allocation
Large proactive transmission (like Thumb Area) costs socialized across all MISO load — not charged to specific generators. Benefits wind developers broadly with no direct cost. Postage-stamp allocation across state boundaries.
MISO Tariff, Attachment FF MVP
Cost Benchmarks by Technology & Region — DPP 2022 Data
| Technology | Region | Avg Stage 1+2 Cost | TSD ($/kW) | Typical Total Range |
|---|
| Onshore Wind | MISO North (MN, ND, SD) | $30,000–$80,000/MW | $30/kW | $8–45M total |
| Onshore Wind | MISO Central (IL, IN) | $50,000–$130,000/MW | $30/kW | $12–65M total |
| Utility Solar | MISO Central (IL, IN, IA) | $35,000–$90,000/MW | $25/kW | $8–50M total |
| Utility Solar | MISO South (AR, LA, MS) | $60,000–$150,000/MW | $25/kW | $15–80M total |
| Solar + BESS Hybrid | All regions | $45,000–$110,000/MW | $25+$25/kW | $12–70M total |
| Standalone BESS | All regions | $20,000–$60,000/MW | $25/kW | $5–30M total |
| Offshore Wind (Great Lakes) | Michigan coast (future) | Est. $200,000–$350,000/MW | $30/kW | $80–250M total |
ERIS vs. NRIS — Interconnection Service Types
Service Type A
Energy Resource Interconnection Service (ERIS)
Project can inject up to nameplate capacity into grid for energy purposes. No deliverability guarantee. Cannot count toward PRA (Planning Resource Auction) capacity obligation without further study. Faster path, lower cost. Suitable for merchant energy-only projects and REC contracts.
MISO Tariff, Attachment X, ERIS
Service Type B
Network Resource Interconnection Service (NRIS)
Full deliverability. Project can count toward LRZ capacity requirement in PRA. Requires passing full deliverability study in Stage 3. Higher upgrade costs — can be $10–80M additional in MISO South. Required for LSE capacity contracts and participation in capacity market.
MISO Tariff, Attachment X, NRIS
Cost Adder
NRIS Study Cost in Constrained Areas
Selecting NRIS adds Stage 3 deliverability analysis. Can add $10–80M in allocated costs for projects in constrained areas (MISO South LRZ 9). Many developers choose ERIS + REC-only contracts, especially when capacity market prices are low (LRZ 1/2: $0/MW-day).
MISO BPM-015, Section 4.4
Post-COD Option
ERIS → NRIS Upgrade Path
Projects can upgrade service type post-COD via MISO's Supplemental Filing process. Fee: $500k study deposit + re-study costs. Allowed once per project. Useful if PRA capacity prices rise substantially, converting an energy-only project to a capacity resource.
MISO Tariff, Section 7.6 Supplemental
MISO Interconnection Cost Trends
2019
Baseline — MISO North Wind at ~$40k/MW
MISO North wind well-served by existing infrastructure. ISF-allocated costs minimal in ND/MN where Thumb Area and MVP transmission provided headroom. Solar in IL near $50k/MW with limited shared upgrades.
2021
MISO South Spike — Reaches ~$90k/MW Average
MISO South (LA/MS/AR) cost averages rise to ~$90k/MW as Entergy SO transmission saturates. Study results delay 18+ months. Solar+BESS applications surge in constrained area, triggering higher shared upgrades.
2023
DPP 2022 Stage 2 Results Published
Average shared NUC cost ~$65k/MW across all MISO regions. MISO South projects averaging $140k/MW — nearly 2.5× MISO North. 30% of MISO South applicants voluntarily withdrew on cost results.
2024
DPP 2023 Results Pending — MISO Central Rising
Pre-assessments suggest MISO Central (IL/IN) rising to ~$85k/MW due to increased solar density and data center load interaction. FERC Order 2023 milestones applying for first time — expected to filter lowest-quality applicants.
2025
LRTP Series 2 Construction — Relief for MISO South
MISO LRTP Series 2 construction begins — $3.2B in SE region upgrades. Expected to relieve MISO South structural constraints, reducing project-level DPP allocated costs by ~20% in LA/MS by 2028.
2026
MISO-SPP JTIQ Upgrades Online
MISO-SPP seam capacity increases ~15 GW. Projects near IA/MN/KS/OK border expected to see lower NUC allocations as seam transmission relieves north-to-south flow pressure. MISO North wind cost outlook improved.