costingother
Screening-stage parametric estimate of substation CAPEX split, annual O&M, total annual cost, and levelized cost per MWh of energy throughput.
Rated active power capacity to be transformed/handled by the station (screening value).
min 1 · max 2000 · step 1 · MW
Select the representative HV class; used as a cost multiplier.
Classical station options with different cost structures and multipliers.
Annual O&M cost
Fixed O&M estimated as a fraction of CAPEX
Total CAPEX
Total installed capital cost of the station (screening estimate)
Annual energy throughput
Expected annual energy delivered by the station
Specific CAPEX (scaled & clamped)
Parametric estimate at the selected voltage class and station type
CAPEX split: Transformers
Transformers portion of total CAPEX
CAPEX split: Switchgear
Switchgear (AIS/GIS) portion of total CAPEX
CAPEX split: Civil & buildings
Civil works, buildings, foundations, site works
Expected average utilization of the station as a percent of rated power (0–100%).
min 0 · max 100 · step 0.1 · %
Economic lifetime of the station (years) for annualization.
min 1 · max 80 · step 1 · years
discount_rateLevelized cost of throughput
Levelized cost per MWh of energy throughput
Calculator context
This calculator provides a screening-stage cost estimate for an electrical power transformation station (substation) as a function of rated power, utilization, voltage class, and station configuration (AIS/GIS; indoor/outdoor). It is intended for early project development to rapidly compare options and produce a transparent CAPEX split and levelized cost per MWh of throughput.
The approach follows common energy-cost methodology patterns used in industry and public techno-economic sources (e.g., IRENA/IEA costing conventions for annualization and levelized metrics) and aligns with typical substation cost decomposition used in NREL/DOE-style parametric infrastructure estimates (while recognizing that actual EPC pricing is highly site- and utility-specific).
The model uses a reference specific CAPEX adjusted by discrete option multipliers (voltage, technology) and an economy-of-scale exponent. Key equations:
CAPEX split is computed as fixed fractions (by station type) for transformers, switchgear, civil/buildings, protection & control, installation/commissioning, engineering/owner’s costs, with contingency as the remaining share.
43 assumptions used in the calculations
Prevents division-by-zero and undefined operations in scaling and levelized-cost calculations.
Explicit zero constant to avoid inline numeric literals.
Market range 0
Explicit unity constant to avoid inline numeric literals (e.g., for shares summing to 1).
Market range 1
Explicit 100 constant for percent-to-fraction conversion.
Market range 100
Converts MW to kW for specific CAPEX multiplication.
Market range 1000
Reference size for the parametric cost curve; represents a mid-size grid connection station.
Represents an order-of-magnitude installed cost for an outdoor AIS station at HV class and reference size before multipliers and scaling.
Lower voltage classes generally require less insulation/clearance and lighter switchgear, reducing CAPEX.
Baseline multiplier for HV class.
EHV stations typically require higher insulation levels, larger clearances, and higher-rated equipment.
Very high voltage stations have materially higher equipment and civil requirements.
Baseline station type (outdoor AIS).
Indoor AIS typically adds building/civil scope and may increase installation complexity.
GIS equipment typically carries higher unit costs but may reduce footprint; overall tends to be higher CAPEX.
Captures economies of scale: larger stations often have lower specific CAPEX.
Market range -0.05 to -0.30
Prevents unrealistic low outputs from scaling at very large sizes.
Prevents unrealistic high outputs from scaling at very small sizes or extreme multipliers.
Represents fixed annual O&M (inspection, maintenance, spares) as a fraction of CAPEX.
Baseline O&M multiplier for outdoor AIS.
Indoor stations may require additional HVAC/building upkeep and access constraints.
GIS and indoor configurations can add maintenance specialization and building systems.
Captures mild economies of scale for fixed O&M with increasing station size.
Market range -0.02 to -0.10
Prevents unrealistically low fixed O&M fractions under scaling.
Prevents unrealistically high fixed O&M fractions under scaling.
Transformer(s) are typically the largest equipment cost item in many stations.
Switchgear and bays are a major cost block; higher for GIS.
Civil/site works include foundations, cable trenches, roads, drainage, fencing.
Protection, control, SCADA, communications, metering.
Installation, testing, commissioning, temporary works.
Engineering, project management, permitting, owner’s costs (screening).
Indoor AIS tends to shift budget toward buildings/civil and away from transformers as a share.
Indoor layouts may modestly increase switchgear share (enclosures, buswork).
Indoor configuration typically adds building and related civil works.
No systematic change assumed at screening stage.
No systematic change assumed at screening stage.
Engineering/owner’s share assumed unchanged at screening stage.
GIS tends to increase switchgear share; transformers become a smaller share of total.
GIS equipment commonly increases switchgear share due to higher unit costs.
Indoor GIS typically requires buildings and auxiliary systems; increases civil/buildings share.
Slight increase allowed for additional monitoring/interlocks typical in GIS implementations.
GIS can reduce some on-site assembly/installation scope (more factory-assembled), reducing installation share.
Engineering/owner’s share assumed unchanged at screening stage.
Standard hours per year for energy throughput calculation.
Market range 8760