Generation

The generation stack covers all dispatchable and non-dispatchable capacity across the four modeled ISOs. Plant-level data drives short-run marginal costs, stepped bid curves, and capacity factor profiles.

Capacity buildout

Existing fleet

The base generator inventory is sourced from EIA-860 for all ISOs. For NYISO, the Gold Book provides supplementary forward projections. Each plant carries technology type, fuel, nameplate capacity, heat rate, and operational status.

CEM capacity integration

From the CEM start year onward, capacity expansion results are merged into the generator inventory. New builds are split into unit-level generators using node/technology average sizes to enable operational modeling.

Forecast

Policy drivers

RGGI’s declining emissions cap increasingly constrains fossil dispatch across all member states, raising effective thermal costs and accelerating economic retirements.

Data sources

Short-run marginal costs

SRMCs are computed per generator from heat rates, fuel costs, and emission costs. The heat rate hierarchy uses:

1. Plant-specific — EIA-923 reported heat rates (highest priority)
2. BA average — balancing authority mean for the technology
3. Technology average — national fallback

Thermal generators are expanded into stepped bid curves with configurable price/volume scaling per technology. Must-run generators (nuclear, certain hydro) can bid at or below zero to reflect system reliability requirements and incentive structures.

Data sources

Carbon costs — RGGI

The Regional Greenhouse Gas Initiative (RGGI) is a cap-and-trade programme covering CO2 from power plants in 12 northeastern states. Generators must purchase allowances at quarterly auctions; the cap declines annually.

In the model, the annual RGGI cap is prorated to the modeling period. CCR tiers release additional allowances when the carbon shadow price exceeds the triggers. Emissions intensity (tCO2/MWh) is plant-specific from heat rates and fuel CO2 content. Only generators located in RGGI member states face the constraint.

Renewable capacity factors and outages

Renewable generation uses time-varying capacity factors from weather-year data at the node level. Nuclear outages are sourced from NRC status data at the plant level. Technology-level forced outage rates are a placeholder (not currently modeled beyond nuclear).

Data sources

Demand response

Demand response is not currently modeled as a dispatchable resource in the Eastern Interconnection model. Large loads are included in the demand forecast but cannot be curtailed by the solver. This contrasts with the WECC model which includes 7 DR categories as price-responsive supply.

Assumptions and caveats

• Each thermal plant uses a 2-level bid step rather than a multi-step offer curve.
• Renewable and thermal load factors represent a historical weather year (2022 base).
• Hydro is not price responsive — output follows fixed historical profiles.

Data sources