Levelized cost of electricity for gas-fired generation, with the gas demand it creates.
Capital recovery factor, the full LCOE build-up, why capacity factor drives peaker economics, and converting MW of load into gas demand.
LCOE (levelized cost of electricity) is the average revenue per MWh a plant must earn over its life to recover capital, fixed and variable O&M, fuel and any carbon cost. It lets you compare a gas plant against other generation on a single $/MWh basis.
Capital cost is annualized with the capital recovery factor CRF = r(1+r)^n / [(1+r)^n − 1], then capital and fixed O&M are divided by annual generation (8760 × capacity factor). Variable O&M, fuel (heat rate × gas price / 1000) and carbon are added to give $/MWh.
Capital recovery and fixed O&M are fixed dollars per year spread over however much energy the plant produces. At 10% capacity factor those costs are spread over one sixth the output of a 60% plant, so LCOE rises sharply. This is why peakers are evaluated on capacity payments rather than LCOE alone.
Fuel burn is heat rate × generation. A 418 MW combined-cycle plant at 6,431 Btu/kWh and 60% capacity factor burns about 38 MMscf/d of pipeline gas on an average day, and about 63 MMscf/d at full load - size firm transport on the maximum day. This calculator reports MMscf/d and Bcf/yr so the power project can be translated into gathering, processing and transport demand.
The default is 53.06 kg CO2/mmBtu from EPA 40 CFR 98 Subpart C, Table C-1 (natural gas, weighted U.S. average) - the GHG-reporting basis, which is the right one here because the factor is used to price carbon. The gas heating value default of 1,026 Btu/scf comes from the same table. For reference, EPA AP-42 Table 3.1-2a gives 110 lb/MMBtu (49.90 kg/MMBtu) for gas turbines specifically, about 6% lower.