Let’s actually do the math. Bear with me I am doing this on MS Calculator.
A 7.65 GW facility operating at full nameplate output for an entire year would generate 7.65 GW × 8,760 hours = 67.0 TWh/year.
Now the important variable is not “spare capacity.” It is capacity factor, heat rate, turbine configuration and actual dispatch.
Using EIA’s observed natural gas generation emissions intensity of roughly 0.8 to 0.9 lb CO2/kWh as a reasonable reference range, 67 TWh of continuous generation would put annual CO2 emissions somewhere in the neighborhood of 24 to 27 million metric tons before adjusting for the actual equipment and operating profile.
That alone demonstrates why saying “3 million tons per GW” and then simply multiplying by 0.75 because the plant supposedly has “25% spare capacity” is not sufficient.
Reserve capacity is not equal to capacity factor.
A plant can have excess installed capacity and still operate selected turbines at high utilization. Conversely, maintenance, load variation, renewable supplementation and demand fluctuations could substantially lower annual output. Without the actual turbine heat rates, combined cycle/simple cycle configuration, dispatch schedule and annual fuel consumption, nobody here can calculate the final emissions number from their keyboard.
So...33 million tons is a permitted ceiling, not guaranteed annual emissions.
17 million tons is also not established simply because somebody multiplied nameplate capacity by 0.75.
Both numbers require assumptions.
As for CO2 being “meaningless” because it supposedly isn’t pollution, that mixes two different environmental issues.
CO2 is primarily a greenhouse gas concern rather than a conventional local toxic pollutant like NOx, SO2, CO, VOCs or particulate matter. But fossil fuel turbines produce those pollutants as well, and EPA specifically regulates stationary combustion turbines for emissions including NOx and SO2. CO2 remains physically relevant because increasing atmospheric CO2 alters Earth’s radiative energy balance.
So the scientifically defensible position is actually pretty boring...We know the maximum permitted emissions.
We know the plant’s maximum generating capacity.
We do not yet know its eventual annual capacity factor or exact emissions intensity.
Therefore we cannot honestly claim it WILL emit 33 million tons, and we also cannot honestly claim it will be “extremely unlikely” to exceed some arbitrary percentage of that ceiling without more operating data.
Congratulations. We have successfully discovered uncertainty.
I realize this is considerably less exciting than “Amazon is killing Texans” or “CO2 is meaningless,” but unfortunately physics has terrible engagement metrics.
Sources:
EIA - CO₂ produced per kWh of electricity generation
EPA - Stationary gas and combustion turbines
