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Running the numbers on EPA’s new CO2 regulations: natural gas combined cycle stacks up well

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Word started getting out late Thursday evening about the US Environmental Protection Agency’s carbon dioxide regulation for new natural gas and coal power plants. The New York Times has a rundown of the expected announcement (it hasn’t been officially announced at the time of posting). While carbon capture technology is being discussed for coal plants, it looks like combined cycle generation might be enough to get some power plants under the limit without needing any capture tech – at least for natural gas. This is because you’re extracting extra work through a steam turbine (in addition to the gas turbine) from the same unit of fuel.

Here is a breakdown of the CO2 regulations and how combined cycle generation stacks up (via my Twitter stream):

I used EIA’s emissions factors and heat rates for these calculations. I only found data for natural gas in my quick search of EIA and EPA, so if anyone has heat rates for coal-fired combined cycle feel free to send them in and I’ll update this post.

Update: Costa Samaras sent over CO2 emissions rates for coal-fired plants from a NETL analysis (PDF). Looks like even the IGCC plants from GE, Shell, and ConocoPhillips won’t hit the EPA targets without capture technology.

David Wogan About the Author: An engineer and policy researcher who writes about energy, technology, and policy - and everything in between. Based in Austin, Texas. Comments? Follow on Twitter @davidwogan.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. Noone 3:43 pm 09/20/2013

    I have little doubt that coal is being creatively (destructively) wiped out as a resource, so that natural gas can THEN be targeted as the only remaining “evil fossil fuel” choice. Even before coal is buried (!), “studies” of profound value (I’d pay a dime) are suggesting natural gas has to go because of wellhead, pipeline and connection leakage of methane. [This of course completely ignores the natural leakage of methane from fields left alone, but what the hey, we're really here to control resource pricing anyhow!]

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