Posted By Ona on 10/02/2009 2:22 PM
J08M3 ~ I did not take it personally, just wanted to get on my soap box :o)
Dana1 ~ while my carbon footprint did play into my decision in selecting geothermal (with respect to environmental considerations), it was by far not my only environmental consideration. I will admit that I am a moderate environmentalist (even though it appears to have become a negative term over the past 9 years). But I have not jumped on the “climate change is the MOST important environmental factor” bandwagon. Don’t get me wrong, I know and understand that climate change is scientific fact, but there are several other air quality issues which have direct human health impacts which I considered.
SO2 (sulfur dioxide), NOx (nitrogen oxides) and PM (particulate matter) have been proven to result in negative health effects like asthma, heart attacks, and other respiratory diseases/issues. Using fuel oil resulted in higher SO2, NOx and similar PM. If I convert my btu’s to the equivalent amount of natural gas, it would result in higher NOx and PM. This info coupled with the fact that my State (New York) gets most of its electricity from hydro, nuclear and gas led me to the local decision of geo. In addition, I do not have natural gas available to me in my rural home.
The particulate emissions of NG in a modern heating system burner is miniscule- fears of acute health hazards related to NG particulates in ANY case should be relegated primarily to cooking burners & unvented hot water heaters (the latter of which is mostly illegal in the US, but common in parts of Europe), where the emissions are larger and occur inside of conditioned space, where the dilution factor is lower.
http://www.liebertonline.com/doi/pdf/10.1089/ees.2007.0188
Acute health issues related to particulate emissions from heating systems may be a (secondary) issue in high-density housing in cities, but never in rural areas, or even postage stamp lot single family housing, where the outdoors dilution factor is still quite huge.
Similarly, the NOx emissions of newer condensing heating-appliance burners is a small fraction of that of old-skool burners, and less of a localized acute health issue than cooking burners & unvented HW heaters. For condensing burners it's already down to under 50ppm for many (from 150-200ppm in the good old dayz), with regulation limits targeting 15-30ppm already under consideration in CA:
http://www.aqmd.gov/pub_edu/notice_1111_Sept_9_09.html
If you care about acute local NOx, CA-compliant burners would a the place to start looking. But I'm not sure the grid-average for NY gas burning turbines (or the concrete that went into the hydro-dams & nukes) is low enough that it's a clear argument that geo has a broad overall lower NOx emission than heating with NG. (It might or might not.)
But the real deal is, you're not on a gas main, and therefore never on the table for you. (Whereas some here are trying to get a handle on geo vs. NG option, which is what I was addressing.)
Gas might have been lower
cost all around, with better energy price security than oil/propane, as is the price security on your less fossil-dependent local grid (now that we're in the post-acid rain control era). This makes geo a more reasonable & green option for you compared do say, someone in Salt Lake City where NG is cheap, and the grid is heavily coal-fired, (even though the cost of operation is lower for geo there than even their cheap NG.) In SLC the upfront cost of geo is higher, and verditude lower, by any emissions standard.