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>Much more encouragingly... Natural-gas consumption in the United States increased by 10% last year... So, I wouldn't say that statement is absolutely encourag

>Much more encouragingly... Natural-gas consumption in the United States increased by 10% last year... So, I wouldn't say that statement is absolutely encouraging since any unburned Natural Gas releases methane (i.e. "methane slip"), which is 80-times more potent than CO2 in terms of planetary greenhouse effects. (1) Though, at least there's a solution: completely burn your natural gas. But is this to much to ask of the consumer? It's not necessarily in their control. I imagine it will take a healthy amount of regulation of gas consuming products, but I know that every time I turn my crappy gas Kenmore (""elite"" - don't buy one) range, the gas runs for 3-4 seconds without burning, and my gas heater pilot has a few second delay before the flame catches, and god only knows how efficient these actually are burning the gas when operating. Multiply that by several million (2), and I cringe at the prospects. The further we go, the more attractive Nuclear becomes to me. Looking at the plot, I think the U.S. should work (invest - even at a loss) directly with India to establish Nuclear plants ASAP as their hunger for energy grows with an already massive population. It's going to get ugly if we don't. 1.) https://www.edf.org/media/new-study-finds-us-oil-and-gas-methane-emissions-are-60-percent-higher-epa-reports-0 https://www.edf.org/media/new-study-finds-us-oil-and-gas-met... 2.) https://www.statista.com/statistics/221447/gas-range-and-oven-shipment-forecast-in-the-us-by-quarter/ https://www.statista.com/statistics/221447/gas-range-and-ove...

Scoundreller 8y ago
A condensing (“high-efficiency”) extracts something like 95% of the heat with consistent blue flames. The efficiency is definitely there. Newer gas water heaters have a similar efficiency. If you want to improve your cooking efficiencies, pre-thaw your frozen stuff in the fridge, pre-heat it using the microwave and/or use a pressure-cooker. Cool multiple meals in one big batch and then portion them out for the week.
- CydeWeys 8y ago
  They're referring to combustion efficiency, not thermodynamic efficiency, i.e. what percentage of the natural gas is completely combusted and released into the atmosphere as CO2.
  - Scoundreller 8y ago
    And I’m running on the assumption that a furnace that’s designed to squeak out the energy within the steam from combustion will also ensure a good continuous flame that starts almost instantly. If it takes 3 seconds to start, and runs for 15 minutes, that’s 0.33% of time spent starting, and it’s probably more of a flare for those first 3 seconds than unmetered gas escape.
    - CydeWeys 8y ago
      Overall I agree with you that it's likely not significant, but the OP is using figures stating that methane is 80X worse of a greenhouse gas than CO2. So you're missing some critical figures in your math; that 0.33% of the time spent starting could represent a much higher emission volume (though in practice I don't think it does because I don't think full flow is triggered until the flame sensor is triggered).
CydeWeys 8y ago
We can do some simple math here to determine that it's probably not a big deal. What is the average length of time that your Kenmore stovetop is on? Assuming it's, say, 15 minutes (which frankly could be short depending on what kind of cooking you do), then it's emitting CO2 for 900 seconds with each use and emitting methane for 3 seconds with each use. If we want to normalize that to CO2-equivalent, then it's 900 CO2-seconds plus 3*80 CO2-seconds for the methane -- a non-trivial amount to be sure, but still only 27% more. Likewise, how often does your gas heater re-ignite? And are you sure that it's releasing gas at full pressure prior to ignition? From what I remember of mine, it releases a slow stream of gas, has a sensor to determine that the flame has caught, and then cranks on the full stream of gas. It might be dangerous to jump straight to full stream before verifying ignition, so you can imagine why that might not be done. Again, assuming a typical 15 minute load cycle here (which might be low), and a much lower pressure before the flame catches, it's probably a negligible amount. Overall I'm more worried about gas leaks in the distribution pipelines, as those are everywhere and run 24/7, not just in the few seconds before a flame catches.
- mojomark 8y ago
  That's a good back-of-the-envelope assesment, thanks. Also, very good point about the infrastructure leakage. I didn't know much about the issue, so I took a quick look (1). Iagree - that persistant problem is probably a much bigger issue than intermittent end-use leakage. My basic point was simply that the U.S. using more natural gas isn't necessarily "great news".

Scoundreller 8y ago

A condensing (“high-efficiency”) extracts something like 95% of the heat with consistent blue flames. The efficiency is definitely there. Newer gas water heaters have a similar efficiency. If you want to improve your cooking efficiencies, pre-thaw your frozen stuff in the fridge, pre-heat it using the microwave and/or use a pressure-cooker. Cool multiple meals in one big batch and then portion them out for the week.

CydeWeys 8y ago
They're referring to combustion efficiency, not thermodynamic efficiency, i.e. what percentage of the natural gas is completely combusted and released into the atmosphere as CO2.
- Scoundreller 8y ago
  And I’m running on the assumption that a furnace that’s designed to squeak out the energy within the steam from combustion will also ensure a good continuous flame that starts almost instantly. If it takes 3 seconds to start, and runs for 15 minutes, that’s 0.33% of time spent starting, and it’s probably more of a flare for those first 3 seconds than unmetered gas escape.
  - CydeWeys 8y ago
    Overall I agree with you that it's likely not significant, but the OP is using figures stating that methane is 80X worse of a greenhouse gas than CO2. So you're missing some critical figures in your math; that 0.33% of the time spent starting could represent a much higher emission volume (though in practice I don't think it does because I don't think full flow is triggered until the flame sensor is triggered).

CydeWeys 8y ago

We can do some simple math here to determine that it's probably not a big deal. What is the average length of time that your Kenmore stovetop is on? Assuming it's, say, 15 minutes (which frankly could be short depending on what kind of cooking you do), then it's emitting CO2 for 900 seconds with each use and emitting methane for 3 seconds with each use. If we want to normalize that to CO2-equivalent, then it's 900 CO2-seconds plus 3*80 CO2-seconds for the methane -- a non-trivial amount to be sure, but still only 27% more. Likewise, how often does your gas heater re-ignite? And are you sure that it's releasing gas at full pressure prior to ignition? From what I remember of mine, it releases a slow stream of gas, has a sensor to determine that the flame has caught, and then cranks on the full stream of gas. It might be dangerous to jump straight to full stream before verifying ignition, so you can imagine why that might not be done. Again, assuming a typical 15 minute load cycle here (which might be low), and a much lower pressure before the flame catches, it's probably a negligible amount. Overall I'm more worried about gas leaks in the distribution pipelines, as those are everywhere and run 24/7, not just in the few seconds before a flame catches.

mojomark 8y ago
That's a good back-of-the-envelope assesment, thanks. Also, very good point about the infrastructure leakage. I didn't know much about the issue, so I took a quick look (1). Iagree - that persistant problem is probably a much bigger issue than intermittent end-use leakage. My basic point was simply that the U.S. using more natural gas isn't necessarily "great news".