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RobertSmalls · 09-20-10, 01:29 PM

I'd like to do a similar per-appliance breakdown of my natural gas usage so I know where to try to conserve. I'll measure the dryer and oven next time I use them, but I have a feeling almost all of my gas is used for hot water, plus a big bump in the winter for the furnace.

I would love a DIY hybrid solar thermal hot water tank, and I'd also like to cancel my service with the gas company eventually. My goal is to use so little gas that it's not worth the $150/yr hookup fee or the $192/yr minimum billing. It's not going to happen any time soon, because I don't fancy replacing four of my major appliances just to save $150/yr. But IF I had solar hot water and all four gas appliances failed at the same time, or if I were doing new construction, I'd go for it.

Another dense spreadsheet. Column E is the monthly service charge / hookup fee for each utility, and column D is the cost of energy + delivery.

Cell F3 is a lie. That's what my electric consumption's CO2 footprint would be on grid average electricity, but my utility offers a 100% renewable plan, so cell F3 should hold some value close to zero.

I find columns G&H very interesting. The CO2/MJ figures include petrol refining and electric transmission. The fact that petrol is so much more expensive than natural gas speaks to the relative scarcity of and lack of substitutes for the former.

A heat pump would need a CoP of 3.2 to match the energy cost of a 95% efficient natural gas furnace, or 3.1 to match the CO2 output. Hmm. Natural gas is good stuff.

09-20-10, 01:29 PM	#9
RobertSmalls Journeyman EcoRenovator Join Date: May 2009 Location: Buffalo, NY Posts: 344 Thanks: 3 Thanked 17 Times in 15 Posts	I'd like to do a similar per-appliance breakdown of my natural gas usage so I know where to try to conserve. I'll measure the dryer and oven next time I use them, but I have a feeling almost all of my gas is used for hot water, plus a big bump in the winter for the furnace. I would love a DIY hybrid solar thermal hot water tank, and I'd also like to cancel my service with the gas company eventually. My goal is to use so little gas that it's not worth the $150/yr hookup fee or the $192/yr minimum billing. It's not going to happen any time soon, because I don't fancy replacing four of my major appliances just to save $150/yr. But IF I had solar hot water and all four gas appliances failed at the same time, or if I were doing new construction, I'd go for it. Another dense spreadsheet. Column E is the monthly service charge / hookup fee for each utility, and column D is the cost of energy + delivery. Cell F3 is a lie. That's what my electric consumption's CO2 footprint would be on grid average electricity, but my utility offers a 100% renewable plan, so cell F3 should hold some value close to zero. I find columns G&H very interesting. The CO2/MJ figures include petrol refining and electric transmission. The fact that petrol is so much more expensive than natural gas speaks to the relative scarcity of and lack of substitutes for the former. A heat pump would need a CoP of 3.2 to match the energy cost of a 95% efficient natural gas furnace, or 3.1 to match the CO2 output. Hmm. Natural gas is good stuff.