Some smells never leave your primal gut memory. For me one of those is the vaguely sulfurous scent of natural gas in 1920s-vintage buildings that are relatively close to the water in Great Lakes cities like Toronto, Cleveland, and Chicago. I remember visiting as a youngster my paternal grandparents’ home in old Scarborough (now part of amalgamated Toronto). My grandmother was an awesome cook; one of her many specialties was turning the leftover Christmas goose and turkey into delicious soup. She used to show me how it is properly done, and always praised the magical properties of natural gas as a cooking fuel. She used to say “it makes the whole house smell wonderful.” Years later I stepped into a 1920s apartment block in Cleveland Heights, and caught the exact same scent. Same during a 1995 visit to Chicago, when I ducked into the lobby of a really interesting downtown building (to the huge annoyance of my then-girlfriend, who was impatient to get to a restaurant on time). Both times the scent instantly brought me right back to Christmases at my grandparents.
Pretty, but polluting. Why not just use electricity, which is cleaner and safer? When you cook with natural gas, you produce far more CO2—and carbon monoxide (a deadly poison), and nitrogen oxides (bona fide air pollutants)—than you do when you cook with clean electricity. And that pollution goes directly into your indoor air; electricity brings zero pollution into your home. In Ontario, at the time of writing, gas-fired cooking was six times as dirty as grid electricity.
But in my adult life I have never used gas as a home cooking fuel. I have never liked the idea of having an open flame in my home (this aversion does not apply at my hibernacle, which is wood heated). I scoff at the notion that there is any difference between food cooked with electric or gas-fired heat, or in the experience of cooking with electric versus gas.
And now that I know a thing or two about electricity and air pollution, I am even more firmly in the electricity camp. The phrase “cooking with gas” has a double meaning. When you are cooking with gas you are using gas—essentially methane (CH4)—as fuel for heat, and in the process you are producing another gas—essentially carbon dioxide (CO2)—as a byproduct of that heat.
How much CO2 do you produce when you cook with gas? According to the California Energy Commission, if you run a gas oven for one hour at 350, you would use 0.112 therms of natural gas. (A therm is 100,000 Btu, or 97.75 cubic feet, or 2.77 cubic meters, of gas.)
The U.S. EPA says that one therm of combusted natural gas produces 5,306 grams (one metric ton is 1,000,000 grams). Environment Canada gives a similar number: 1,879 grams CO2 per cubic meter, which when you convert m3 to therms gives 5,320 grams (one therm = 102.3 cubic feet, and one cubic meter = 35.3147 cubic feet—sorry for these mind-numbing unit conversions, but blame the U.S. for not going metric.)
ANYWAY—going back to the gas oven running at 350 for one hour: the California Energy Commission says it will use 0.112 therms of natural gas. So 0.112 therms (2.77 m3 times 0.112) of natural gas will, when burned, produce 582.9 grams of CO2. That is more than half a kilogram.
The same California Energy site says that an electric oven would use 2 kWh of electricity to do the same job.
Well, if that electric oven were connected to the Ontario electricity grid, it would, at one-thirty p.m. on Friday May 24 2013 use electricity that comes with 48 grams of CO2. That means 2 kWh, each with a CIPK of 48 grams, would have produced 96 grams of CO2. See the bottom row of Table 1 on the left-hand sidebar for an up-to-date CIPK (CO2 intensity per kilowatt-hour) figure. Multiply that figure by 2 to get the amount of CO2 that goes with running an electric oven at 350 for one hour; is the result more or less than 582.9?
So in the comparison of the environmental impact between gas and electric ovens, there really is no comparison. Electric, at one-thirty this afternoon, was more than 6 times as clean.
This means that, instead of making electricity expensive as a way of lowering CO2 emissions by forcing consumers to cut electricity use, we should make electricity cheap and encourage people to switch from gas-powered to electric-powered appliances. Right now, there are people being uncommonly scrupulous about unplugging the TV or computer at night, and then undoing any small benefit by using gas appliances.
How could we make electricity cheap? By dumping the Ontario FIT program which forces ratepayers to pay high prices for inefficient wind and solar power, and using more cheap, zero-carbon nuclear.
That does assume that the evening dinner-hour demand spike would be served with nuclear power, and not something gas-fired.
It’s worth noting that “gas” wasn’t always natural gas; at first, it was “town gas” made from coal in a “gas works”. This synthetic gas was composed of hydrogen, carbon monoxide, and other constituents (including nitrogen if the gasifiers were air-blown). The high fraction of CO is why “gas ovens” were once a preferred method of suicide.
Things are different now, so why not different in the future? Maybe a low-carbon gas made mostly of H2 with some CH4 and synthesized from organic waste could be the storable peaking/cooking fuel of the future.
Re: “Things are different now, so why not different in the future? Maybe a low-carbon gas made mostly of H2 with some CH4 and synthesized from organic waste could be the storable peaking/cooking fuel of the future.”
That’s intriguing! There’s going to be that segment weaned on gas as the “true” cooking heat for a while (like the vinyl record vs CD argument), so maybe as long as we have a gas infrastructure there might be less carbon-contributing gases/liquid fuels than natural gas to accomodate them till? I don’t know but maybe some kind of alcohol based thing? V-2’s were propelled basically on potato juice if I recall and when they crashed in testing their explosions and flames were remarkably quick and sootless and “blackless”. Just a notion.
James Greenidge
Queens NY
Since natural gas wells are necessarily also radon wells, I did a quick Google of (kitchen gas radon) and found, surprisingly, a non-nuclear-exceptionalist article from NIRS on this:
According to Rosalie Bertell in her book “No Immediate Danger” on pages 87 and 88:
“This ‘technologically enhanced natural background radiation’ (TENR) now ranks first as a source of individual internal radiation exposures in the USA, ahead of medical and radiopharmaceutical exposures. It ranks a close third, after medical and radio-pharmaceutical exposures, as a source of general population dose.
This TENR ranking is due primarily to the lung dose from inhalation of radon dissolved in natural gas and trapped in well insulated homes.”
you have a conversion error – one cubic meter of natural gas yields 36kbtu. 0.112 therms is equivalent to 0.27 cubic meters so your co2 numbers are 10x actual.
which means electric produces more CO2 than gas!!!
thanks, and sorry for the torture of crawling through those numbers. Why oh why did I get into therms in the first place.
Why didn’t I just compare 2 kWh of electric with 2 kWh of gas… gas CIPK is 188 grams, electric anywhere from 5 to over 100 (like yesterday).
So that’s a minimum of 376 grams for gas, maximum 200 grams (and usually much much less) for electric.
Ontario electric does NOT produce more CO2 than gas. It might when Pickering goes offline, if we don’t replace it.
I think the original meaning of ‘cooking with gas’ was to advertise the ease of gas stoves over coal or wood. I think there should be a similar push to get everyone to move to induction, in the places that have invested in hydro.
Out west on the prairies, heat and cooking were done with coal, because there wasn’t a meaningful amount of wood. The power grid was set up to use coal, because there wasn’t a lot of flowing water, and is now switching to natural gas, because there is a LOT of that.
Using an electric stove is going to be ‘dirtier’ in Alberta, because turning on electric heat is going most likely to ramp up the fire on a coal or natural gas power plant somewhere.
The exceptions are those rare times when there’s additional wind, hydro, or even solar power available, and it’s curtailed because there’s too much supply or not enough transmission capacity. (By ‘rare’, I mean it probably hasn’t happened intentionally, and if it has, probably not for more than a few minutes.) But as the author says, fewer actual fires inside home appliances is probably better for reasons that have nothing to do with climate change.