Cooking with gas - health and environmental concerns

MythDefied Is it true?
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Is cooking with gas a decision any of us should be critical of?

Whether there is growing concern? Approximately 5 million Australian homes are connected to reticulated gas and another 2 million have LPG. (Industry assessment). Other sources suggest this growth has slowed.

In context, is the total amount of reticulated natural gas or bottled LPG consumed by a gas cooktop significant when compared to?

  • the volumes of these gases consumed for other household purposes,
  • the quantities of fuel consumed by our motor vehicles,
  • or the fossil fuels used in electric power generation.

Is there a need to be most concerned about the more significant environmental Green House Gas emissions and the combustion byproducts that affect the health of every one?

For a new build making an informed decision about cooking and energy is important. There are options that can be considered and costed. Gas excluded, there are numerous options/scope to suit our varying needs or preferences.

For those in an established home cooking with gas, there are many other decisions that could be made to deliver a better return for our dollar. Judged on the very small impact on the environment relative to likely outlay.
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In particular:

1/ What are the health concerns to gas cooktops, and are they riskier than other set-ups?

This has had a long community discussion previously.

There are health implications from burning any substance or using any chemical (air scents, insect sprays, paint) in the home. Cloths fluff/lint, mould, dead hair and skin particles are some of the most common contaminants in homes. Particulates from car exhausts and vehicle road contact are another.

With a gas cooktop a properly installed exhaust hood can manage any residual risk. The others most of us accept and live with every day.
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2/ What are the environmental concerns, and what are the alternatives?

The average household in Australia contributes 7 tonnes of CO2e to Australia’s annual GHG emissions (70 Mt of a total of 540 Mt annually). Of that 7 tonnes approx 75% is due to emissions from fossil fuels used to produce electricity.

We have a gas cooktop, and bottled LPG now. Also in our previous home. Experience with a small family a gas cooktop will consume as little as 10-15 kg annually. Our current 2+ person home consumes 100-120kg pa LPG for all HW, Oven and Cooktop. (0.16 - 0.19 t pa CO2e)

The average passenger vehicle in Australia emits 165 g/km CO2e, or for the annual average of 12,000 km, 1.98 t pa. Note many households have 2 motor vehicles.

A typical Aussie home consuming 6000kWh of electricity from the grid causes 5.4t of emissions annually (at 900 kg/MW CO2e).

Gas consumption in a home, heating excluded is not significant compared to other energy sources, or compared to other, dirty sources of environmental emissions.
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3/ Are there any other pros or cons to gas cooktops that should factor into the discussion?

Cooking is very much about individual preferences. The choice of cooking styles, ingredients and utensils differ. Are we at a point where one half of the nation should be influencing the other half on what type of cooktop to use? Is it critical to the future of the nation?

I can only suggest that the backyard fire pit, or outdoor BBQ, pole type gas heaters, and wood fired pizza ovens all offer similar levels of environmental and health risks. A properly designed and ventilated gas cooktop, and oven optional, are safer and more efficient.

In asking about gas cooktops, we need to expand the question to include all of the above, or defend our hypocrisy. Choice might need to discontinue recommending a certain BBQ product and only review electric. Hopefully a well considered option. Irrespective of how pathetic a product they might be?
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For the Future?
There are many alternative sources of gas fuels that can be provided from carbon neutral sources, and or green energy.

I’m not convinced that the future of the great Aussie BBQ or Chefs kitchen is all electric. Perhaps Tesla will add a drop down electric grill to the Cyber Truck to prove me misguided?

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There are far more impacts associated with any cooking method than GHGs. One needs to consider the impacts of each method, including from cradle to grave and its operation, when making a decision. Basing a decision on one factor may not provide, in balance, the best environmental outcome nor the best cooking solution for an individual.

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23

I’ve decided many times to get rid of my freestanding gas stove. It doesnt have an electric connection and to change to electric is prohibitive. I have a friend who was a cabinet maker before he became a nurse and I’m hoping to get him to build me a cupboard to fit the space the gas stove will leave behind when the plumber comes to remove and dispose of it. I will not miss it one iota. I’ve been in this house for 20 years and I’ve hated the gas from day one. Should have moved on it much sooner. I’m going to get either a double or two single portable induction cooktops, and will use the microwave oven for grilling and baking.

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I may be mistaken, but I was under the impression that the metal in the pot/pan on the cooktop heats, and therefore food anywhere in contact with the surface of the metal would cook.

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That is quite correct but not all of the metal gets hot in this case. The heating is due to cycles of magnetism going through the metal and the range of the magnetic force is quite limited. You can show this when you test a pot or pan with a small permanent magnet. If the magnet sticks to it the pot is suitable for an induction stove but if you lift the magnet away you will find that the force of attraction drops dramatically with distance, in a few mm it has almost no effect on the pot.

It is the same with the stove, its magnetic field is only good for a few mm so all the curved surface of a standard wok is quickly getting further away except a little circle in the middle that is touching or close. You would have only a fraction of the wok being heated so it doesn’t work very well despite being all iron.

For a wok to do its job the whole thing must be heated, so gas wok burners have double and triple rings of gas flame and burn gas at a high rate, in this case the way gas burns is a positive as the very hot air above the flame also heats the metal. An induction wok burner must be curved to the same shape as the wok to be able to transfer heat all the way round, a flat induction plate and curved wok don’t fit and are very inefficient.

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I find it efficient enough to work well for my cooking, and when the wok is powered renewable energy it is much more environmentally sound than burning gas. It only requires the lower heat settings, so uses very little energy. In any case, if you needed more heat, a flat bottomed wok is much less expensive than a curved induction hotplate.

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I agree with all you have said. I don’t doubt that for your needs the system is adequate. I am not saying you are wrong but that we are different.

For those who want the benefits of the induction method that you list and also those of traditional wok cooking the curved wok on the flat plate doesn’t work for reasons detailed above, it just doesn’t get hot enough.

A flat bottomed high-sided frying pan (which is not a wok) is not good enough either as most domestic induction stoves don’t have the power to get it hot enough.

I have used a stove with the standard 3kw on the biggest and nothing works well. I have also used a 5kw, which was just workable but had a second problem. The geometry of the flat bottomed pan is wrong for the very quick tossing required at very high heat. I could get adequate results for a small amount of food by adapting my technique.

Our disagreement comes down to what you will accept as being satisfactory wok cooking.

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I don’t understand that, even on low, (on/off cycling but probably averaging < a few hundred watts), mine will smoke oil within ~15 seconds. It is a mild steel wok.

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It’s the difference between heat and temperature. In a small area you have smoking hot oil, I want it all over, say we mean 210 C for argument’s sake. One takes a few hundred watts the other a few kilowatts.

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I’m of the same experience as @syncretic. The side burner on the gas BBQ is the only place I can get enough heat into a wok to cook as intended. The alternative is everything tends to stews, while the veges all come out limp/wilted. Anyone who has had an electric wok will have shared that experience. Although you only need to toss the electric wok once - to recycling?

Cooking in a wok is a great way to get great tasting food with minimal oils and fats, without destroying as many of the nutrients.

I’d suggest the real point being made is the designers of induction cooking appliances have neglected to design a wok shaped induction coil, with matching pressed or spun iron wok. It can’t be that difficult. It may be niche hence expensive.

P.S.
For as long as Weber, BBQ’s Galore and others continue to promote gas BBQ’s, I’ll happily continue to cook on gas, wok included in our current home. If I were to build a new home it would be all electric. Although I’m not sure I could live without a gas BBQ, and the side burner for the wok.

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They exist. And they are very expensive.

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As an increasing amount of homes are now using efficient electric reverse cycle aircons for their heating rather than a less efficient ducted gas heater, as well as the efficient electric heat pumps for their hot water rather than a less efficient gas hot water heater, having gas supplied to your house just for a cook top will cost you about $300 per year just for the suppliers fixed daily charge. And, of course, there will be additional charges for the gas consumption as well. Adding PV panels makes the electricity option even more appealing.

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33

Not at our place.

We have the same setup at our current home that we had installed at our previous residence which consists of 2 x 9kg LPG bottles and a changeover switch to feed the cooktop.

We get up to 11 months from a bottle and it costs us less than $30 per annum for gas and no rental charges.

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34

@gordon made a similar observation. Reticulated gas is a expensive, especially if it’s just for a cooktop.

Two homes past we had a similar set up to @Fred123 with a bottle of LPG for the cooktop. Same sized 9kg bottle for the BBQ. The BBQ bottle did not last as long as the one for the cooktop. If one chooses to cook on gas it’s not an expensive option. The GHG emissions are very small, while the future includes options for zero carbon (no guilt gas). Although it may cost a little more per bottle.

Great points about RC Air Conditioning and HW systems. Is the best performing option in some areas ground sourced heat pumps as the alternative to high capacity low cost gas heating. Solar HW with off peak or boost might be my preferred alternative to a heat pump HW system. Worthy of a seperate discussion as to the costs in a new build vs the cost to convert.

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Individually yes, but when you consider the hundreds of millions of people doing it, the emissions are huge!

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Not to mention the GHG losses during production.

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I’m assuming that includes the other cooktop - gas powered BBQ? :wink:

Just an observation that huge to me is those 1.5 billion vehicles consuming around 1500 litres of fuel each annually.

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38

I love my induction cooktop. After swearing by gas for decades l have found the new generation induction to be superior. Gas flames are dangerous and have burnt saucepan handles - toxic fumes, and flames from fat spats are scary.

The only reason I kept gas connected to my home was for the cooktop despite the outrageously high ‘connection’ fee which was always more than my consumption fee. When I stayed with a friend with induction l was won over. Now proudly fossil fuel free and safer in my home.

Smug Wendy adds:

Re wok cooking - try cooking smaller amounts of food - will flash fry in flat ‘wok’ and then tossing all together for final flavour through.

Re hot water - electric heat pump hot water with solar panels - almost free :grinning:

Re heating / cooling- pay for more insulation and regulate with windows and heavy drapes.
I use my reverse cycle A/C about a dozen times a year.

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39

The gas supply in Melbourne is a lot more reliable than electricity, (although years ago a catastrophic industrial accident at the Longford gas plant left the city of Melbourne without any gas supply for 2 long weeks).
With electricity, in Melbourne there are planned and unplanned outages, there’s a website to check the affected areas, at the moment (6pm) Dockland is under investigation.
It’s not unusual during heat waves to have blackouts due to too much demand.
It makes sense not to rely on just one source of energy and thus avoid a lot of inconvenience.

The supply charge for gas is between
70 and 90 cents a day.
For electricity it’s 80 to 1.20 a day.
(Combined cost much less than a cup of coffee).

In my case, there’s centralised gas hot water in the apartment block, which would charge for supply anyway.
And the confined space of my kitchen in the flat is not the ideal place for a gas bottle.
There’s been enough reports of accidents in apartments nearby.

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I live in Darwin and I use Gas for one main reason. If a Cyclone hits, then there is no electricity. Gas (Gas Bottles ) are also portable so if half the house is destroyed,
relocating the kitchen is relatively easy. I also have a Gas fridge.
BTW, because of our warner climate,
many of us have our kitchens outside. That’s not just because it’s environmentally nice to sit outside, but because cooking generates a lot of heat. Cooking outside keeps the heat and smell out of the house. Of course I could do that with an electric hot plate I suppose.
A lesser factor is cost. Gas, costs me about A$66 a year and I don’t have to worry about power-outages during cooking ! The cost of my Gas stove (full electric start) was only A$32 ! I brought it back from Indonesia after a weekend trip there. 6 years later, it’s sill going fine, although important to turn-off the gas at the gas bottle after use.
The drawbacks include, the limited life of the Gas Bottle (and the cost of replacement) and having to waste 40 minutes 3 times a year, to go fill the Gas bottle. The old (expired) Gas bottles make fantastic BBQs if you cut them in half. As for environmental concerns… well… I think our City electricity is produced from gas turbines so I suspect using Gas to produce electricity just to run an electric stove, may not be as efficient as just using Gas directly. I suppose the argument could be, I should be using photovoltaic cells on the roof to power my electric stove (limiting my cooking to sunshine hours?), but I built my house in 1986 and made a decision to make extensive use of vegetation to shade the house/roof. I don’t need Air conditioning (most of the time).
Anyway, I rather think that we (in Darwin) should be focusing on how the City power is being generated and establishing environmentally sound ways of storing power. Batteries ARE NOT environmentally sound. Unfortunately, COVID has not just made us all sick, it’s made many of us stupid as well. The big show-stopper at the moment is in environmentally-sound & cost-effective power storage technologies and their effective deployment.

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