Time to get rid of a gas hob?

silverwhistle

I've an induction hob wired on a cooker circuit so no restraint issues, but remember there is an on/off cycle so a bit of diversity when you are using multiple rings. At this time of year it's nice to have the heat in the pan and not in the atmosphere.

As for cost, mine came from a well known Swedish retailer, from the cheaper end of their range and not at all expensive. I have gas in the house but I wouldn't go back to it, so my tenants who managed to get the gas hob condemned rather did me a favour.

wittynamegoeshere

There's probably little or nothing in it, extremely unlikely to be enough to justify the cost of a new one.  There may be much bigger gains from cooking more efficiently.

I'm ashamed to say I'm a fairly recent convert to putting lids on pans.  Whatever the heat source, they boil faster and keep simmering on lower heat.

The other possibly bigger advantage is that the steam/damp is reduced massively.

Also recently started boiling rice in just enough water (2x by weight) until gently boiling it dry on the lowest setting, which saves energy and tastes nicer too, especially if you throw in a few veggies and/or spices.  This is exactly what a rice cooker does, but it's easy with a pan and lid.  I always used to boil rice in surplus water then drain, followed by a kettle of boiling water to rinse the excess starch off.  Now I rinse the uncooked rice in a sieve in cold water before cooking.

But, to echo the silly kettle thread recently, a sandwich or a salad would cost less than gas or electric!

Alnat1

With the rice, cook for 10 minutes with a lid on then leave. It will soak up any remaining water, stay warm for another 10 minutes or so and no chance of it sticking/burning.

wittynamegoeshere

Alnat1 said:

With the rice, cook for 10 minutes with a lid on then leave. It will soak up any remaining water, stay warm for another 10 minutes or so and no chance of it sticking/burning.

I have a knack, rice and cold water in pan, full power, stir once when boiled then heat down to 2, then 1, then off when there's just a coating of water left in the bottom.  The remaining heat in the hob takes care of it.  All of this takes much less than 10 mins, more like 5.  If you cooked for 10 mins you'd probably have a kitchen full of smoke.

Sandtree

Cardew said:
and I suspect there is little difference in the running costs.

It may be what you suspect but no way near the truth yet... gas hobs are generally circa 40% efficient whereas induction whereas induction are around 90% efficient. So until electricity is only twice the price of gas then they will remain cheaper to use. 

Running I'd include maintenance in and I am certain it'll cost a lot more to fix an induction hob where one "burner/ring" has died than almost any gas stove. 

We recently went from a dual fuel cooker to a 7.5kW induction hob (we'd "replaced" the ovens, so to speak, some time before) and love it but there was no cost saving involved (and ended up more expensive than anticipated as old pans that claim to be induction compatible weren't) 

wittynamegoeshere

Sandtree said:

Cardew said:
and I suspect there is little difference in the running costs.

It may be what you suspect but no way near the truth yet... gas hobs are generally circa 40% efficient whereas induction whereas induction are around 90% efficient. So until electricity is only twice the price of gas then they will remain cheaper to use. 

Where are these figures from?

There are way too many variables to make sweeping statements.  Much of the heat loss comes from the pan itself, not the hob.  However efficiently you heat the pan, lots of it just radiates and convects into the air.  So unless you have lagged pans I doubt you're going to see the sort of difference you're suggesting.

I'm saying it's more likely that gas remains cheaper, which is what I think you're suggesting anyway.  But I'd be suspicious of such round sounding numbers.

I doubt that most people use more than a tiny fraction of their energy for a hob anyway, it's probably lost in the noise in comparison to heating hot water or a house, so any marginal differences between alternatives must be even smaller.  Someone I know had gas solely for a hob, and their supplier kept checking the meter as they didn't believe that anyone's usage could be as low as it was.

Sandtree

wittynamegoeshere said:

Sandtree said:

Cardew said:
and I suspect there is little difference in the running costs.

It may be what you suspect but no way near the truth yet... gas hobs are generally circa 40% efficient whereas induction whereas induction are around 90% efficient. So until electricity is only twice the price of gas then they will remain cheaper to use. 

Where are these figures from?

There are way too many variables to make sweeping statements.  Much of the heat loss comes from the pan itself, not the hob.  However efficiently you heat the pan, lots of it just radiates and convects into the air.  So unless you have lagged pans I doubt you're going to see the sort of difference you're suggesting.

I'm saying it's more likely that gas remains cheaper, which is what I think you're suggesting anyway.  But I'd be suspicious of such round sounding numbers.

I doubt that most people use more than a tiny fraction of their energy for a hob anyway, it's probably lost in the noise in comparison to heating hot water or a house, so any marginal differences between alternatives must be even smaller.  Someone I know had gas solely for a hob, and their supplier kept checking the meter as they didn't believe that anyone's usage could be as low as it was.

Much heat loss in gas comes from the heat from the flame going up the side of the pan and out into the ether... put a large/heavy cast iron pan on a gas burner and put your hand to the side and you'll feel the lost heat. 

The numbers will be round because they are going to be an average rather than a definitive figure that each and every hob applies to. The biggest difference with gas hobs is making sure your pan isn't too small for the hob ring size else the lost heat up the sides is significantly worse. The 40% and (up to) 90% is used fairly widely online but for example comes from this paper https://www.aceee.org/files/proceedings/2014/data/papers/9-702.pdf 

QrizB

wittynamegoeshere said:

Sandtree said:

Cardew said:
and I suspect there is little difference in the running costs.

It may be what you suspect but no way near the truth yet... gas hobs are generally circa 40% efficient whereas induction whereas induction are around 90% efficient. So until electricity is only twice the price of gas then they will remain cheaper to use. 

Where are these figures from?

There aren't Sandtree's figures, but Technology Connections did a video on this.

https://www.youtube.com/watch?v=_yMMTVVJI4c

Jump to about 13m for boiling a kettle on a small gas ring (26.6% efficient)

And to 14m40s for the same kettle on a larger ring (24.7% efficient)

To 16m for a ceramic hob (46.5% efficient)
To 18m50s for the kettle on an induction hob (69% efficient - not calculated in the video but 1800W for 269 sec is 134.5Wh).

wittynamegoeshere

Technology Connection's videos are interesting entertainment but definitely not rigorous science!

So are we all agreeing that cooking with gas is likely to be the cheapest option?

But I'd suggest that the amounts either way are going to be pretty trivial for typical use.

My smart meter doesn't budge much as a result of my typical cooking, and that's with a ceramic electric hob, possibly the most expensive method.  But even so, I doubt I'd ever recover the cost of a new induction hob.  We'll get one, but it will be in several years and part of a refit that's going to happen anyway.

QrizB

wittynamegoeshere said:

So are we all agreeing that cooking with gas is likely to be the cheapest option?

But I'd suggest that the amounts either way are going to be pretty trivial for typical use.

Most of my stovetop cooking involves boiling water (or something that's mostly water) then holding a simmer for a period. so yes, I'd agree with both those points.

Assuming gas at 7.5p/kWh and electricity at 28p/kWh, supplying 93Wh to boil a litre of water per TC's examples:

• Small gas ring - 356Wh, 2.67p
  
• Large gas ring - 376Wh, 2.82p
  
• Electric kettle - 108.4Wh, 3.04p
• Induction hob - 134.5Wh, 3.77p
• Ceramic hob - 200Wh, 5.6p
  

"Pretty trivial for typical use" seems a fair description.