Any question answered...

I’ve often wondered what the energy savings would be if people brewed their tea at, say 92 or 95c instead of a rolling boil.
.

"Or, as Tom Williams puts it, “As soon as humans can interact with something, we mess it up.” We often boil more water than we need, using more energy than we need. We also do things like leaving the stove or microwave running after the water has already reached a boil."

http://insideenergy.org/2016/02/23/boiling-water-ieq/

I've got a kettle where you pick the temp. Since setting it to a round 90, I can't tell any difference in taste from old kettle at 100.

I'd like to think that the 10 or so 'boils' a day add up in saved leccy.

See this is why filter coffee is better than tea, no need to boil

How much energy does it take to make the filter, assuming it is a single use one? Is loose tea better for the environment than tea bags? Why can't you all just drink tap water like me? You are all addicted to a caffeine fueled ritual that one day will be as unacceptable as smoking in the office and having 3 pints at lunchtime.

Using DevOps for a project instead of Jira, is there a way to make test case tickets appear on the sprint board? Can't seem to find a way... They appear as the 'child' on the ticket, but not on the boards.

Google / Microsoft help don't seem to have the answer...

unacceptable as having 3 pints at lunchtime.

🤔
Since when?

While we’re on the subject of boiling water ...
Anyone have favourable experience of knock off Quookers?
Having used them in the houses of ‘posh’ clients, I’ve desired one for years, but I can’t afford one.
Marginally more efficient than a kettle (especially in my house where it gets used all the time).
But really it’s all about the convenience- isn’t everything?

having 3 pints at lunchtime.

Thought that was still a popular rich suit lunch

From what I’ve seen they seem to prefer spirits, unless it’s a casual meal.

Not finding much direct comparisons in a quick search, anyone here have opinions/facts about the environmental impact of titanium vs aluminum mining and processing? Basically I'm just trying to decide between an anodized alu kettle and and a titanium one. I know the right answer is steel, but humour me.

@withered_preacher I can answer this. I just needed to check my figures before replying.

Titanium alloy e.g. Ti64

Primary production:
Embodied energy 600-740 MJ/kg
CO2 footprint 38-44 kg/kg

Processing:
Embodied energy 5-6 MJ/kg
CO2 footprint 0.3-0.5 kg/kg

Recycled material:
Embodied energy 228-281 MJ/kg
CO2 footprint 14.4-16.7 kg/kg

Aluminium alloy (typical)

Primary production:
Embodied energy 200-240 MJ/kg
CO2 footprint 11-13 kg/kg

Processing:
Embodied energy 2.5-3 MJ/kg
CO2 footprint 0.15-0.25 kg/kg

Recycled material:
Embodied energy 18-21 MJ/kg
CO2 footprint 1.1-1.2 kg/kg

Figures are from Materials and the Environment (2009) by Michael F. Ashby.

About the ores. As with aluminium ore, titanium ore is fairly abundant and mined in quite large quantities as titanium dioxide. Most of it is used as white paint pigment. Most of the remainder goes to the aerospace industry as titanium alloys. It doesn't come from any dubious parts of the world, so I don't think there are any social issues relating to its mining and extraction (e.g. crime, forced labour, child labour etc). It is very energy-intensive to process into metal - this is where the high embodied energy and high CO2 figures come from, and therefore the high cost. It is also very energy-intensive to recycle, despite the fact that the bulk of titanium is actually recycled from the huge amounts of waste from aerospace machining.

Aluminium is quite energy-intensive to produce as a virgin material (compared to other normal material like steel and glass), but takes very little energy to recycle (around 10% compared to primary production). A very high proportion of aluminium is recycled unless the application specifically requires very pure aluminium for its mechanical properties (e.g. car bodies, drinks cans).

So depending how much recycled material is in there, consider it's going to be at least 3x more energy intensive and 3x higher in terms of CO2. Your decision may be a functional one - will the titanium kettle far outlast the aluminium one? Will you value it more and look after it to ensure it lasts? How many aluminium kettles will you end up using in the same lifetime?

As Tester mentioned, the bulk of the environmental impact in its lifetime is going to be in the heating of the water for drinks.

Energy used heating or boiling water in a kettle. Assuming no losses. There actually isn't really anywhere for the energy to go in a kettle other than into the water, it's quite efficient.

Specific heat capacity of water: 4200 J/kg/K

Lets's say tap water comes out at 15°C. 1 litre water in kettle = 1kg water.

Heat to 92°C = 323.4 kJ = 0.0898 kWh = 1.52p @16.9p / kWh
Heat to 100°C = 357 kJ = 0.0992 kWh = 1.68p @16.9p / kWh

Really not much in it. More of your waste is in the water you heat up and don't use.

I don't know how much you boil off in the few seconds before it shuts off when it's boiling, but it's not going to be much. Latent heat of evaporation of water: 2250 kJ/kg if you want to weigh it. Or 3 kW kettle for however many seconds (best guess).

Heat to 92°C = 323.4 kJ = 0.0898 kWh = 1.52p @16.9p / kWh

Heat to 100°C = 357 kJ = 0.0992 kWh = 1.68p @16.9p / kWh

From UK Tea Assoc. https://www.tea.co.uk/tea-faqs

HOW MANY OF CUPS OF TEA DO THE BRITISH DRINK EACH DAY? A: Approximately 100 million cups daily, which is almost 36 billion per year [Source: ITC].

1 cup = 0.24 L
100 million cups = 24 million L = 24 mill kg H2O

Heat 24 million Kg to 92°C = 24 mill * 323.4 kJ = 7,761,600,000 kJ per day

Heat 24 million Kg to 100°C = 24 mill * 357 kJ = 8,568,000,000 kJ per day

Difference would be 806,400,000 kJ = 806.4 GJ saved every day by making tea slightly differently while minimally/not affecting the end product. (Someone review my working pls).

224,000 kWh per day. Quite a lot when you put it that way.

UK emissions factor is [allegedly] ~0.254 kg CO2 per kWh, so that's 56,896 kg CO2 per day.

Fantastic, thanks for all the research!
Hard Anodized Aluminum and Titanium were neck and neck due to their quick heating abilities due to ultra thin materials, last night though, I ended up ordering a stainless kettle… partly aesthetic, partly durability.

ISO 3103-1980 says the water [edit: for making tea] must be “freshly boiling”.

2 Attachments

That ISO isn't how to make a nice to drink cup of tea, just a consistent one to compare different teas.

Although for green and white teas you are supposed to boil the water then let it cool back down to a lower temperature before steeping.

Black tea is full on at 100°, fuck the haters.

You lot have entirely lost any marbles you once had. It ain't tea unless properly stewed, with a minimum of three sugars. If a spoon won't stand up in it it's namby pamby hipster pisswater.

I withdraw my 'ColinTheBald is slacking' post in the other thread - this confirms you're a legit builder.

Have to respect the accuracy of their wording. Freshly boiled = set to boil recently, so if you left it too long on the stovetop you’d need to chuck it out. Freshly boiling = boiling recently, regardless of when it started.

If I were to venture a guess, using boiling water to make tea started because we can easily see when water is at or near 100C. Thankfully, we can now easily acquire reliable means of measuring the temperature of our water. Insisting on boiling water is just a force of habit that has become an unnecessary, eco-destructive cultural and industrial norm.

#92isenough

we can easily see when water is at or near 100C.

check your sea-level dwelling privilege

^ Recipient of today's Science badge.

The difference is more than you might think - it's about 99.2 C at London's highest point, on the North Downs above Westerham, slightly south of that odd Shampan at the Spinning Wheel restaurant. Which is just higher than the Shard's observation deck.

Edit: At officially 245 m it's almost exactly the same height as the Shard's observation deck at 244m.

I did, hence “near” ;).