Is cycling anywhere near as green as it could be ?

[steve292]

So in terms of energy expensiture, that 15,000 Wh to create 1Kg of alumiunium is equivalent to 22,000 miles of car travel. So the energy required to manufacture a 2Kg frame would power a car for 44,000 miles, and thats to just for the basic raw material, never mind drawing into tubes, hydroforming, welding, etc.

But how much energy did you use to extract the materials for the car? You are conflating the two statistics of running costs and manufacturing.
There is around 200-250kgs of aluminuim in a modern car. You do the maths. Plus you are out by miles on the energy contained in petrol.

 

[Punkawallah]

How far back along the chain do you want to go? Are we taking into account the manufacture of the machines to extract the materials? The energy used to produce the people to run the machines?

Only asking to aggravate :-)

 

[mudsticks]

How far back along the chain do you want to go? Are we taking into account the manufacture of the machines to extract the materials? The energy used to produce the people to run the machines?

Only asking to aggravate :-)

I think we've already established we're taking into account the embodied energy in any devices used.

And the energy used to run the factories too.

Cheap but dirty energy, and cheap but dirty labor practices are one of the reasons why so much manufacturing is outsourced to countries with less regulation on such matters.



Whereas energy used to produce the people to run the machines.??

Hmm, they don't call childbirth 'labour' for nothing .

 

[DCBassman]

That oft quoted tidbit is tosh.

A typical, workaday, moderaltely lightweight bicycle frame weighs 2kg. 2kg of aluminium requires 15,000 Wh of electricity per Kg.

Petrol is 454Wh per gallon.

A typical petrol car will easily achieve 50MPG.

So in terms of energy expensiture, that 15,000 Wh to create 1Kg of alumiunium is equivalent to 22,000 miles of car travel. So the energy required to manufacture a 2Kg frame would power a car for 44,000 miles, and thats to just for the basic raw material, never mind drawing into tubes, hydroforming, welding, etc.

44,000 miles equivalent of energy, just to make the raw billet metal required to manufacture a frame.

Chuck in the energy required to manufacturer everything else required to make a bicycle, transport them from elsewhere across the globe to the bike factory, and you're looking at an energy expenditure that would power a car for the thick end of one hundred thusand miles. And thats before the bike has even travelled a single metre with a rider on it.

So when people trot out this stuff about cycling being mpre energy efficient than walking, even when accounting for the energy required in its manufacture, theyre talking out of their behind. The maths don't lie.

Except...you're talking new aluminium. Not a massive amount mined these days, it's mainly recycled. And if it were recycled more efficiently, maybe we wouldn't need to mine any at all...

 

[mudsticks]

Except...you're talking new aluminium. Not a massive amount mined these days, it's mainly recycled. And if it were recycled more efficiently, maybe we wouldn't need to mine any at all...

I'd always understood that aluminium is one of the recycling success stories, and that most of what we've mined is still in circulation.

The internet seems to confirm this.

But as you say we could still do better..

 

[Brooks]

Thanks for that link mudsticks that was a really interesting read and it's good to know that 75 percent of aluminium that's ever been produced is still in use today.

 

[mudsticks]

Thanks for that link mudsticks that was a really interesting read and it's good to know that 75 percent of aluminium that's ever been produced is still in use today.

No worries,

Anything to avoid having to go out to work in the (much needed) rain..

This discussion reminds me of the one that those of us in the agroecological farming world have rather regularly.

We're often dissecting the minutiae of what we do, and how we operate .

Could we adjust ourselves to be 'even greener' work that bit harder to become even more ecologically benign.

We get tied up in knots over recyclable versus biodegradable packaging, and any number of other issues around soil care, ecology, productivity etc etc.

Were generally trying our best though, within the limits of possibility, right now.

But in a world currently set up so as to make nearly everything we're trying to do, to do better, doubly hard.

But if we stick our heads above the parapet, and critique the present state of play.

We immediately get charged with 'hypocrisy' because we're not being whiter than white in every single aspects of our lives.

As if one is only allowed to criticise a system if one is living totally outside of it.

Which is clearly nonsense if you think about it for a nanosecond


As ever there's a lot more, that a lot of people could do..

Perfectionism, being the enemy of 'much better'

Including, most vitally imo voting in governments that do actually give a shoot, about this stuff, and holding them to account .

Oh well , waterproof on >>>>

"No such thing as bad weather --

There's only, being dumb enough to go out in it "