1 kwh, what is it?

[jmarc3]

It doesn't matter whether the pump is electric or pedal operated!

Indirectly according to the use of the kWh in question I think that it matters.

Because if the Kwh in question is used to make exclusively thermal, well the primary energy, also thermal therefore (unless this kWh comes from an Enr source ...), must be taken into account in order to compare 2 quantities of the same energetic nature.

So to "do well" you have to compare:

- electrical kWh and mechanical Kwh (close to generator output near = 0.8 to 0.9)
- Electric thermal kWh and "flame" thermal kWh (factor 2.5 to 3 approximately)

I did not expect to provoke all this debate, very interesting incidentally, with my little kwh
I just wanted to give a pictorial vision of the energy that 1kWh really represents compared to its ridiculous cost (I agree with JM Jancovici).
Once again, knowing how this kwh was produced, how much oil or food for the horse it was necessary to spend, are questions extensively dealt with on the forum where he has more skill than me.

[Remundo]

I see that I do not master the quotes!

code: Select all

[quote="Toto"]
le texte
et tu finis par [/quote]

@+

[Flytox]

It will also require a beautiful pump .... more than 300 m high that makes more than 30 bars at the outlet

[bernardd]

If thermodynamics was simple, it would be known :-)

I went back to the source of your subject.

Your initial example, Jean-Marc, was pretty much right, because you started from a situation, where you had 1KWh electric, and you showed that we had the choice to go to 2 other situations, namely to do a detergent, or to mount water.

The calculation for raising water, on the other hand, was not realistic because it did not take into account the efficiency of the pump.

Remundo's remark, referred to another reaction:

If I extrapolate your values, one km with my electric car is equivalent to mounting 240 liters at 300m in height ...

And mine then to:

there is no confusion but equivalence between all forms of energy (I did not take into account the yields, of course).

We cannot compare 2 situations by referring only to the energy comparison. I don't want to use bad words, but in summary:
2 situations are equivalent if there is a "real" scenario, ie experimentable, to switch from one to the other and from the other to one ...

This is also one of the highlights of your initial scenario: from 1KWh, we can reach the 2 situations "washed laundry" or "water mounted" but the 2 possible situations are not at all equivalent, because we can see although more can be done with "mounted water" than with "washed laundry" ...

... and yet the 2 situations have exactly the same energy, if we make a precise assessment:
- in one case, washing water and machine warmer by 1KW compared to water and machine in the initial state;
- in the other case, water mounted, more heat in the engine, the air around the engine and certainly in some water.

There is therefore no "equivalence between all forms of energy", there can be equivalence of energy without there being equivalence of situations.

And to achieve the same energy situation from different forms of energy, it will take more or less energy depending on the starting energy form ...

That said :

However, this does not detract from the moral of the story of Jean Marc3.

that is, using electricity to heat water is not efficient ...

[jmarc3]

It's true, using electricity to produce heat is an aberration on all levels, physical, economic and ecological.

In fact I do not know why I spoke of laundry, it is irrelevant to the illustration I wanted to make of the low cost of energy, and consequently, of its waste.

[dirk pitt]

I suspect that there are several teachers among the posters because: "hello the fly stuffing"

[Remundo]

Hi Dirk and Bernardd,

And again you will notice that my contributions to the subject were limited to 3 lines. I did not abuse

[bernardd]

I suspect that there are several teachers among the posters because: "hello the fly stuffing"

Missed...

When we want to describe complex problems, we have to speak a little precisely ...

As for the non-reversibility of the real world, this is what prohibits perpetual movement. I very much regret it, but that's how it is :-)

If you prefer pictures:
http://www.savoir-sans-frontieres.com/J ... _votre.htm

http://www.savoir-sans-frontieres.com/

[swift2540]

Nevertheless, the demonstration is clear to me.
Even with a ridiculous yield of 5%, which is ready to mount 1200L of water at 300m in height for 2 €

QED

[bernardd]

Nevertheless, the demonstration is clear to me.
Even with a ridiculous yield of 5%, which is ready to mount 1200L of water at 300m in height for 2 €

Especially when you know how the dumping on fossil fuels is obtained:
Confessions of John Perkins, former bearded man of the empire