OT: The proposed pumped storage scheme at Coire Glas

[Ian Jackson]

I bet that caused a fair bit of global warming!

[alan_m]

The three stage burn is approximately 11 minutes, but the first stage with the lift engines are discarded at around 2.5 minutes.

[Andy Burns]

The SpaceX Starship has about 1/3 the propellant of a SaturnV, and they're hoping to launch three per day to fly stuff to Mars.

Do Tesla's reductions make up for SpaceX's increases?

[The Natural Philosopher]

It still does. BUT it cant be used very often on account of low water levels.

Interestingly people in the USA are stupid enough to believe that water that is used to generate electricity cannot then be used for irrigation.

[The Natural Philosopher]

Why would it?

It's just adding water to a saturated atmosphere. It will just rain.

[GB]

Bit of a generalisation there! All people? Some people?

Besides that, I have no idea whether there's any conflict between optimising for power generation or irrigation?

>

[GB]

Ahem, they used kerosene as fuel, so not just water.

[The Natural Philosopher]

So you are one of them too!

[The Natural Philosopher]

Oh, so they did. I was thinking of the apollo missions with liquid hydrogen.

Anyway we all know that CO2 at current levels has almost no impact on the climate anyway.

[GB]

Am I? Suppose the need for electricity is in winter, so then they would need to release the dammed water during the winter, when there's no need for irrigation.

They have a lot of air con, so peak demand for electricity may, in fact, be in the summer.

That's why I said that I have no idea whether there's a conflict. Do try to keep up.

[The Natural Philosopher]

And where dies that 'released' water go, in the case of the colorado river? To the irrigation dams further downstream

Do keep up

[GB]

So, what you are saying is that optimisation is not a problem. At least, only when the downstream dams are full. Which I gather is rarely.

If only the rest of us were as clever as you...

[Tim+]

Well there is if the water for irrigation is being extracted upstream of the dam.

Tim

[Paul]

Of the fuels currently being bandied about, one concern is CO2, the other concern is "soot particles at high altitudes".

There might be regulations some day, pushing for hydrolox.

There is kerolox and methalox. Some are better for reusable engines than others (you can soot up an engine too).

"Unlike some other fuels, methalox does not "coke" the engines - so it is a good choice for reusable engines. "

Yesterday, a methalox tried to reach orbit, but didn't succeed. Main engines were fine, second stage didn't light properly.

Paul

[The Natural Philosopher]

Oh, the ones produced by volcanoes, forest fires, and the constant rain of micrometeorites? That are naff all to do with humans?

Well best abandon space flight altogether and cower in your safe space.

[Davey]

My thermodynamics lecturer preferred the furlong-firkin-fortnight system of units.

[Andy Burns]

I finally got bored enough to work it out ...

taking an average elephant as 4500 kg the area of wales as 20779 m^2 and a cubic fortnight as 1209600 s^3

one elephant wales per cubic fortnight is 77.30 watts so a Saturn V is 1.55 giga elephant wales per cubic fortnight

[Chris Hogg]

at

[Andy Burns]

grrr try km^2 instead of m^2

77.3 MW

1.55 kew/f^3

[Chris Hogg]

Have you done a dimensional analysis on that? :-)