VtoG

[The Natural Philosopher]

yup. easy peasy charge a battery off peak at 2p a unit, feed back into grid with dummy PV at 41p.

Simples!

[The Natural Philosopher]

Ah, but I need abut a Kw for three days..

Bit more than 175 watts, a cigar lighter or a car battery, can manage.

[dennis]

Of course you can use

and see what the true figures are.

[The Natural Philosopher]

Sadly it is for small flywheels and gives numbers you still have to scale when you start talking tons and meters.

And of course, it says nothing about the shape of the flywheel. I.e. whether its concentrated at the rim or uniform across the disc area.

But as an alleged physicist, you would have known that.

Which makes it a bit dumb to have suggested using it.

By the way 50GWh is about the yield of the first atomic bomb.

Which shows you approximately how stupid the whole idea is.

And why a 500 tonne asteroid at escape velocity plus. is not a nice thing to have fall on your head.

[john]

Oh ye of little faith!. Yes indeed, the speeds are staggering and hoop stresses unbelievable but fancy composites, magnetic bearings and vacuum containment are currently giving 100kWH per kg (and more). It's a case of extrapolation and is the basis of our engineering history . That storage capacity is viable. I'd think the more worrying engineering problem is damage limitation in case of catastrophic failure. 1.8x10^14J is near identical to the energy of the first Atomic bomb.

[Dave Plowman (News)]

Given all batteries fail after a number of cycles, and those fitted to cars are extremely expensive, wouldn't it be best to use it just for the purpose intended?

[Dave Plowman (News)]

Organise your life better? Why do you have to shop every day?

That's the rub. Electric cars are expensive to buy. On some the battery is so expensive you pay a monthly rental rather than buying outright. Which can more than negate any savings on fuel costs on a little used vehicle. Of course they've been promising cheap batteries for years...

Why not buy a small cheap secondhand diesel car? Diesels don't wear out in the same way as petrol if used for short journeys.

[Dave Plowman (News)]

And they'll slap on some form of tax to recover the lost revenue from petrol etc sales. If there were no tax on petrol to match electricity there'd be no general interest in electric cars.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "David WE Roberts" saying something like:

Lots of sea inlets in Scotland and Wales.

See

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember The Natural Philosopher saying something like:

Here you go.

you fit too, when the battery goes flat.

[The Natural Philosopher]

That of course is the point.

My experience of lithium to date is that they fail anyway after a few years. Whether used or not.

So there is a converse argument that you might as well do something profitable with them before they die..

Its not clear apart from the obvious - that deep discharge kills them, as does over charge or high rate discharge - what the actual failure mode envelope is.

Without knowing, there isn't a good answer to your question.

And lithium technology is a rapidly moving target.

Every year the packs seem to be better than last years packs.

[The Natural Philosopher]

well arguably they should then tax gas and oil and coal used in power stations instead.

Which would be a huge incentive to build nuclear ones.

[The Natural Philosopher]

But not 1000 feet high, with narrow entrances.

The cost of a wall strong enough to take 1000ft deep water, is immense.

Indeed. Every time I see something that will 'create tens of thousands of jobs' it tells me its essentially impractical and far too costly.

30,000 people on 30,000 annual salary is about a billion annual cost base.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember The Natural Philosopher saying something like:

Only you mentioned 1000'. A few smaller installations work just as well. Still, I can ignore people like you, who would have dismissed the pioneering works of other visionaries of the past. Is it just sour grapes, or is it a deeper malaise?

[dennis]

If you want to store energy why not compress air into old oil wells or mines? There are a lot about that should be able to store a lot of potential energy and some sort of turbine should be adequate to convert the energy to something useful.

[Andy Champ]

I too get 19km/sec. 18973.66596 to be exact.

Andy

[js.b1]

Spain & Africa solar power stations. The historic problem has been "no power at night" which is more a problem about achieving sufficient thermal store. Magnetite will handle over 1000oC and is dirt cheap, so is sand.

PV can only become economic when panels are =A3400 per 1000W. At that point it becomes practical for consumers to purchase like a TV to provide domestic baseline load.

I wonder *just how much money* has been wasted thus far on "green bollocks" from light bulbs to wind mills to garbage research grant trough which instead could have subsidised panels down to that level. We've spent billions on wind farms, why not discount 1000W PV panels down to =A3400 - a neighbourhood of such panels could handle fridge/ freezer startup, kettle, microwave.

Ebay is 240W for =A3700, lets say 1000W would be =A32500. Bulk purchase of 100,000 x 1000W gets it down to =A32000. Subsidy down to =A3400 is just =A31600 for 100,000 units or =A3160M. Subsidy down to =A3400 is say =A31200 for 1,000,000 units of =A31.2B. Lifespan is 25yrs nominal.

How does that cost out to a windfarm which will requires distribution- network u/g, substation tx, maintenance & failure over that 25yr period? Most likely providing rather intermittent power unless situated at sea which involves considerable cost & likely higher ongoing maintenance costs re marine environment, storms, failures, accidents.

[The Natural Philosopher]

No, they don't. You have no idea how much storage the country needs to run e.g. for a day or two without wind, if windmills are all you have.

No, I have done the maths, that's all.

Basically, if it were that cheap and easy we would have done it years ago.

I spent a long time doing the maths on alternative energy, and the costings. 99% of it is simply pie in the sky.

If we had unlimited energy to build and unlimited power to build with, we could do it.

The world would not be worth living in, mind you. One vast industrial landscape of power generation.

[The Natural Philosopher]

Try doing the sums.

That will get you the answers.

You can do sums can you?

[The Natural Philosopher]

Thank you.