12 kWh for 87p sounds like a good deal - I wonder if it's a conversion of US prices or something. Other than that, is there anything interesting or surprising in that article at all?

Credibility check: the rough rule of thumb is £1/W·a (watt·year). That an iPad, averaged over all time including when it's not in use, and allowing for charging inefficiencies would use a bit less than 1 W sounds about right.

A few years back I was listening to a Radio 4 piece about the power consumption of DAB radios. The BBC spokesperson explained, without any recognition of the significance, that a DAB radio consumed between 12 and 20 times the energy of an analogue radio. Hmm. Just think about all those batteries.

It got me thinking. Have you considered all the energy consumed by all those extra set-top boxes tagged onto or TVs. The government want to sell the spectrum currently occupied by analgue but just what does that cost in extra generation.

It's not just old TVs. We have a very recent (less than 2 years LED TV). It has built in Freeview as well as analogue tuners. However, it turns out that this is not a HD Freeview tuner despite the fact that it is a full HD TV. As it happens we use a Freesat HD box because it is just better than Freeview. So every time we switch on, we fire up three tuners.

I think the addition of radio to freeview was a mistake - how many tellies get left on just so you can "tune in" ?

Our telly is a rather embarrasing plasma (takin an evil 250W), but the set top box is good - a genuine 1W on standby. Lots of set top boxes take 15-25W in "standby". At long last, set top boxes can be as low power standby as those VHS recorders of yester-year ! I think the high standby is because manufacturers use software* based solutions, allowing them to omit a cheap seperate timer chip to allow it to start from standby for timer-record.

*generally linux, but not really it's fault

Last night I set the freesat to record a film we wanted to watch later. Hmmm. On Friday we decided that we would start to turn off the TV and all related boxes at the plug and stop leaving it all on standby, so as we got up to go to bed I did the righteous thing.

Bugger!

Posted By: JoinerIt's a UK-based internet publication, Ed.

But the Electric Power Research Institute that they're quoting is American, so Ed is probably right.

How many cubic miles of water lifted how high is that?

12 tonnes 36 km
or
432 tonnes 1 km
or
1296 from the nearest coast to me to the nearest sizeable carne near me
But allowing for 75% efficiency that will be 1620 tonnes.

Me neither.
PE=mgh (J)

Edited from earlier as too tired

I looked it up today on the infallible Wikipedia: the potential energy of lifting 1kg up to geosynchronous orbit only seems to be about 15kWh or £2 of electricity!

Rgds

Damon

(I think that if ST manages to raise 1kg to geosync orbit, then while he's not looking I'll sell on the service as the space elevator at a nice little mark-up: move over Space X!)

This emmet might be heading your way in the first week.

No - the point about a space elevator to geosynchronous orbit is that centrifugal force does the lifting. Innit?

The problem is that the force is applied at the top, so a lifting cable has to be dropped down to the surface - and the weight of that length of cable is so vast that it wd have to be impossibly huge in cross sect area to support its own weight.

Why not just tether the weight to a load of pigs and get them to fly it into orbit.

Posted By: fostertomNo - the point about a space elevator to geosynchronous orbit is that centrifugal force does the lifting. Innit?

The problem is that the force is applied at the top, so a lifting cable has to be dropped down to the surface - and the weight of that length of cable is so vast that it wd have to be impossibly huge in cross sect area to support its own weight.

No, the fact that, as you point out, the lifting cable is dropped from above shows that objects still have weight as they track up the cable. The weight and strength are not beyond the theoretical reach of materials made from carbon (or boron-nitride) nanotubes, as I understand it. It's "just" an engineering problem now. The advantage of a cable is that you don't have to supply power to hold an object wherever it is, only to move it against the force of gravity. A rocket has to expend power just to hover. A stick can support the weight of a rock with much less energy use than if you hold the rock up yourself.

Posted By: DamonHDI looked it up today on the infallible Wikipedia: the potential energy of lifting 1kg up to geosynchronous orbit only seems to be about 15kWh or £2 of electricity

OK, I agree with Wikipedia now. The figure I have is 60 MJ/kg or 16.67 kWh/kg. Impressively low.

Let's ALL go and visit ST next week!