[LINK] Australian energy efficiency standards for personalcomputers and monitors

[steve jenkin]

jim birch wrote on 18/10/07 11:11 AM:
> I bet some Chinese engineer has figured the number of power stations
> this initiative will save, not to mention the amount of manufacture of
> different wallwarts avoided.  I'd expect some serious numbers.
>   
Australia:
People: 20M
Houses: ~10M
Phones: ~10M [wired]
Mobiles: 18M [not all consumers]

My Nokia charger: 5.3V @ 0.5A ~= 2.5W [similar to USB]
Charges my phone in under 30 mins. Or ~1Whr/day = 0.33KwHr/year
It's light and 'autoranging' - so it's Switched Mode. At least 90%
efficient *under load*

For Aus, ballpark mobile phone charge consumed pa:
    18M * 0.33KwH = 6GwH
    => or about 675kW continuous...

Scaled up to 1Bn (*50) for China
    => 33MW continuous.

Generators come in sizes like 660MW. Power stations comprise multiples
of these..
That's not a whole lot in the scheme of things.
*refrigerators* at 50-100W continuous are really a big deal.
As are poor quality TV/VCR/DVD standby ~5-10W.
And leaving your PC turned on all day: 150-250W.  Really bad.

Australia consumes about 2.5kW per house continuously. Around 60kWH/day.
Peak is much higher. [5-10 times].
Airconditioning & heating at 5kW and 4-6 hours/day make a *huge* impact.

What about the 'standy power' use - that's the main argument...

Switched mode supplies are very efficient - and they have very low
standby consumption. Basically the current to run the control circuitry
[they know when there is no load...] That would be under 1ma.
[I don't know the idle losses in small transformer/rectifier supplies]

To be generous, let's assume 5ma - 1% of rated power. And spread that
over 24 hours - or 25% of a full-hour operation.
I've assumed only 0.5 hour charging/day - so 50% of this.

For Australia, mobile chargers doing nothing, can't add more than ~300kW
of load.
And China, maybe 15MW...

cheers
s

-- 
Steve Jenkin, Info Tech, Systems and Design Specialist.
0412 786 915 (+61 412 786 915)
PO Box 48, Kippax ACT 2615, AUSTRALIA

sjenkin at canb.auug.org.au http://members.tip.net.au/~sjenkin