Joined: May 02, 2005 Posts: 3420 Location: Oh really?
Posted: Wed Jun 08, 2005 10:44 am Post subject: Megawatts of Waste
US statistics show approximately 100 million computer in use during 2001.
The same data table shows only 6-7% of these are left on 24 hours a day.
Even in hyper efficient energy save mode, that is about 100 million watts.
Yes, that's right, 100 Megawatts, and I think I am being generous on the efficientcy of power save systems.
I am not sure I believe the 6-7% figure. "Conventional wisdom" once delarered increased life and stability by leaving the machines run continually. Many people never abandoned the habit(I am one of them).
Turn 'em off!
I am curious abolut street lighting also. The only data that came up on a quick Google was that ONE county in GB supports 140,000 street lights.
that is a 70 Megawatt load for ONE county in ONE nation! _________________ "It's not demand; It's not supply.
It's coming up with credit to buy"
Joined: Dec 08, 2004 Posts: 1583 Location: Nez Perce Nation
Posted: Fri Jun 10, 2005 3:49 pm Post subject:
8 watts of light. Good enough for a mole, I guess. _________________ "Modern Agriculture is the use of land to convert petroleum into food."
-- Albert Bartlett
"It will be a dark time. But for those who survive, I suspect it will be rather exciting."
-- James Lovelock
Joined: Jul 18, 2004 Posts: 198 Location: S. Yorkshire, UK
Posted: Mon Jun 13, 2005 4:46 pm Post subject:
[q]US statistics show approximately 100 million computer in use during 2001.
The same data table shows only 6-7% of these are left on 24 hours a day.
Even in hyper efficient energy save mode, that is about 100 million watts. [/q]
It's worth noting that 'standby' power is a huge problem. Think how many devices you have in your home / workplace that are on 'standby' - battery chargers, VCRs, cordless phones, Cable boxes, PCs, TVs, Microwave ovens, every one of those 'pregnant plugs' for mobile phones, and other gadgets. These all take a little bit of power, whether they are in use or not, or visibly 'switched on' or not.
In Europe, it's estimated that around 10-15% of domestic electricity consumption is attributable to 'standby' consumption. It's slightly less in the US, due to the generally much higher electricity consumption per household.
Thankfully, there is now legislative pressure on manufacturers to improve energy efficiency. E.g. the charger for my previous cell phone would take 4 W of power when plugged in, rising to 8 W when delivering 2 W to my phone during charging. On my new phone, the charger takes < 0.5W when idle (below the limit of my measurment equipment) and 3W when delivering approx 2 W to the phone.
Street lights are a major power consumer, but they do provide a very useful purpose and are directly responsible for improvements in road safety and reduction in crime in urban areas. However, because of the cost of powering them, there are initiatives to improve energy consumption.
New lights can bring substantial benefits. Advanced reflectors direct more light at the road, and less into the sky (in the form of light pollution). Electronic controllers use less power and are more reliable, while providing improved controllability. In some areas, the lights have programmable brightness - so very late at night (after midnight or 1AM, it is possible to dim the lights to half power).
Joined: May 06, 2005 Posts: 209 Location: North Texas
Posted: Wed Jun 15, 2005 3:34 pm Post subject:
Big things like computers, T.V.s, and VCRs that are off but still plugged in waste energy also. It's pretty small for each one, but multiply that small amount by 500 million or so and it adds up to a significant amount. I don't have the exact figures, but from memory it was 2 average power plants energy output per day wasted.
Big things like computers, T.V.s, and VCRs that are off but still plugged in waste energy also. It's pretty small for each one, but multiply that small amount by 500 million or so and it adds up to a significant amount. I don't have the exact figures, but from memory it was 2 average power plants energy output per day wasted.
I read a statistic once that if everyone in the USA unplugged their TV when it was NOT in use, that would save the equivalent of 2 Hoover Dams. The Hoover dam is about 2100 MW of energy (or 2 nuclear power reactors).
So unplug all TVs just when not using them and that reduces our need for about 4 nuclear power reactors.
Joined: Jul 25, 2004 Posts: 681 Location: Hunter Valley, New South Wales, Australia
Posted: Sat Jun 25, 2005 9:05 pm Post subject: Re: Megawatts of Waste
MD wrote:
US statistics show approximately 100 million computer in use during 2001.
The same data table shows only 6-7% of these are left on 24 hours a day.
Even in hyper efficient energy save mode, that is about 100 million watts.
Yes, that's right, 100 Megawatts, and I think I am being generous on the efficientcy of power save systems.
I am not sure I believe the 6-7% figure. "Conventional wisdom" once delarered increased life and stability by leaving the machines run continually. Many people never abandoned the habit(I am one of them).
Turn 'em off!
I am curious abolut street lighting also. The only data that came up on a quick Google was that ONE county in GB supports 140,000 street lights.
that is a 70 Megawatt load for ONE county in ONE nation!
I cannot comment on computers, because I am not much of an expert on 'em...BUT , because I'm pretty heavily into astronomy, I CAN comment on lights...MOST of our lighting goes into SPACE (so the extra-terrestrials don't bump into our satellites, I presume). It does NOT go down onto the ground, where it is needed.
We could solve an awful lot (not ALL) of our current (pardon the pun) "energy shortfall" by simply having lights that direct their light DOWN and not in-every-random-direction.
There's pictures at NASA (do a google serach for them) of all of the Earth's city's lights, as seen from space.
We're no longer talking about MEGAWATTS hours, we're talking about hundreds of GIGAWATT hours being utterly wasted, if not tens of TERAWATT hours, measured over the course of a year, if one takes the combined lighting of ALL of the Earth's cities, big and small.
Joined: May 31, 2004 Posts: 920 Location: Brno, Czech rep., EU
Posted: Sun Jun 26, 2005 6:13 am Post subject:
Just buy smaller car or better insulation for your house and you will save many times more energy than by disabling public lights or unplugging all devices..
Don't forget that your cars have power consumption of up to 75 000W (for european small diesel engine - efficiency 50%, power 50hp) or up to 500 000W if you have a SUV (efficiency 35%, power 230hp)..
So think twice .. 1 hour of driving consumes energy equal to 5000 hours (= 7 months!) of old light bulb or inefficient computer on standby, or about 500 000 hours (=57 years!!) of standby of modern efficient devices (many have standby consumption < 1W).
Drive less, buy smaller car and you will save MUCH more energy..
Joined: Jul 25, 2004 Posts: 681 Location: Hunter Valley, New South Wales, Australia
Posted: Sun Jun 26, 2005 8:10 pm Post subject:
Hi Licho
Licho wrote:
Just buy smaller car or better insulation for your house and you will save many times more energy than by disabling public lights or unplugging all devices..
Don't forget that your cars have power consumption of up to 75 000W (for european small diesel engine - efficiency 50%, power 50hp) or up to 500 000W if you have a SUV (efficiency 35%, power 230hp)..
WOW, that's one massively efficient SUV! I've heard quotes for o'all efficiency for normal (ie: NON-SUV) cars as being 12% or thereabouts....After all, RAILWAYS come in at 6 to 9 TIMES the efficiency of road transport - and 6 times the efficiency , if one accepts 35% = 210% for rail travel...which I find difficult to beleive.
6 times 12% = 72%, which is more beleiveable.
Licho wrote:
Drive less, buy smaller car and you will save MUCH more energy..
Yup, I agree...AND travel by train, where possible.
Joined: May 31, 2004 Posts: 920 Location: Brno, Czech rep., EU
Posted: Mon Jun 27, 2005 4:13 am Post subject:
Yes, you are correct, I made some googling for efficiencies of engines themselves and these were top theoretical numbers I found. Other mechanical stuff in cars probably decreases it to your figure. (But I was calculating power consumption from engine power output, so I could ignore rest of the car).
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Good enough for a mole, I guess. 
