User:Johnbibby/Sandbox/Greenies/PC Energy Report

UK Businesses Waste £300 Million Per Year Powering Idle Computers
This recent article is a good example of "the statistical scare" - using numbers to imply that something is very important and urgent (when it might not be).

We need to examine such claims very carefully - just because a number has got lots of noughts on, it does not mean it is important (especially when other relevant numbers might have even more noughts on).

In addition, a big number may just be big because it applies to a large population: if you gave just 10p to everybody in the world, that would be a very big number. However, it is a very small number compared with the world economy. (Exercise for the Reader: There are 6.5 billion people in the world. How much would it costs to give each person just 10p?)

This is one reason why statistical literacy is so important: it can help you to do rough back-of-the-envelope calculations in your head (or on the back of an envelope). Then you can assess how important the number actually is.

Here are some statistical quotes from the article:

 * If all the 17 million UK office workers turned off their computer at night the carbon saving is equivalent to removing 243,440 cars from UK roads
 * UK organisations are wasting £300 million per year powering idle computers.
 * If the 17 million workers in the UK who regularly use a computer turned it off at night, it would reduce carbon dioxide emissions by 1,329,182 metric tons, the equivalent of removing 243,440 cars from the road
 * If a UK business with 10,000 computers leaves them on all night for one year, it will cost £174,720 and emit 828 tonnes of CO2.

Let's unpack these, one by one: It's interesting here how a very rough-and-rounded figure ("17 million") is converted into a very precise number of cars (243,440). We may call this the "mixed precision fallacy". It is a common occurrence.
 * If all the 17 million UK office workers turned off their computer at night the carbon saving is equivalent to removing 243,440 cars from UK roads

How can they be so precise? - are they sure it is not 243,450? or even 250,000, which has the advantage of being a nice round number (quarter of a milllion)?

It's also not clear what "removing xxx cars from the road" means? - are we removing it for good, or just overnight, or what? Also, is the supposed equivalence in terms of all energy costs, or fuel costs, or what?

However, taking the last figure (250,000), we basically have that 17 million computer turn-offs is supposewdly equivalent to removing one-quarter of a million cars from the road. Here we must turn to ratios - an inval;uable ally in debunking scare-stories (or at least putting them in perspective).

The ratio 17-million divided by 250,000 gives us 68 million to one million or 68 to one. That is, each car-removal is equivalent to 68 computer turn-offs. Is this plausible? Could it mean that each computer turn-off (overnight) is equivalent to the fuel that 68 cars would use (overnight)? Well that seems highly unlikely, but at least we now have a handle on what exactly they are claiming. (They may be allowing for the fact that of the 68 cars, 50-60 of them may be stuck in their garages all night.)

Let's suppose that of the 68 cars, 10 of them move overnight, and do an average of say 10 miles each. That's 100 miles, or say 3 gallons or 15 litres of, fuel. So one computer turned off saves the equivalent of 15 litres of fuel - worth say £15.

Seems unlikely to me!

Well I can believe that. After all, 'UK organisations' are generating income of about 1 trillion pounds per year (a million million). Perhaps 1% of this goes on computer power - that's £10 billion. So £300 million 'wasted' is actually a rather small fraction. Verdict: no surprise.
 * UK organisations are wasting £300 million per year powering idle computers. 

This is another case of the "mixed precision fallacy" (see above). It introduces the equivalence  1.25 million (roughly) metric tons CO2 === .25 million (roughly) cars. That's about 5 to 1 (ratios again!) I don't know what this means. But the statistical ineptitude sure scares the hell out of me! (Which is the desired effect).
 * If the 17 million workers in the UK who regularly use a computer turned it off at night, it would reduce carbon dioxide emissions by 1,329,182 metric tons, the equivalent of removing 243,440 cars from the road


 * If a UK business with 10,000 computers leaves them on all night for one year, it will cost £174,720 and emit 828 tonnes of CO2.

Here at last is something I like - a number I can handle (10,000). Taking ratios again, it's saying that each computer overnight costs £17.47 per year (or about 5p per day). I can believe that! It's about have a kilowatt-hour unit of electricity, or about 50 watts per hour.

UK Businesses Waste £300 Million Per Year Powering Idle Computers

 * March 25, 2009

If all the 17 million UK office workers turned off their computer at night the carbon saving is equivalent to removing 243,440 cars from UK roads

Wednesday 25th March will see the launch of the third annual PC Energy report; the international study examines the habits and attitudes of UK, US and German office workers towards the environment and workplace energy consumption.

1E and the Alliance to Save Energy commissioned the report to show how organisations can easily cut energy costs and reduce their carbon footprint by better understanding user behaviour in the workplace. The report reveals that while cost control is high on the agenda, UK organisations are wasting £300 million per year powering idle computers. But UK workers lead their US counterparts in making the environment a priority

The headline statistics:

Workplace habits • The environment is the main reason why 27% of UK workers turn off their computers at night compared to only 10% in the US

• The information and communications technology (ICT) industry generates 2% of the world’s carbon emissions, equivalent to aviation industry. Of this 2% up to 39% is created by PC’s and monitors Environmental Impact

• If the 17 million workers in the UK who regularly use a computer turned it off at night, it would reduce carbon dioxide emissions by 1,329,182 metric tons, the equivalent of removing 243,440 cars from the road • If a UK business with 10,000 computers leaves them on all night for one year, it will cost £174,720 and emit 828 tonnes of CO2

UK vs. US Asked why they turn off their computers at night:

• UK employees were the most idealistic in their responses, with 27 percent saying they power down PCs to help the environment

• The most common reason given by US employees (21 percent) was practical - to ensure that the PC works properly the next day

• Asked whether their employers should be doing more, responses revealed:

• Both US and UK employees believe their employers should be doing more to reduce power consumption (63% and 67% respectively)