Boiling a litre of water

[Geoff]

The AECB (http://www.aecb.net/forum/index.php?topic=1064.0)board quotes DEFRA CO2 figures for electricity: " The correct figure is now 0.527kgCO2/kWh http://www.defra.gov.uk/environment/business/envrp/pdf/conversion-factors.pdf " However the originator of the topic says: " My research shows that it will be approx 1kg but this is based on some very rough assumptions which aren't sufficiently reputable and referenceable." Heating 1 kg of water by 80 degC is 80(degC) * 4.2(joules/degC/gm) * 1000 (gm) = 336,000 joules. = 0.336 megajoules 1kw/hr = 3600(sec) * 1000 (joules/sec) = 3.6 megajoules This gives 0.527 * 0.336 / 3.6 kgCO2e = 0.05 kg. If a litre of water is allowed to boil dry the heat reqiured is 1000(gm) * 2260 (joules/gm)= 2.26 megajoules Unfreezing a litre of water requires 1000(gm) * 334 (joules/gm)= 0.334 megajoules

[Geoff]

In"'Carbon cost' of Google revealed " (http://news.bbc.co.uk/1/hi/technology/7823387.stm)
the BBC report estimates by Alex Wissner-Gross, Ph.D., an "Environmental Fellow at Harvard University",
that:

      Two search requests on the internet website Google produce "as much
      carbon dioxide as boiling a kettle", according to a Harvard University academic.

and

    a typical Google search on a desktop computer produces about 7g CO2.

This must assume that a boiling a kettle produces 14g CO2. It doesn't fit with the
Green Ration Book estimate of 50g.

Sadly the BBC piece gives no link to the source, just a link to the CV of Alex Wissner-Gross.
Also the link to the Google blog disputing this is given simply as

    http://googleblog.blogspot.com/

That will be of little use as the blog moves on. A more helpful link is the permalink:

    http://googleblog.blogspot.com/2009/01/powering-google-search.html

Here Google strongly dispute the BBC figure, claiming 0.2gm of CO2. Assuming that
7gm CO2 can be taken to mean CO2 equivalent(*), current Green Ration Book entries
would equate 1 million Google searches with one return flight to Australia or
700 Google searches for a cheeseburger. It the Google figure of 0.2g per search is
accepted then

    One return flight to Australia = 14 million Google searches
    One cheeseburger = 9,800 Google searches

The BBC Click programme (http://news.bbc.co.uk/1/hi/programmes/click_online/)
recently had a piece about a supermarket becoming more sustainable by
printing on both sides of the till roll. Assuming 50 sq cms of till roll has the same
carbon footprint as 50 sq cms of the Daily Mirror, the the saving is about
0.2g CO2e - enough to drive the shoppers car 1 meter.

How silly can the BBC get!



* http://en.wikipedia.org/wiki/Carbon_dioxide_equivalent

[Tazz64]

What is the deal of boiling a litre of water? is there any problem to it?

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doctor is out