commentary Why would a super-efficient Australian datacentre produce more carbon emissions than an equivalent sized, yet hopelessly inefficient and power-hungry datacentre in Germany?
If you are a CIO looking to buy green IT certified products or services, be wary of vendors that link energy efficiency with reduced carbon emissions, as the two do not necessarily equate.
The amount of carbon emissions that are saved by reducing the energy used depends on how that energy is generated. Unfortunately in Australia, we are particularly dependant on coal for power generation, and as such, one watt of Australian power produces more emissions than one watt of German power.
Let's set the record straight on what "carbon emissions" actually are.
The first and most confusing thing about carbon emissions is they do not necessarily refer to carbon dioxide, the gas product of burning any hydrocarbon fuel such as petroleum or coal.
"Carbon emissions" are in fact scientific shorthand for a whole aggregate of greenhouse gases. As carbon dioxide is by far the most common greenhouse gas, all greenhouse gases are multiplied (or divided) by their relative effect compared carbon dioxide, in order to create a standard measure.
For example, methane, which is a farming by-product and is produced by rotting organic material, is 25 times more powerful than carbon dioxide as a greenhouse gas. So 40kg of methane is counted at "one tonne of carbon emissions". Another great example is nitrous oxide, which is 296 times more powerful than carbon dioxide, which means 3.4kg of nitrous oxide is "one tonne of carbon emissions". This essentially means that one tonne of "carbon emissions" could be as little as 3.4kg of gas.
This begs another question, how big is a tonne of carbon?
Bearing in mind that gases have a huge volume for not much mass, a tonne of pure carbon dioxide at 25 degrees Celsius and 1 bar is approximately 560,000L, which is 560 cubic metres. That's roughly 20 percent of an Olympic-sized swimming pool. Of course the reason why scientists measure gases in mass rather the volume is that mass is independent of temperature.
So if all greenhouse gases produced by industry get converted into a mass of carbon dioxide, what is a greenhouse gas? A greenhouse gas is any gas with an infrared (IR) absorbance, which surprisingly means, that almost every gas known is a greenhouse gas (with the exception of a few including some diatomics and the noble gases).
Coal is particularly bad because burning it produces all kinds of powerful greenhouse gases in addition to carbons dioxide, such as nitrogen and sulphur oxides -- which also cause acid rain.
With analyst firm Gartner claiming that Green IT is the number one issue for CIOs, terms like "carbon emissions" and "carbon footprint" are being bandied about with most people completely unaware of their actual effect on the atmosphere.
So for all those Australian CIO's who are looking at investing in power-efficient "green" products: don't believe the greenwash, as it's mostly just hot air.