Facebook Finds Data Centre Disclosure Is A Mixed Blessing

Facebook is being commendably open about its energy use and carbon footprint. But the company might not be pleased with the coverage it got.

The social giant published its 2012 carbon footprint a week or two back, along with some infographics on the  Green On Facebook page. But there’s a lot of information there to unpack – and some people may have read it different ways.

Facebook use = three bananas

Facebook quotes its energy use “per user” – taking its energy and emissions and dividing those by the number of users. In 2011, its actions caused 249g of greenhouse gas emissions per month, per active user. but this has gone up in 2012, to 294g.

Facebook says its per-user footprint has increased “only slightly” – and this is true. The emissions have gone up by 20 percent per user, which is a big fraction, but the energy used by Facebook is still pretty low – about as much as one latte per user  ,or three bananas, the company says – for a whole year!

So on average, your Facebook energy use has gone up by about half a banana.

The word “average” there is interesting. How much has Facebook usage changed? Are active users pumping more photos onto the site, or messaging more? This whole area changes so fast, that any change in users’ carbon footprint is more likely due to usage patterns than anything Facebook itself is doing.

So what about the overall figures? The company’s total emissions went up by 35 percent over the year, and its energy usage likewise climbed from 532 GigaWatt hours, to 704 GigaWatt hours.

That’s to be expected, given the company’s expansion.

PUE goes up… by a fraction

And how efficient is it? The company is investing in facilities powered by renewable energy, such as the one in Lulea Sweden, and that should improve things, but this year, it’s got slightly worse.

The overall Power Usage Effectiveness (PUE) has gone up slightly. It’s gone from 1.08, to 1.09.

That’s not a big change. By now, TechWeekEurope readers know the context of the PUE efficiency measure. PUE is the total power used by the data centre, divided by the power delivered to the racks. The (impossible) ideal is 1.0, and most data centres hit 1.5 or higher.

This means that  Facebook is currently wasting only 0.08 of a Watt for every Watt used – and the change over the year is 0.01 of a Watt for every Watt used. Facebook is still far closer to the ideal than it is to the industry average .

The energy mix is more disappointing. Facebook has gone from using 23 percent renewable energy to 19 percent, while its coal use has gone from 29 percent to 34 percent.

Again though, this is all going to plan: the company is in the process of setting up its Lulea facility, which will be all-renewable, and very efficient (Sweden’s low air temperature should mean no other chilling is required). But so far Lulea is only in a small start-up mode.

Changing the stats

Again, these statistics are a moving target – Facebook has changed the way it calculates its energy use – specifically the “Scope 2” emissions caused by its energy suppliers.

now these emissions are important in moving to renewable energy. If your energy supplier uses coal, your Scope 2 emissions will be high. If the supplier uses renewable energy, they could be close to zero.

But only if you have the right data. Facebook used to use “location-based” averages, based on the typical mix for a given place. So, for Sweden the local average includes some fossil fuel.

Facebook is moving to “contractual” figures, based on the actual projects that its utility firm uses to supply it. In Lulea, that means its Scope 2 emissions go to zero, as it has a contract to use electricity only from renewable sources.

This change in stats is a very good thing. and it doesn’t benefit Facebook in every case. For instance, its Prineville centre apparently causes higher emissions this year – because the site actually uses more non-renewable electricity than the average of the power supplied in that area.

In future though, the change means that Facebook will get more credit for good environmental choices – and any old, dirty power it uses will be accounted as such. 

What about the coverage?

But is all this helping Facebook? Maybe not.

Google News lists only one report based on this story – and it’s not much of a story. Sustainable Business News spotted the 35 percent increase in Facebook’s overall emissions, turned that into a headline, and rounded it up with two other not-very-related stories, ignoring most of the data Facebook had published.

And that is all.

Facebook must be wondering why it bothered.

A version of this article has appeared on Green Data Center News.

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