Whether you are considering the environment, your public image or your bottom line, it makes sense for your data centre to be as energy efficient as possible. There have been many estimates of the amount of electricity consumed by data centres, some suggesting that in the UK it could be as high as 4% of total consumption. The EU Code of Conduct for Data Centre Energy Efficiency uses a figure of 56 TWh per year for the EU as a whole and suggests that this will increase to 104 TWh per year by 2020. Whatever it is it is a lot, and it would be no bad thing to try to reduce it or at the very least curtail its growth.
Let’s put this in perspective..
Compared with a normal office block or residential property data centres use vastly more electricity. The average household in the UK uses approximately 5000kWh of electricity over 12 months. In comparison a micro data centre with just 20 moderately loaded cabinets and a PUE of 1.4 uses 981,120kWh in the same time. A large facility housing 1000 moderately loaded cabinets with a good PUE of 1.2 uses 42,048,000kWh. This is the equivalent of 8,409 households.
Although the numbers above are pretty big and there is no denying data centres, through their energy consumption, do produce a lot of CO2 , the highest estimates for Northern Europe’s data centre energy consumption are around 65tWh. This produces around 32,500,000 tons of CO2 per year. In comparison the lowest estimates for CO2 produced by Europe’s air travel is 125,000,000 tons of CO2 per year. This means almost all the CO2 produced by all of Europe’s data centres could be “off set” by grounding 1 in 4 flights. Food for thought.
IT Equipment Energy Efficiency
This falls outside of our scope as it depends on the efficiency of the hardware and software in use. Great improvements have been made in recent years with manufacturers producing equipment that provide more compute per kilo Watt. Developers are also creating more efficient applications while IT managers are virtualizing and consolidating their servers, all resulting in more energy efficient data centres. As yet though there is no agreed metric for the efficiency of the IT load as a whole, as this will require an industry agreed means of measuring and comparing the “output” of the IT system themselves. Some organisations have created their own internal metrics such as financial transactions per Watt and searches per Watt. These are very useful for them and can help decisions regarding data centre deployment and development. However due to each organisation being slightly different these metrics cannot be used in a universal way.
This is something that the EU CoC hopes to address in the near future.