Thinking about colocation in a green data centre? Congratulations, that’s great news for the planet and for your budget as green data centres are often more cost effective than traditional facilities. But the devil is in the details: There are different shades of green, just as there are different levels of cost effectiveness. Here are three things to look out for:
1. Energy Reusage Effectiveness (ERE)
ERE indicates how well a data centre reuses energy. The majority of data centres simply let the excess warmth escape into the atmosphere, increasing the greenhouse effect and creating a heat island around the building. This microclimate effects both fauna and flora in the vicinity. However, an increasing number of data centres take advantage of this excess warmth by using it to heat a network of properties or an individual building, or to power a factory.
2. Power Usage Effectiveness (PUE)
PUE describes how successfully data centres keep energy in the system and how much they lose along the way. A low PUE figure means high energy effectiveness and a PUE of 1 indicates that no energy is wasted at all. In 2011, the Uptime Institute said that data centres around the world scored an average PUE of 1.8.
3. What kind of electricity does the data centre use?
People often use the term green data centre for a facility that uses renewable energy. A good ERE and PUE score means nothing if a data centre burns fossil fuels, which, of course, emits carbon dioxide.
So for a data centre to be green to the core it must be driven by renewable power, reuse excess heat and not waste any energy. But why stop here? Data centres that use their excess heat to power systems that would have otherwise been driven by fossil fuel can become climate positive, reducing more emissions than it produces. You can read more about the world’s first climate positive data centre here.