Custodian Data Centre publishes live PUE on website

With an award winning fresh air cooling system the Kent data centre is realising some notable results with annualised figures of 1.16 and a PUE regularly as low as 1.09 during the cooler months.

Originally devised by the Green Grid to enable individual data centres to track the progress of their own energy efficiency (and to highlight the levels of energy being used by their infrastructure) PUE is the ratio of the total energy used to run the datacentre (including all supporting services) divided by the energy required to run the IT equipment housed in it. Thus the ideal target for PUE was and is to get as close to 1.0 as possible, by reducing the additional power required by the infrastructure, such as cooling, to as low an amount as possible.

“The focus for our infrastructure design is primarily uptime, followed by efficiency” explains Technical Director Rob Williams. “By not requiring chillers for 95% of the year we are therefore not affected by chiller failure. Our system achieves both efficiency and resilience by running mainly on UPS backed fans only. However our PUE does suffer slightly because of our 2N power infrastructure, whereby each UPS can only operate below 50% capacity in case of failover. The UPS losses are therefore proportionally higher as a result compared to facilities with less resilient approaches to power provision.”

Despite these UPS losses Rob Williams goes on to say that “as a company Custodian Data Centre are proud of our efficiency and are happy for our customers to see what we are achieving at any given point. As a colocation facility our customers appreciate that this is beneficial for both the environment and our pricing structure.” No other UK based colocation facility that Custodian are aware of are doing this.

Data Centres across the world often quote theoretical PUE (e.g. at optimum load) and as such it is often hard for prospective customers to compare like for like. Additionally competing data centres looking to compare their PUE’s sometimes use creative timing to reduce the ratio and produce better looking numbers, such as taking measurements on a cold day when the chillers were not at peak levels and IT equipment is working very hard. In these situations the PUE often reported by data centres is a snapshot of their operating capabilities or a calculation of the best result if full and working at its designed optimal level - rather than their day-to-day performance.

Rowland Kinch, CEO of Custodian Data Centre said of the decision to share Custodian’s live PUE that “by publishing real-time PUE, Custodian Data Centre is challenging the PUE debate by introducing transparency into the mix”.