Intelligent CIO Africa Issue 67 - Page 47

FEATURE : DATA CENTRES measure , the Power Usage Effectiveness ( PUE ) metric has become a de facto industry standard for measuring how efficiently a data centre uses energy . To improve efficiency , data centres need to deploy Heating , Ventilation and Air Conditioning ( HVAC ) technology that will deliver a low annual average PUE .
A few years ago , the annual average HVAC PUE ’ s were around 1.9 . Current PUE figures hover around 1.5 and there is constant effort going into lowering this to 1.0 . Incorporating free cooling , free heating and specifications on the efficiency of operating equipment in the HVAC designs lowers the annual energy utilisation and drives down the annual average PUE .
Another strategy to increase a data centre ’ s energy efficiency is widening its internal temperature and humidity range and performing upfront planning to ensure ease of maintenance . It is also important to consider improving the power usage of IT equipment by lowering the payload power that it requires . Servers consume 60 % of this , so that further efficiencies can be realised by cleaning up server workloads and eliminating unnecessary usage , virtualising more workloads and replacing older and less efficient servers with new ones .
Finally , data centre owners need to optimise physical data centre space , particularly for data centres that were built before server virtualisation became commonplace . Less space needed equates to less cooling and thus power savings .
Energy efficiency improvements alone will not stabilise power supplies , though . In the urban context , renewable energy from rooftop solar PV panels can be incorporated into a build to offset some of the data centre ’ s reliance on the local grid . However , the power contribution from a rooftop solar microgrid would not be sufficient to meet the demand of a power-hungry data centre . For this reason , we are seeing more interest in alternative energy solutions that comprise of a tri-generation plant using natural gas to power the data centre and off grid , with diesel generator backup for downtime periods . Important to this is securing a site in a hotspot area with access to gas lines to secure a consistent supply .
Though tri-generation and improved energy efficiency are all steps in the right direction , further thought must be given to renewable energy if net zero is the goal . Fortunately , Africa ’ s potential for producing renewable energy is vast . The challenge is space , which is not readily available in urban centres .
To reach net zero , data centre owners could look to trends out of other markets where investing in
renewable energy plants and microgrids – like a solar or wind power farm for a large data centre – are showing promise . In Africa , this approach opens new opportunities to establish data centres in more remote parts of the continent that previously have not been considered due to a lack of infrastructure , but where space is more readily available . This approach feeds the data centre directly from its own self-sustainable supply of renewable energy , while also boasting cleaner energy use and improved carbon reduction .
In this context , the business case for solar is particularly strong . South Africa , for example , receives more than 2,500 hours of sunshine per year , with average solar-radiation levels ranging between 4.5 and 6.5kWh / m 2 in a single day . The country ’ s average solar radiation of about 220 Watt per square metre is more than double that of Europe ( 100 W / m 2
). Solar , therefore , is one of the most promising renewable energy options to reduce dependency on the grid . The Northern Cape has become a hotspot for solar power plant investments given the impressive solar power generation potential in the area – and we have seen successful examples of solar-powered data centres
Craig Blankers , Regional Director , WSP in Africa




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