Deloitte with Tesco.
Tesco has set itself demanding environmental targets, including a 50% cut in emissions from existing buildings by 2020. The supermarket chain's global carbon footprint currently stands at 4.1 million tonnes of CO2 every year: electricity accounts for half this total, refrigerant for a quarter, and the rest is split between diesel, natural gas and business travel.
IT accounts for a small, but still significant, 3% to 4% of Tesco's footprint. But IT director Nick Folkes was concerned to discover that Tesco's existing 20-year-old data centres were running out of power and space. Traditional solutions to that problem would mean a hike in emissions. All other things being equal, more computing power means more electricity, which generates more heat, which requires more electricity for air conditioning. All of which adds up to an unacceptable rise in carbon emissions. Explains Folkes: 'Deloitte was engaged to help us not only understand how we could improve the efficiency of our data centre facilities but also the IT infrastructure within them.'
Deloitte's team of 10 was led by associate director John Winstanley, head of its Green IT practice. The project, split into two stages, ran from January to June 2008. In the first phase, Deloitte measured and analysed Tesco's data-centre facilities and its IT infrastructure. The consultancy selected and worked with a specialist partner in energy-efficient facilities consulting, EYP, to assess the energy output of the infrastructure supporting the data centres. EYP investigated the mechanical and electrical infrastructure for power consumption, looking at hardware such as generators and air-conditioning. Meanwhile, Deloitte experts ran their eye over the IT infrastructure, including Wintel, mid-range, mainframe and storage environments and the management of the data-centre space.
These measurements had to be taken without risking disruption to services. The consultancy's engineers overcame this problem by taking measurements further away from critical systems, then applying their experience and knowledge to calculate the power used. They coupled manufacturer plate-readings with readings taken at power distribution unit level to calculate the power draw of the IT equipment. Then Deloitte mined all this relevant data from different sources, pulling the information together and extrapolating key details.
What did it learn? Mechanical and electrical equipment was consuming 55% of the total power, with the IT infrastructure responsible for the balance. It also unearthed the alarming fact that the amount of power used had doubled in the three years from 2005 to 2008. Worryingly, this analysis also indicated that all the data centres' power capacity would be used up by 2010. What's more, a thermal analysis of Tesco's data centres showed that 70% of chilled air was being wasted through poorly positioned ventilated tiles and poorly adjusted air-conditioning settings.
Having established a baseline for measuring improvements, Deloitte identified a list of efficiency initiatives, categorised into mechanical and engineering enablers, IT, and IT service management best-practice observations. Collectively, these initiatives could reduce power consumption at the data centres by a massive 40% to 50%.
Since Deloitte has delivered its findings, Tesco has wasted no time in rolling out a number of improvements, including the installation of new 'uninterruptible power supply' systems that don't need batteries or cooling and so cut 10% of the data centres' CO2 emissions. Repositioned air tiles with increased ventilation have been installed, and blanking plates, brushes and gaskets control the air circulation, meaning that less energy is needed to cool the air.
Tesco installed a high-density heat-containment system that removes 90% of the carbon emitted from its Wintel estate, and has deployed storage virtualisation technology that will reduce carbon from storage systems by 30%. It also cut power consumption by implementing a programme of server virtualisation, which reduces physical Intel servers by a ratio of about 1:20.
'Deloitte was the first firm we talked to that brought the two disciplines of IT and data-centre efficiency together,' says Mike Yorwerth, Tesco group technology and architecture director. 'Its work has provided us with a baseline against which to measure future improvements, as well as practical and tangible recommendations.'
Tesco's need for ever more computer power ran counter to its commitment to cut carbon emissions, so it drafted in Deloitte to advise on improving the efficiency of its data-centre operations and IT infrastructure. Monitoring generators, air-con and computer functions, Deloitte's Green IT team identified areas of shocking wastage. A list of efficiency initiatives was drawn up which, when implemented, promised to cut power consumption at the data centres by up to 50%. Tesco has been busy putting Deloitte's recommendations into effect.
- Integrate facilities planning and IT management to maximise efficiency and minimise carbon emissions.
- Tailor reports to help the client convince the board and other parties at critical stages.
- Seek opportunities to share infrastructure - buying new hardware for each project isn't always necessary.