Jerome Baddley reports on the expansion of energy-hungry datacentres and how a project in Nottingham might be able to satisfy their appetite yet cut emissions
The world's information is doubling every two years and with that comes a huge demand for new datacentre infrastructure. More than 9% of global investment in datacentres is in the UK. Around $16.95 billion is expected to be invested in new UK capacity in 2015 alone, up 4.3% on the 2014 levels of expenditure and 9.3 higher than in 2013.
The IT industry is under pressure to reduce its energy consumption. According to a report published by McKinsey in 2010, the sector consumes 2% of the world's energy and by 2020 will generate as much carbon as the airline industry.
Datacentres operate around the clock and, in the UK, would consume 27.5TWh of electricity each year if fuelled by the national grid and be responsible for 15.2 million tonnes of CO2 equivalent (mtCO2e) emissions. This is more than half the total footprint of the NHS and its entire supply chain (25 mtCO2e), and greater than that of Costa Rica. However, not all datacentres are supplied by grid power; some off-grid centres may have diesel or fuel oil systems.
A promising approach to reducing the carbon impact of data-intensive industries is being explored in Nottingham by environmental consultancy NetPositive in partnership with 2BM, which installs datacentres. It comes as operator concern grows about the sector's environmental impact. An annual survey found "to be greener and more sustainable" ranked second after "to reduce operating costs" as the reason given for investment in datacentre facilities in 2014 and 2015. Indeed, in those years the proportion citing environmental concerns increased from 31% to 35%.
Going local
The rise in the number of datacentres has sparked pressure from environmental groups and facilities managers to reduce power consumption at critical sites. With the UK consuming almost 7% of worldwide datacentre power, it is clear that measures must be taken to slow this ever-rising figure. At the same time, constrained power supply means that central London is reaching datacentre capacity and regional facilities are being considered for Slough, Birmingham, Manchester and Leeds. According to Tariff Consultancy, the European datacentre market monitor, these areas are likely to see clusters of service providers, each developing their own digital ecosystem. Datacentres outside London already account for 56% all "raised floor space" in the UK, and this is set to continue.
2BM, based in Nottingham, has recently built what is claimed to be the world's most efficient datacentre in Cambridge for microprocessor design business ARM, using water-based rather than mechanical cooling. It is now looking at creating power-efficient, low-carbon datacentre facilities using district-heating systems in places like Nottingham. In summer, a district heating network is an ideal source of excess heat, which could be used for adsorption cooling at information communications and technology data storage centres.
Nottingham is already a UK leader for urban energy self-sufficiency, with around 15% of the city's consumption generated within its limits and the council operating the country's largest district heating network. Nottingham was also identified this year as having the fastest falling CO2 emissions of any city in the UK, down 21% since 2005.
Initial modelling by sustainability partnership NetPositive looked at two types of datacentre: national grid-dependent (tiers 1 and 2) and national grid-independent (tiers 3 and 4). Costs, energy and emissions were estimated for datacentres supplied with electricity from the grid and those powered by diesel generators (grid-independent). For a grid-dependent datacentre connected to the Nottingham heating network, estimated annual running cost savings were £200,000, while potential carbon equivalent savings totalled 1,000 tonnes. The equivalent savings for grid-independent datacentres were £2 million and 3,500 tonnes CO2e.
The initial analysis suggests the running costs of a datacentre in Nottingham that uses CHP absorption chillers and is connected to the heating network would be more than 30% lower than one that was grid-dependent.
The UK heat strategy (The future of heating: a strategic framework for low-carbon heat) and Carbon plan include the development of low-carbon heat through district networks in towns and cities. The national strategies are reflected in the local plans and in Nottingham's 2020 energy strategy, written by the NetPositive team and published by the city council in April 2010, as well as the draft low-carbon plan from Local Enterprise Partnership, published in 2013.
The support for companies such as 2BM to innovate in lower-carbon solutions forms part of the broad approach to low-carbon jobs and growth in Nottinghamshire and Derbyshire, primarily delivered through the region's new Low Carbon Hub. The aim of the hub, which launched in June, is to link businesses to appropriate sources of help and to foster collaborations across the low-carbon sector.
A 1.9MW datacentre would cost £26 million, but create between 100 and 300 skilled IT and facilities management jobs. Datacentres are only the physical embodiment of a digital services business that employs many more people than the onsite staff. If the UK can demonstrate expertise and a rapidly deployable solution to low-carbon datacentres, it should expect to generate a significant number of construction and operation jobs where these solutions are deployed. Further employment could be created as local companies export the expertise they develop.
The rise of the powerful datacentres |
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The European commission's joint research centre estimates that, between 2007 and 2020, electricity consumption in western Europe's datacentres will increase from 56 Terawatt hours (TWh) to 104 TWh. In the UK, the power demand of datacentres is set to grow to 3.15GW by the end of the year. To put this figure in context, the capacity of Drax, the UK's largest power station, is 3.9GW. |
Datacentre efficiency |
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PUE is defined as total facility power divided by IT equipment power, which is the power consumed by equipment to manage, process and store data. Total facility power includes everything that supports the IT equipment load, such as cooling systems, including chillers, air conditioning and lighting. The PUE is a quick way to compare energy allocation in a datacentre. If a PUE is determined to be 2.0, this suggests that demand is two times greater than the energy necessary to power the actual IT equipment. A PUE can range from 1.0 to infinity. A PUE value approaching 1.0 would indicate 100% efficiency. Research suggests an average PUE in the EU of 1.78. In recent years, the density of processing power in datacentres has increased dramatically. To match this, the intensity of associated services, such as electricity demand and cooling demand per m2, have also had to increase. This high and climbing grid power demand is a primary reason behind the limits on datacentre capacity in some towns and cities. In response to the projected rise in electricity consumption by datacentres in the EU, the European commission has developed a best practice code of conduct. The aim is to encourage datacentre owners and operators to have the energy efficiency of their operations measured and agree an action plan and annual progress report. |
Two metrics have been adopted by the industry to measure the energy efficiency of datacentres: power usage effectiveness (PUE) and datacentre efficiency (DCE).
