The role of cabling in CO2 reduction

Harry Forbes is Chief Technology Officer at Nexans Cabling Solutions and was educated in electrical and electronic engineering. He has worked in the cabling and networking industries for the past 30 years in various technical roles, and has extensive knowledge of and expertise in enterprise systems and data centre infrastructure requirements.

This month (April) sees the introduction in the UK of the much talked about Carbon Reduction Commitment (CRC). The scheme has been launched by the UK Government as part of its aim to reduce greenhouse gas emissions by at least 80% from 1990 levels by 2050. Around 20,000 UK companies are expected to be affected by the scheme, which targets the heaviest energy users - those consuming more than 6,000 Mega-Watt Hours (mwh) per year. These organisations will be required to measure and report their energy consumption, and purchase allowances from the Government for every tonne of CO2 they emit. The CRC will operate as a cap and trade scheme where participants can either buy or sell allowances through a mandatory auction-based emissions trading scheme. The first sale of allowances will be in April 2011 and will cover emissions for 2010 and 2011.

No other European country has a mandatory reporting scheme and the US is yet to implement its planned legislation. However in an attempt to address the energy consumption required by data centres, Europe does have the EU Code of Conduct for Data Centres and there's also The Green Grid, a consortium of global IT firms that have got together to promote data centre efficiency.

The reason data centres are centre stage when it comes to CO2 emissions is obvious: worldwide they are expected by 2020 to consume around 450 billion kWh and 300 million tonnes of CO2 emissions - equal to those of Portugal, Switzerland, Greece and Sweden combined. Understandably, organisations are not prepared to turn back the clock in their desire for more reliable computer services whether for inevitable computerisation of business processes, meeting legal requirements to record processes, Web 2.0 activities, online retailing or just the need for always-up systems.

The EU Code of Conduct on Data Centres is essentially a set of practical guidelines to improve energy efficiency within the data centre industry. The code aims to inform and stimulate data centre operators and owners to reduce energy consumption in a cost-effective manner without hampering the mission critical function of data centres.

In the past organisations requiring more energy simply built new data centres when the need arose but awareness around power consumption means that data centre expansion is no longer a sustainable option. Measures need to be taken to look at expanding capacity without growing energy consumption.

And if Government and corporate social responsibility pressure wasn't enough, the very real situation of rising energy bills will mean that data centre operators will be forced to act as the Board demands to know where company money is being spent and as mwh translate into reduced profit!  Action therefore needs to be taken to stem the acceleration of year on year power consumption.

Reducing consumption

Server consolidation and virtualisation is one route to reducing power consumption. The Uptime Institute estimates that up to 30% of servers running in today's data centres are unused but continue to be powered, using approximately 70 per cent of their fully rated power load despite sitting idle. Significant savings can therefore be made through consolidation. However, the use of blade servers and cluster computing can cause energy problems with servers needing to be close together due to the short reach of the I/O interconnect - typically 7m -15m. The net result can be poor power load balancing and cooling resulting in hotspots and power inefficiencies. 10GBase-T as a server-to-server interconnect is a potential solution to this problem. Recent advancements in transceiver chipsets and initiatives by IEEE802.3az Energy Efficient Ethernet Task Group have brought about a significant reduction in transceiver power with more improvements underway. Ethernet is now a viable option for high performance cluster computing and storage applications with Fibre Channel over Ethernet.

The 100m reach of 10GBase-T enables servers used in cluster computing to be dispersed throughout the data centre allowing system designers to optimise load balancing and cooling accordingly. This has the potential for reduced power at greater efficiency and can aid in reducing hotspots and therefore the need for cooling which can be around half a data centre's energy use.

Another energy reducer is the wake-on LAN (WOL) feature where the server is powered down when idle and a small fraction of standby power is applied to the network card. When a 'magic packet' is received the network card restarts the computer. With servers using enormous power even when sitting idle, this represents significant energy and cost savings. Energy Efficient Ethernet will drive energy consumption and costs down as power is better utilised, managed and made available on a need by need basis.

Knowing consumption

Research reports consistently show that the majority of data centre managers and IT directors are oblivious to the costs of running their own data centres. One step to solving this would be the deployment of Intelligent Infrastructure Management (IIM) and Environmental Monitoring and Control (EMAC) tools. By automatically recording various environmental attributes using analysis features, a highly accurate carbon footprint can be calculated and examined for corrective action.

Cable

The right choice of cable can also make a difference to CO2 emissions. Shielded cabling technology is less affected by external interference or noise and therefore needs less noise cancellation properties, which means less energy is required for each cable. The superior internal cross talk of Cat7A allows noise cancellers to be turned down creating potential energy savings of up to 35% over Cat6A when taking advantage of enhanced Digital Signal Processing (DSP) design.

Future proofing a data centre will also help in the CO2 emissions war. With pressure for the data centre shelf life to rise from 15 to 50 years IT professionals should consider using the very latest cable technology. Installing Cat6A cabling will only give a data centre a life of six years, but investing in Cat7A will ensure a longer shelf life and the ability to move from 10G to 40G.

Time to act

The UK and quite soon the US might be leading the way on energy reducing legislation but unless voluntary schemes and industry collaboration across the globe are effective then other nations will be looking at harsh Government intervention. Now is the time to act to hold on to self-regulation.