Technical solutions for a greener future

The good news for the motivated IT head is that there is a smorgasbord of energy-saving technologies that are relatively cheap to implement and produce quick returns – the low-hanging fruit that Gartner calls “phase 1 green IT”.

Some of these technologies were designed to achieve other aims, and it just so happens that they also reduce the energy consumed for any given unit of data processed.

For example, the rapid uptake of virtualisation among data-heavy firms after 2003 had more to do with saving space than energy. While hardware costs plummeted, office rents skyrocketed, so reducing server sprawl made economic sense.

Server and storage virtualisation still makes economic sense in terms of energy consumption. In a packed server room yet more power vanishes into lossy power transmission systems. This can be minimised through high-performance uninterruptible power supplies (UPS).

Storage can be similarly consolidated and de-duplicated to reduce capacity (and hence the number of spinning disks) and managed hierarchically to transfer less critical data off power-hungry high-performance disks onto low-power Serial ATA (SATA) drives.

Switching off and removing unused equipment from the server room also reduces power consumption.

Keep cool
A lot of effort has gone into improving cooling, not just the performance of computer room air conditioning (CRAC) systems, but also the layout of the computer room with alternating contained cold and hot aisles.

A healthy trade in thermal analysis and power management services and software has blossomed around this trend, not just for the sake of energy efficiency, but because it improves datacentre reliability.

“Knowing that a rack is near its power limit can forewarn against a potential overload that could cost money in downtime,” says Philip Petersen, chief executive of Adinfa, which provides technology to monitor datacentre energy consumption.

“Monitoring and trending power usage over time helps you to understand how changes affect the datacentre and how to optimise operations.”

Measurement
Of course, managing datacentre energy efficiency requires its measurement and, to date, the best metric developed for that has been power usage effectiveness (PUE),  a measure that shows the total energy used by a datacentre divided by the energy used by ICT equipment in that datacentre. But it has its critics.

“Where is it measured? What’s included or excluded? All PUE tells us is the overhead of air conditioning and power distribution, not the efficiency of the datacentre operations themselves,” says Simon Mingay, research vice president at Gartner.

The Green Grid has done a lot of work in establishing PUE as the defining metric, publishing the initial spec in 2007 and fleshing it out with hefty white papers and guidelines. This culminated in the Recommendations for Measuring and Reporting Overall Data Center Efficiency – Version 1 – Measuring PUE at Dedicated Data Centers published in July 2010 by a task force that included the US Environmental Protection Agency, Energy Star Programme, Green Building Council and a host of IT vendors as well as the Green Grid.

But even the Green Grid recognises PUE’s limitations and has published two new metrics: carbon usage effectiveness (CUE) and water usage effectiveness (WUE) to be discussed at the consortium’s technical forum in March.

Desktop estate
Client computing also offers quick energy savings. If automated power-off tools are considered too draconian, then training users to switch off PCs when they leave the office would yield big savings, as would banning screen savers in favour of allowing monitors to revert to stand-by mode.

Some organisations have gone further, using desktop virtualisation and replacing power-hungry PCs with thin clients that draw less power and consequently lower the demand for air conditioning.

Replacing individual printers and scanners with multifunction devices shared among workgroups can also reduce client-side energy consumption.

Holistic view
All the technologies above – and there are numerous others – can accumulate significant energy savings, and most organisations have adopted at least some. In its report Where Will Green IT Be at Year-End 2010? Gartner estimates “phase 1 is complete or nearing completion at 15 to 20 per cent of all IT organisations.”

But these are piecemeal efforts and Gartner’s Mingay laments the industry’s lack of ambition.
“What is disappointing is the lack of disruptive innovation. We are just seeing incremental improvements and there is an opportunity to do better,” he says.

Gartner defines phase 2 green IT as the integration of energy management into everything IT touches, from project development to routine maintenance, from product procurement to disposal. That requires not so much a change in technology as a change in attitude by senior management and a change in behaviour by users.