Top 10 tips for green IT

Large companies usually have geographically distributed data centres, which can be inefficient because of the duplicated overheads involved. One data centre will use less power than two running the same amount of hardware, as lighting and cooling costs will be lower all areas the British Computer Society is investigating with the Carbon Trust.

Consolidation also makes maintenance and installation of new hardware easier, and cuts down on the need for support staff to travel, further reducing energy use. Of course, centralised hardware can be seen as placing all your eggs in one basket, but off-site backup firms can easily solve this problem.

5. Virtualisation

Virtualisation is booming in popularity, and it's easy to see why, as it offers cost reductions in the server room and simplifies maintenance. One of the biggest advantages, though, is in energy savings. By reducing the number of servers needed, and making more efficient use of the ones that are left running, your company can cut down on energy bills and cooling. It's estimated that for every pound spent on hardware from an IT budget, 50 pence is spent on cooling and energy costs, so this can easily add up.

Currently, the average server uses less than 55 per cent of its potential, and with dual core processors becoming the norm this is only going to get worse, as many applications are ill-equipped to take advantage of multiple cores. Virtualisation leader VMware claims that the average consolidation ratio is 10 to one a single server can run the workload of ten standard servers as virtual machines. Virtual machines can even be moved from one server to another in real time, so even more servers can be shut off at night or during holidays when demand decreases.

6. Home working

Home working is an idea that has gained a lot of momentum since the wide-scale adoption of home broadband. With almost all office work now done on a PC, it's possible for staff to sign in and work seamlessly, no matter where they are.

This has several benefits. The demand for space and power in the office will go down, saving significantly in rent and utility charges.

But there's an ulterior motive, too. BT admitted in a recent investigation of home-working that 60 per cent of the time employees saved by not having to travel, they ended up giving back by working extra hours. And Microsoft has recently found in a separate study that home working can save employees 500 a year.

Whatever the true motivation, in the next few years employers will further embrace the idea that work is an activity, not a building.

7. Server rooms

As the cost of running and cooling servers is so high, huge energy savings can be made by making the server room more efficient. The more time and money invested in this, the greater the savings, but small changes can be put into practice immediately.

For a start, most server rooms are brilliantly lit, all day, every day, for no reason. Installing motion-sensitive lighting can, over long periods of time, reduce a company's energy use considerably.

Closing any leaks in air conditioning systems can also help, and companies can be brought in to monitor airflow and make suggestions on new layouts that will make greater use of the cooling power you already have, by identifying any hot spots.