Last September, I wrote about web-hosting company Strato and its green credentials. Just before I went on hols (very nice thank you), our beloved leader, Alex, tipped me off about Rackspace, an IT-hosting company which is also busy turning itself green.

So I rummaged.

Strato is based in Germany where it has access to hydroelectric power from the high Rhine and from the mountains of Switzerland. Rackspace, on the other hand, has to be a bit more imaginative. It is building a new data centre in Slough and is doing as much as it considers practical to achieve carbon neutrality.

Since Slough is rather lacking in mountains, Rackspace gets its electricity from Slough Heat and Power, which switched from coal and gas to wood chips and fibre fuel in 2001. The wood supply comes from a mix of renewable sources and waste wood which has no other use. The fibre comes from non-recyclable paper and cardboard. The end result is electricity, hot water and steam for local businesses and residents in and near the Slough trading estate.

In the past ten years, CO2 emissions have shot down from half a million tons to 50,000 as a result of the switch from coal and gas.

Rackspace is designing its new centre in a way that separate sections can be cooled independently. It will also draw on external fresh air when conditions allow. Until now, it has run its operations inside co-location centres and has had no control over this sort of thing. Instead, it has been planting trees - some 300 per month - to offset its carbon emissions. It has chosen less power-hungry computer equipment for its racks and it also does what it can with recycling and usage of green products in its offices.

Well-managed hosting companies will almost certainly run IT operations more effectively, in environmental terms, than a collection of separate data centres housed in individual companies. Organisations that decide to take this route will reduce their capital expenditure and their carbon footprint at a stroke. So, if you are tempted by outsourcing (and you’ll find plenty of other benefits), it’s worth adding ‘green culture’ or similar to your list of desirable provider attributes.