Technology is being tested that allows heat generated by computers to warm offices and homes.
IBM has launched a trial in Switzerland that could see the heat produced by large datacentres being recycled to heat offices.
The three-year trial of the Aquarsar system could reduce carbon emissions by 85% because of lower demand for central heating, and less energy being needed to cool processors inside PCs.
Datacentres are responsible for a large share of global energy consumption. This is growing as use of the internet grows and developing countries strengthen their technology industries and infrastructures.
The Guardian reported that in 2005 datacentres were responsible for 1% of global electricity consumption - double the figure of five years earlier. The figure is thought to be rising rapidly but it is not totally clear by how much because companies often will not disclose how many datacentres they run and how much energy they use.
Tom Dowdall, green electronics campaign co-ordinator at Greenpeace, said the IBM trial was a good example of what could be achieved. But he added there are not enough incentives for companies to improve the efficiency of their datacentres.
"The main driver for change is the price of electricity because companies want to cut their bills. But in the last couple of years the price has fallen. There's no regulation - there should be more incentives for companies to cut electricity use. This is a good example but it's not enough."
Market analysis firm Datamonitor says green IT could jump ahead during the economic downturn.
The company released research showing that flat IT budgets in 2009 have provided a new motivation for cost cutting green measures.
It said, "Flat IT budget growth means that organisations that face critical datacentre limitations, such as a shortage of floor or rack space, are looking to software or outsourcing alternatives to building new datacentres or upgrading existing facilities."