Half of IT executives admit that their firms do not monitor IT-related energy spending, according to a new report from the Economist Intelligence Unit (EIU).

The research explored the efforts being made by organisations to measure and reduce the environmental impact of IT infrastructures.

Nearly one in four of those companies that do monitor IT energy consumption have actually seen their consumption rise over the past two years.

Recent reports suggest that power is becoming the single most important factor in data centre operating costs.

But the survey shows that, despite the high profile of environmental issues, few companies have anything approaching a cohesive strategy for dealing with power costs from an IT perspective.

However, the EIU report warned that rising energy costs and a growing demand for power are likely to put energy concerns much higher on the agenda.

"Concerns about energy efficiency and global warming are now high on the political agenda, but the spotlight has not yet been turned on the IT function, " said James Watson, manager for industry client research at the EIU, and editor of the report.

"This survey suggests that few firms have woken up to the fact that their IT infrastructure is already responsible for a significant proportion of their total energy costs."

The US Environmental Protection Agency noted recently that servers and data centres in the US accounted for 1.5 per cent of the country's electricity consumption in 2006.

This amounted to around $4.5bn worth of electricity, more than double that consumed in 2000.

Survey respondents put the blame partly on the lack of visibility about the issue. Around two-thirds said that an industry standard on energy efficiency for IT equipment would prompt them to change their procurement policies.

"There is a growing business and legislative need for CIOs to look at their own organisations to ensure that IT systems and services are as energy efficient as possible," said Richard Lanyon-Hogg, chief technical officer for green services at IBM.

"Recent client engagements, and this report, confirm that many organisations are unsure as to how to measure their IT carbon footprint and bring about sustainable improvements."

This trend looks likely to change as more high-profile companies such as Google, Dell and Strato set out clear plans to minimise or even neutralise carbon emissions.