Businesses are on a mission to improve the energy efficiency of data centres and save money, according to data centre operator Digital Realty Trust.

The operator has 12 million square feet of datacentre space, mostly in the USA with some in Europe. This is used by corporate customers such as Yahoo and eBay.

The report, scheduled to be released in mid September, surveyed senior executives at 100 large companies to assess their green data centre intentions and found:

Over half have already established strategies to increase energy efficiency
They have green data centre plans
They have senior-level management support
The green strategies are supported by budgets
Sixty percent agreed vendor selection would be affected by their energy-efficiency strategy.

Enterprises face data centre computing resource growth being limited by cost, space and power capacity pressures. Ceilings are being reached on the electricity supply needed to power devices and cool the data centre. Data centres are also filling up with server boxes. The US Environmental Protection Agency predicted that data centre energy supply costs will grow to $7.4 billion in 2011, from the total of $4.5 billion in 2006.

Reducing data centre electricity needs will lower supply costs and raise the ceiling on computing resource growth. Lower energy needs translates into reduced carbon emissions, which in turn will help with global warming. But the drivers for the effort to bypass data centre computing resource ceilings and save electricity supply costs, are not purely environmentalism.

Digital Realty Trust (DRT) engineering VP Jim Smith discussed the company's green data centre ideas in a Infoworld webcast recently. He said: "A data centre is an incredibly energy-intensive machine. ... Green equals efficient. ... increasing efficiency on my energy use saves money on the bottom line."

For an operator such as DRT, the desire by business to 'green' data centres in this way has significant cost implications, as any serious change costs a lot of money. For example, to move into the cooled pod environment, as used by Sun will mean spending money revising cooling systems and amending internal data centre structures, such as putting server racks into enclosed modules.

Currently DRT is highlighting responses such as server consolidation through virtualisation which will lower the number of servers in a data centre. It is also putting forward relatively simple, and for it, inexpensive measures, such as turning the room thermostat up 3 degrees so the cooling energy load is lessened.