The San Francisco Bay Area's naturally cool weather could help IT managers cut electricity costs. But Mark Bramfitt, who manages energy reduction programs for the high-tech sector at Pacific Gas & Electric Co., knows that most data centres are walled off from green alternatives.

"Here we are on the coast of California, and today it is 55 degrees and raining -- and all the data centres I can see in my area here are running their chiller plants," Bramfitt said yesterday.

Data centres in PG&E's service area -- which includes the Bay Area and much of Northern California -- use as much as 500 megawatts of power per year, the utility estimates. With power-reduction efforts, such as cooling systems that draw in outside air instead of relying on air produced by chillers, that power use could be cut by as much as half, said Bramfitt.

But data centre operators fear switching from a chiller to "free cooling," according to Kevin O'Brien, executive vice president of The Structure Tone Organization, a data centre building company in New York. Free cooling isn't the same as opening a window, and air may still have to be regulated for moisture, for instance. The potential problem for IT managers is that when a switchover occurs, IT departments face increased risks of a failure, said O'Brien.

O'Brien, who was at the Afcom data centre conference in Las Vegas, believes IT managers need to be more aggressive about reducing power consumption and considering alternatives. "We need to police ourselves [and define] what is the green data centre ... before the government tells us what it's going to be," he said.

Mark Wood, director of infrastructure management at Highmark, the parent company of Blue Cross/Blue Shield, said environmental concerns are high on his list. He asks all his vendors whether they are compliant with regulations such as the Restriction of the Use of Certain Hazardous Substances (RoHS). RoHS, which took effect last year, refers to a European directive that restricts waste from electronics and bars the import of lead, mercury and cadmium in components.

Wood also asks vendors about the energy consumption of their products. He virtualises his environment, with the goal of reducing his 500 physical servers by half.

"Our kids are being challenged with all of this -- we're leaving our legacy," said Wood.

PG&E is trying to get data centres to cut power consumption by offering incentives. In November, it said it would offer up to $4 million in electric rebates to companies that cut the number of physical servers they use and move to virtualisation. A data centre that requires less energy reduces the need for PG&E to purchase extra power during peak demands -- power that may come from less environmentally clean sources, such as jet engines used to run turbines.

Bramfitt said he has about three dozen applications from companies to participate in the incentive program, with some using just a few servers and others that use up to 6,000. Bramfitt is shooting for an initial power savings of four to five megawatts a year.

Last week, PG&E announced the first data centre to participate in its Critical Peak Pricing Program, which is designed to reduce energy demand. The company, 365 Main Exchange, leases data centre space and has designed a generator-testing methodology to cut its electricity bill.

San Francisco-based 365 Main has participated in other PG&E power reduction programs. It has installed lighting controls that automatically turn off lights and variable-frequency drives on air conditioning motors to incrementally control power usage. For instance, if an air conditioner is only working at about 30 per cent of capacity, it will use an equal amount of power.

But the major savings came from a change in the company's generator-testing methodology for its 10 continuous power generators. It cut its power costs between May and October of last year by $70,000, and reduced its 10 megawatt load by about 1 megawatt, according to Miles Kelly, 365 Main's vice president of marketing. The company also times its monthly, week-long test during those periods when PG&E expects high energy usage because of the weather.

With its old methodology, 365 Main Street sent all of the energy produced by a generator to a load bank. The new system uses some of the power produced during the testing to reduce demand on the utility while still meeting the company's own power needs.