Oct. 17--When Jonathan Koomey began thinking about power consumption in the information technology industry, he didn't expect to come up with the energy equivalent of Moore's Law, the observation of Intel co-founder Gordon Moore in 1965 that the number of transistors that could be cost-effectively put on an integrated circuit would double every two years. But he may have done just that.

Koomey, a researcher affiliated with Stanford University and Lawrence Berkeley National Laboratory in Berkeley and currently visiting professor at Yale University, is co-author of three recent studies into the growing power requirements of the information technology industry -- a source of growing concern as evidence mounts that energy use is contributing to the greenhouse effect.

Koomey's study warned that the power-related costs of data centers would soon be larger than the cost of the IT equipment in them. A second study compared the cost of downloading a CD with buying one at a store, finding that the energy and CO2 emissions created by a download were much smaller than those associated with buying a physical CD. That illustrated how digitizing something could create cost, energy and emissions savings that ripple through the rest of the economy.

The final study explored the relationship between the processing power of computers (which in the microprocessor era has been driven by Moore's Law) and the electricity required to deliver that performance.

Q The energy consumption

of the IT industry is of growing concern. Some people worry that it will ultimately force limits on the computing industry. Others are more concerned with the global effect of the power that the IT industry requires. What does your research tell us about where we're headed?

A Let's start with data centers. Research in 2007 shows that from 2000 to 2005, power use essentially doubled to 1.5 percent of U.S. electricity use. That is pretty rapid growth. At the same time, the industry started to really wrestle with this problem and focus on efficiency. And they found out that data center costs are driven as much by power use as by the cost of the IT equipment.

Q Why did it take so long to wake up to this?

A In many data centers, the IT department makes decisions about what IT equipment to buy but doesn't care one whit for efficiency because they aren't paying the electric bill or buying the cooling equipment (the facilities department has a separate budget for those expenses). This leads to bad results for both corporate profits and the environment.