Oversimplified.(Your letters: our readers speak out)(Letter to the Editor)

Dear Editor:

I am the lead author of the ADL study referenced in Michael Thelander's article, "Desktop Energy Uses Add to Energy Bills" (March). I am glad that EUN has published an article about ICT energy consumption and agree with the top-level point of the article: underutilization of power-management capabilities cause ICT devices, most notably desktop PCs, to waste an appreciable quantity of energy.

I did notice a few incorrect characterizations of our 2002 study.

First, the statement that "ICT equipment was responsible for only 3% of national energy consumption" is incorrect. Our (ADL) study estimated that nonresidential ICT equipment accounted for just under 3% of national electricity consumption, which equals just over 1% of national energy consumption. This is an important distinction.

Second, our study found that all ICT equipment accounts for about 9% of commercial building energy consumption; the article attributes all of this electricity consumption to PCs only.

Third, the article indicates that "PCs and monitors at work in nonresidential spaces consume 41.8 TWh of energy a year in this sector," according to ADL and LBNL research.

This data point appears to be based on our (ADL) study and not the LBNL study, so it is not consistent with figure 1 or figure 2 (which both come from LBNL, ...